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Yang K, Zhu L, Liu C, Zhou D, Zhu Z, Xu N, Li W. Current status and prospect of the DNA double-strand break repair pathway in colorectal cancer development and treatment. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167438. [PMID: 39059591 DOI: 10.1016/j.bbadis.2024.167438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 07/18/2024] [Accepted: 07/18/2024] [Indexed: 07/28/2024]
Abstract
Colorectal cancer (CRC) is one of the most common malignancies worldwide. Double-strand break (DSB) is the most severe type of DNA damage. However, few reviews have thoroughly examined the involvement of DSB in CRC. Latest researches demonstrated that DSB repair plays an important role in CRC. For example, DSB-related genes such as BRCA1, Ku-70 and DNA polymerase theta (POLQ) are associated with the occurrence of CRC, and POLQ even showed to affect the prognosis and resistance for radiotherapy in CRC. This review comprehensively summarizes the DSB role in CRC, explores the mechanisms and discusses the association with CRC treatment. Four pathways for DSB have been demonstrated. 1. Nonhomologous end joining (NHEJ) is the major pathway. Its core genes including Ku70 and Ku80 bind to broken ends and recruit repair factors to form a complex that mediates the connection of DNA breaks. 2. Homologous recombination (HR) is another important pathway. Its key genes including BRCA1 and BRCA2 are involved in finding, pairing, and joining broken ends, and ensure the restoration of breaks in a normal double-stranded DNA structure. 3. Single-strand annealing (SSA) pathway, and 4. POLθ-mediated end-joining (alt-EJ) is a backup pathway. This paper elucidates roles of the DSB repair pathways in CRC, which could contribute to the development of potential new treatment approaches and provide new opportunities for CRC treatment and more individualized treatment options based on therapeutic strategies targeting these DNA repair pathways.
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Affiliation(s)
- Kexin Yang
- Department of Colorectal Surgery, the Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming 650106, China; Kunming Medical University, Kunming 650500, China
| | - Lihua Zhu
- Department of Surgical Oncology, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, China; Kunming Medical University, Kunming 650500, China
| | - Chang Liu
- Department of Surgical Oncology, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - Dayang Zhou
- Department of Surgical Oncology, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - Zhu Zhu
- Department of Surgical Oncology, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - Ning Xu
- Department of Colorectal Surgery, the Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming 650106, China; Department of Surgical Oncology, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, China; Kunming Medical University, Kunming 650500, China.
| | - Wenliang Li
- Department of Colorectal Surgery, the Third Affiliated Hospital of Kunming Medical University, Yunnan Cancer Hospital, Kunming 650106, China; Kunming Medical University, Kunming 650500, China.
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2
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Ito F, Li Z, Minakhin L, Chandramouly G, Tyagi M, Betsch R, Krais JJ, Taberi B, Vekariya U, Calbert M, Skorski T, Johnson N, Chen XS, Pomerantz RT. Structural basis for a Polθ helicase small-molecule inhibitor revealed by cryo-EM. Nat Commun 2024; 15:7003. [PMID: 39143110 PMCID: PMC11324745 DOI: 10.1038/s41467-024-51351-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 08/05/2024] [Indexed: 08/16/2024] Open
Abstract
DNA polymerase theta (Polθ) is a DNA helicase-polymerase protein that facilitates DNA repair and is synthetic lethal with homology-directed repair (HDR) factors. Thus, Polθ is a promising precision oncology drug-target in HDR-deficient cancers. Here, we characterize the binding and mechanism of action of a Polθ helicase (Polθ-hel) small-molecule inhibitor (AB25583) using cryo-EM. AB25583 exhibits 6 nM IC50 against Polθ-hel, selectively kills BRCA1/2-deficient cells, and acts synergistically with olaparib in cancer cells harboring pathogenic BRCA1/2 mutations. Cryo-EM uncovers predominantly dimeric Polθ-hel:AB25583 complex structures at 3.0-3.2 Å. The structures reveal a binding-pocket deep inside the helicase central-channel, which underscores the high specificity and potency of AB25583. The cryo-EM structures in conjunction with biochemical data indicate that AB25583 inhibits the ATPase activity of Polθ-hel helicase via an allosteric mechanism. These detailed structural data and insights about AB25583 inhibition pave the way for accelerating drug development targeting Polθ-hel in HDR-deficient cancers.
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Affiliation(s)
- Fumiaki Ito
- Molecular and Computational Biology, Department of Biological Sciences and Chemistry, University of Southern California, Los Angeles, California, CA, 90089, USA
| | - Ziyuan Li
- Molecular and Computational Biology, Department of Biological Sciences and Chemistry, University of Southern California, Los Angeles, California, CA, 90089, USA
| | - Leonid Minakhin
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Gurushankar Chandramouly
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Mrityunjay Tyagi
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Robert Betsch
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - John J Krais
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Bernadette Taberi
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Umeshkumar Vekariya
- Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Marissa Calbert
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Tomasz Skorski
- Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Neil Johnson
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Xiaojiang S Chen
- Molecular and Computational Biology, Department of Biological Sciences and Chemistry, University of Southern California, Los Angeles, California, CA, 90089, USA.
| | - Richard T Pomerantz
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA.
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3
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Willman GH, Xu H, Zeigler TM, McIntosh MT, Bhaduri-McIntosh S. Polymerase theta is a synthetic lethal target for killing Epstein-Barr virus lymphomas. J Virol 2024; 98:e0057224. [PMID: 38860782 PMCID: PMC11265443 DOI: 10.1128/jvi.00572-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/27/2024] [Indexed: 06/12/2024] Open
Abstract
Treatment options for Epstein-Barr virus (EBV)-cancers are limited, underscoring the need for new therapeutic approaches. We have previously shown that EBV-transformed cells and cancers lack homologous recombination (HR) repair, a prominent error-free pathway that repairs double-stranded DNA breaks; instead, EBV-transformed cells demonstrate genome-wide scars of the error-prone microhomology-mediated end joining (MMEJ) repair pathway. This suggests that EBV-cancers are vulnerable to synthetic lethal therapeutic approaches that target MMEJ repair. Indeed, we have previously found that targeting PARP, an enzyme that contributes to MMEJ, results in the death of EBV-lymphoma cells. With the emergence of clinical resistance to PARP inhibitors and the recent discovery of inhibitors of Polymerase theta (POLθ), the polymerase essential for MMEJ, we investigated the role of POLθ in EBV-lymphoma cells. We report that EBV-transformed cell lines, EBV-lymphoma cell lines, and EBV-lymphomas in AIDS patients demonstrate greater abundance of POLθ, driven by the EBV protein EBNA1, compared to EBV-uninfected primary lymphocytes and EBV-negative lymphomas from AIDS patients (a group that also abundantly expresses POLθ). We also find POLθ enriched at cellular DNA replication forks and exposure to the POLθ inhibitor Novobiocin impedes replication fork progress, impairs MMEJ-mediated repair of DNA double-stranded breaks, and kills EBV-lymphoma cells. Notably, cell killing is not due to Novobiocin-induced activation of the lytic/replicative phase of EBV. These findings support a role for POLθ not just in DNA repair but also DNA replication and as a therapeutic target in EBV-lymphomas and potentially other EBV-cancers as EBNA1 is expressed in all EBV-cancers.IMPORTANCEEpstein-Barr virus (EBV) contributes to ~2% of the global cancer burden. With a recent estimate of >200,000 deaths a year, identifying molecular vulnerabilities will be key to the management of these frequently aggressive and treatment-resistant cancers. Building on our earlier work demonstrating reliance of EBV-cancers on microhomology-mediated end-joining repair, we now report that EBV lymphomas and transformed B cell lines abundantly express the MMEJ enzyme POLθ that likely protects cellular replication forks and repairs replication-related cellular DNA breaks. Importantly also, we show that a newly identified POLθ inhibitor kills EBV-cancer cells, revealing a novel strategy to block DNA replication and repair of these aggressive cancers.
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Affiliation(s)
- Griffin H. Willman
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, Florida, USA
| | - Huanzhou Xu
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, Florida, USA
| | - Travis M. Zeigler
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, Florida, USA
| | - Michael T. McIntosh
- Child Health Research Institute, Department of Pediatrics, University of Florida, Gainesville, Florida, USA
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, USA
| | - Sumita Bhaduri-McIntosh
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, Florida, USA
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, USA
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4
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Vekariya U, Minakhin L, Chandramouly G, Tyagi M, Kent T, Sullivan-Reed K, Atkins J, Ralph D, Nieborowska-Skorska M, Kukuyan AM, Tang HY, Pomerantz RT, Skorski T. PARG is essential for Polθ-mediated DNA end-joining by removing repressive poly-ADP-ribose marks. Nat Commun 2024; 15:5822. [PMID: 38987289 PMCID: PMC11236980 DOI: 10.1038/s41467-024-50158-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 06/27/2024] [Indexed: 07/12/2024] Open
Abstract
DNA polymerase theta (Polθ)-mediated end-joining (TMEJ) repairs DNA double-strand breaks and confers resistance to genotoxic agents. How Polθ is regulated at the molecular level to exert TMEJ remains poorly characterized. We find that Polθ interacts with and is PARylated by PARP1 in a HPF1-independent manner. PARP1 recruits Polθ to the vicinity of DNA damage via PARylation dependent liquid demixing, however, PARylated Polθ cannot perform TMEJ due to its inability to bind DNA. PARG-mediated de-PARylation of Polθ reactivates its DNA binding and end-joining activities. Consistent with this, PARG is essential for TMEJ and the temporal recruitment of PARG to DNA damage corresponds with TMEJ activation and dissipation of PARP1 and PAR. In conclusion, we show a two-step spatiotemporal mechanism of TMEJ regulation. First, PARP1 PARylates Polθ and facilitates its recruitment to DNA damage sites in an inactivated state. PARG subsequently activates TMEJ by removing repressive PAR marks on Polθ.
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Affiliation(s)
- Umeshkumar Vekariya
- Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Leonid Minakhin
- Thomas Jefferson University, Sidney Kimmel Cancer Center, Department of Biochemistry and Molecular Biology, Philadelphia, PA, 19107, USA
| | - Gurushankar Chandramouly
- Thomas Jefferson University, Sidney Kimmel Cancer Center, Department of Biochemistry and Molecular Biology, Philadelphia, PA, 19107, USA
| | - Mrityunjay Tyagi
- Thomas Jefferson University, Sidney Kimmel Cancer Center, Department of Biochemistry and Molecular Biology, Philadelphia, PA, 19107, USA
| | - Tatiana Kent
- Thomas Jefferson University, Sidney Kimmel Cancer Center, Department of Biochemistry and Molecular Biology, Philadelphia, PA, 19107, USA
| | - Katherine Sullivan-Reed
- Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Jessica Atkins
- Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Douglas Ralph
- Thomas Jefferson University, Sidney Kimmel Cancer Center, Department of Biochemistry and Molecular Biology, Philadelphia, PA, 19107, USA
| | - Margaret Nieborowska-Skorska
- Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Anna-Mariya Kukuyan
- Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Hsin-Yao Tang
- Proteomics and Metabolomics Facility, The Wistar Institute, Philadelphia, PA, 19104, USA
| | - Richard T Pomerantz
- Thomas Jefferson University, Sidney Kimmel Cancer Center, Department of Biochemistry and Molecular Biology, Philadelphia, PA, 19107, USA.
| | - Tomasz Skorski
- Fels Cancer Institute for Personalized Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA.
- Department of Cancer and Cellular Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA.
- Nuclear Dynamics and Cancer Program, Fox Chase Cancer Center, Philadelphia, PA, USA.
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5
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Carvajal-Maldonado D, Li Y, Returan M, Averill AM, Doublié S, Wood RD. Dynamic stem-loop extension by Pol θ and templated insertion during DNA repair. J Biol Chem 2024; 300:107461. [PMID: 38876299 PMCID: PMC11292364 DOI: 10.1016/j.jbc.2024.107461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/26/2024] [Accepted: 05/28/2024] [Indexed: 06/16/2024] Open
Abstract
Theta-mediated end joining (TMEJ) is critical for survival of cancer cells when other DNA double-stranded break repair pathways are impaired. Human DNA polymerase theta (Pol θ) can extend ssDNA oligonucleotides, but little is known about preferred substrates and mechanism. We show that Pol θ can extend both ssDNA and RNA substrates by unimolecular stem-loop synthesis initiated by only two 3' terminal base pairs. Given sufficient time, Pol θ uses alternative pairing configurations that greatly expand the repertoire of sequence outcomes. Further primer-template adjustments yield low-fidelity outcomes when the nucleotide pool is imbalanced. Unimolecular stem-loop synthesis competes with bimolecular end joining, even when a longer terminal microhomology for end joining is available. Both reactions are partially suppressed by the ssDNA-binding protein replication protein A. Protein-primer grasp residues that are specific to Pol θ are needed for rapid stem-loop synthesis. The ability to perform stem-loop synthesis from a minimally paired primer is rare among human DNA polymerases, but we show that human DNA polymerases Pol η and Pol λ can catalyze related reactions. Using purified human Pol θ, we reconstituted in vitro TMEJ incorporating an insertion arising from a stem-loop extension. These activities may help explain TMEJ repair events that include inverted repeat sequences.
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Affiliation(s)
- Denisse Carvajal-Maldonado
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Center, Houston, Texas, USA
| | - Yuzhen Li
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Center, Houston, Texas, USA
| | - Mark Returan
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Center, Houston, Texas, USA
| | - April M Averill
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, USA
| | - Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, USA
| | - Richard D Wood
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Center, Houston, Texas, USA.
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6
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Laverty DJ, Gupta SK, Bradshaw GA, Hunter AS, Carlson BL, Calmo NM, Chen J, Tian S, Sarkaria JN, Nagel ZD. ATM inhibition exploits checkpoint defects and ATM-dependent double strand break repair in TP53-mutant glioblastoma. Nat Commun 2024; 15:5294. [PMID: 38906885 PMCID: PMC11192742 DOI: 10.1038/s41467-024-49316-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 05/28/2024] [Indexed: 06/23/2024] Open
Abstract
Determining the balance between DNA double strand break repair (DSBR) pathways is essential for understanding treatment response in cancer. We report a method for simultaneously measuring non-homologous end joining (NHEJ), homologous recombination (HR), and microhomology-mediated end joining (MMEJ). Using this method, we show that patient-derived glioblastoma (GBM) samples with acquired temozolomide (TMZ) resistance display elevated HR and MMEJ activity, suggesting that these pathways contribute to treatment resistance. We screen clinically relevant small molecules for DSBR inhibition with the aim of identifying improved GBM combination therapy regimens. We identify the ATM kinase inhibitor, AZD1390, as a potent dual HR/MMEJ inhibitor that suppresses radiation-induced phosphorylation of DSBR proteins, blocks DSB end resection, and enhances the cytotoxic effects of TMZ in treatment-naïve and treatment-resistant GBMs with TP53 mutation. We further show that a combination of G2/M checkpoint deficiency and reliance upon ATM-dependent DSBR renders TP53 mutant GBMs hypersensitive to TMZ/AZD1390 and radiation/AZD1390 combinations. This report identifies ATM-dependent HR and MMEJ as targetable resistance mechanisms in TP53-mutant GBM and establishes an approach for simultaneously measuring multiple DSBR pathways in treatment selection and oncology research.
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Affiliation(s)
- Daniel J Laverty
- Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | | | | | | | | | | | - Jiajia Chen
- Mayo Clinic, Rochester, MN, 55905, USA
- Shengjing Hospital of China Medical University, Shenyang, 110004, China
| | | | | | - Zachary D Nagel
- Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA.
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7
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Frye CC, Tennant L, Yeager A, Azimzadeh P, Bhardwaj P, Xu Y, Liu J, Othoum G, Maher CA, Chernock R, Goedegebuure SP, Gillanders W, Olson JA, Brown TC. Overexpression of human DNA polymerase theta is a biomarker of aggressive and DNA repair-deficient papillary thyroid cancers. Surgery 2024:S0039-6060(24)00303-9. [PMID: 38897886 DOI: 10.1016/j.surg.2024.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 04/19/2024] [Accepted: 05/05/2024] [Indexed: 06/21/2024]
Abstract
BACKGROUND DNA polymerase theta (POLQ) is an enzyme that repairs double-strand DNA breaks. POLQ is overexpressed in several cancer types, and increased expression is associated with a poor prognosis. Ablating POLQ function in vitro increases drug sensitivity to agents that cause double-strand DNA breaks, including chemotherapies and ionizing radiation. POLQ's role in thyroid cancer remains poorly understood. METHODS Expression of POLQ and other genes of interest were analyzed in 513 papillary thyroid cancers (505 primary tumors and 8 metastatic lesions) and 59 normal thyroid samples available in the Cancer Genome Atlas. The Cancer Genome Atlas RNA and DNA sequencing data were queried with the Xena platform. The Recombination Proficiency Score was calculated to assess DNA repair efficiency. Other signaling events associated with thyroid tumorigenesis and clinical outcomes were analyzed. Univariate and multivariate analyses were performed. Treatment with the POLQ inhibitors ART558 and Novobiocin tested the effect of POLQ inhibition on in vitro thyroid cancer growth. RESULTS POLQ expression was increased in papillary thyroid cancers compared to normal thyroid tissue (P < .05). POLQ expression levels were inversely correlated with Recombination Proficiency Score levels (P < .05). POLQ expression was highest in tall cell papillary thyroid cancers and in metastases. Higher POLQ expression was also associated with dedifferentiation, BRAF signaling, and shorter progression-free intervals (P < .05). Treatment with POLQ inhibitors decreased in vitro thyroid cancer growth (P < .05). CONCLUSION These findings suggest that increased POLQ expression could serve as a valuable clinical marker and a potential therapeutic target in the treatment of thyroid cancer.
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Affiliation(s)
- C Corbin Frye
- Department of Surgery, Section of Surgical Oncology, Washington University School of Medicine, Saint Louis, MO.
| | - Lena Tennant
- Department of Surgery, Section of Surgical Oncology, Washington University School of Medicine, Saint Louis, MO
| | - Ashley Yeager
- Department of Surgery, Section of Surgical Oncology, Washington University School of Medicine, Saint Louis, MO
| | - Pedram Azimzadeh
- Department of Surgery, Section of Surgical Oncology, Washington University School of Medicine, Saint Louis, MO
| | - Priya Bhardwaj
- Department of Surgery, Section of Surgical Oncology, Washington University School of Medicine, Saint Louis, MO
| | - Yifei Xu
- Department of Surgery, Division of Public Health Sciences, Washington University School of Medicine, St. Louis, MO
| | - Jingxia Liu
- Department of Surgery, Division of Public Health Sciences, Washington University School of Medicine, St. Louis, MO
| | - Ghofran Othoum
- Department of Medicine, Division of Oncology, Washington University School of Medicine, Saint Louis, MO
| | - Christopher A Maher
- Department of Medicine, Division of Oncology, Washington University School of Medicine, Saint Louis, MO
| | - Rebecca Chernock
- Department of Pathology and Immunology, Division of Anatomic and Molecular Pathology, Washington University School of Medicine, Saint Louis, MO
| | - S Peter Goedegebuure
- Department of Surgery, Section of Surgical Oncology, Washington University School of Medicine, Saint Louis, MO
| | - William Gillanders
- Department of Surgery, Section of Surgical Oncology, Washington University School of Medicine, Saint Louis, MO
| | - John A Olson
- Department of Surgery, Section of Surgical Oncology, Washington University School of Medicine, Saint Louis, MO
| | - Taylor C Brown
- Department of Surgery, Section of Surgical Oncology, Washington University School of Medicine, Saint Louis, MO
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8
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Ito F, Li Z, Minakhin L, Khant HA, Pomerantz RT, Chen XS. Structural Basis for Polθ-Helicase DNA Binding and Microhomology-Mediated End-Joining. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.07.597860. [PMID: 38895274 PMCID: PMC11185775 DOI: 10.1101/2024.06.07.597860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
DNA double-strand breaks (DSBs) present a critical threat to genomic integrity, often precipitating genomic instability and oncogenesis. Repair of DSBs predominantly occurs through homologous recombination (HR) and non-homologous end joining (NHEJ). In HR-deficient cells, DNA polymerase theta (Polθ) becomes critical for DSB repair via microhomology-mediated end joining (MMEJ), also termed theta-mediated end joining (TMEJ). Thus, Polθ is synthetically lethal with BRCA1/2 and other HR factors, underscoring its potential as a therapeutic target in HR-deficient cancers. However, the molecular mechanisms governing Polθ-mediated MMEJ remain poorly understood. Here we present a series of cryo-electron microscopy structures of the Polθ helicase domain (Polθ-hel) in complex with DNA containing 3'-overhang. The structures reveal the sequential conformations adopted by Polθ-hel during the critical phases of DNA binding, microhomology searching, and microhomology annealing. The stepwise conformational changes within the Polθ-hel subdomains and its functional dimeric state are pivotal for aligning the 3'-overhangs, facilitating the microhomology search and subsequent annealing necessary for DSB repair via MMEJ. Our findings illustrate the essential molecular switches within Polθ-hel that orchestrate the MMEJ process in DSB repair, laying the groundwork for the development of targeted therapies against the Polθ-hel.
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Affiliation(s)
- Fumiaki Ito
- Molecular and Computational Biology, Department of Biological Sciences and Chemistry, University of Southern California, Los Angeles, California, 90089, USA
- Department of Microbiology, Immunology and Molecular Genetics
- California NanoSystems Institute, University of California, Los Angeles, CA90095, USA
| | - Ziyuan Li
- Molecular and Computational Biology, Department of Biological Sciences and Chemistry, University of Southern California, Los Angeles, California, 90089, USA
| | - Leonid Minakhin
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Htet A. Khant
- USC Center of Excellence for Nano-Imaging, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Richard T. Pomerantz
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Xiaojiang S. Chen
- Molecular and Computational Biology, Department of Biological Sciences and Chemistry, University of Southern California, Los Angeles, California, 90089, USA
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9
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Zhang H, Jiang L, Du X, Qian Z, Wu G, Jiang Y, Mao Z. The cGAS-Ku80 complex regulates the balance between two end joining subpathways. Cell Death Differ 2024; 31:792-803. [PMID: 38664591 PMCID: PMC11164703 DOI: 10.1038/s41418-024-01296-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 04/09/2024] [Accepted: 04/11/2024] [Indexed: 06/12/2024] Open
Abstract
As the major DNA sensor that activates the STING-TBK1 signaling cascade, cGAS is mainly present in the cytosol. A number of recent reports have indicated that cGAS also plays critical roles in the nucleus. Our previous work demonstrated for the first time that cGAS is translocated to the nucleus upon the occurrence of DNA damage and inhibits homologous recombination (HR), one of the two major pathways of DNA double strand break (DSB) repair. However, whether nuclear cGAS regulates the other DSB repair pathway, nonhomologous end joining (NHEJ), which can be further divided into the less error-prone canonical NHEJ (c-NHEJ) and more mutagenic alternative NHEJ (alt-NHEJ) subpathways, has not been characterized. Here, we demonstrated that cGAS tipped the balance of the two NHEJ subpathways toward c-NHEJ. Mechanistically, the cGAS-Ku80 complex enhanced the interaction between DNA-PKcs and the deubiquitinase USP7 to improve DNA-PKcs protein stability, thereby promoting c-NHEJ. In contrast, the cGAS-Ku80 complex suppressed alt-NHEJ by directly binding to the promoter of Polθ to suppress its transcription. Together, these findings reveal a novel function of nuclear cGAS in regulating DSB repair, suggesting that the presence of cGAS in the nucleus is also important in the maintenance of genome integrity.
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Affiliation(s)
- Haiping Zhang
- Shanghai Key Laboratory of Maternal Fetal Medicine, Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Lijun Jiang
- Shanghai Key Laboratory of Maternal Fetal Medicine, Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xinyi Du
- Department of Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Zhen Qian
- Shanghai Key Laboratory of Maternal Fetal Medicine, Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Guizhu Wu
- Department of Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, China.
| | - Ying Jiang
- Shanghai Key Laboratory of Maternal Fetal Medicine, Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China.
| | - Zhiyong Mao
- Shanghai Key Laboratory of Maternal Fetal Medicine, Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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10
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Thomas C, Avalos-Irving L, Victorino J, Green S, Andrews M, Rodrigues N, Ebirim S, Mudd A, Towle-Weicksel JB. Melanoma-Derived DNA Polymerase Theta Variants Exhibit Altered DNA Polymerase Activity. Biochemistry 2024; 63:1107-1117. [PMID: 38671548 PMCID: PMC11080051 DOI: 10.1021/acs.biochem.3c00670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 04/28/2024]
Abstract
DNA polymerase θ (Pol θ or POLQ) is primarily involved in repairing double-stranded breaks in DNA through an alternative pathway known as microhomology-mediated end joining (MMEJ) or theta-mediated end joining (TMEJ). Unlike other DNA repair polymerases, Pol θ is thought to be highly error-prone yet critical for cell survival. We have identified several POLQ gene variants from human melanoma tumors that experience altered DNA polymerase activity, including a propensity for incorrect nucleotide selection and reduced polymerization rates compared to WT Pol θ. Variants are 30-fold less efficient at incorporating a nucleotide during repair and up to 70-fold less accurate at selecting the correct nucleotide opposite a templating base. This suggests that aberrant Pol θ has reduced DNA repair capabilities and may also contribute to increased mutagenesis. Moreover, the variants were identified in established tumors, suggesting that cancer cells may use mutated polymerases to promote metastasis and drug resistance.
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Affiliation(s)
- Corey Thomas
- Department of Physical Sciences, Rhode Island College, 600 Mount Pleasant Avenue, Providence, Rhode Island 02908, United States
| | - Lisbeth Avalos-Irving
- Department of Physical Sciences, Rhode Island College, 600 Mount Pleasant Avenue, Providence, Rhode Island 02908, United States
| | - Jorge Victorino
- Department of Physical Sciences, Rhode Island College, 600 Mount Pleasant Avenue, Providence, Rhode Island 02908, United States
| | - Sydney Green
- Department of Physical Sciences, Rhode Island College, 600 Mount Pleasant Avenue, Providence, Rhode Island 02908, United States
| | - Morgan Andrews
- Department of Physical Sciences, Rhode Island College, 600 Mount Pleasant Avenue, Providence, Rhode Island 02908, United States
| | - Naisha Rodrigues
- Department of Physical Sciences, Rhode Island College, 600 Mount Pleasant Avenue, Providence, Rhode Island 02908, United States
| | - Sarah Ebirim
- Department of Physical Sciences, Rhode Island College, 600 Mount Pleasant Avenue, Providence, Rhode Island 02908, United States
| | - Ayden Mudd
- Department of Physical Sciences, Rhode Island College, 600 Mount Pleasant Avenue, Providence, Rhode Island 02908, United States
| | - Jamie B. Towle-Weicksel
- Department of Physical Sciences, Rhode Island College, 600 Mount Pleasant Avenue, Providence, Rhode Island 02908, United States
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11
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Zerio CJ, Bai Y, Sosa-Alvarado BA, Guzi T, Lander GC. Human polymerase theta helicase positions DNA microhomologies for double-strand break repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.26.591388. [PMID: 38712090 PMCID: PMC11071473 DOI: 10.1101/2024.04.26.591388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
DNA double-strand breaks occur in all human cells on a daily basis and must be repaired with high fidelity to minimize genomic instability1. Deficiencies in high-fidelity DNA repair by homologous recombination lead to dependence on DNA polymerase theta, which identifies DNA microhomologies in 3' single-stranded DNA overhangs and anneals them to initiate error-prone double-strand break repair. The resulting genomic instability is associated with numerous cancers, thereby making this polymerase an attractive therapeutic target2,3. However, despite the biomedical importance of polymerase theta, the molecular details of how it initiates DNA break repair remain unclear4,5. Here we present cryo-electron microscopy structures of the polymerase theta helicase domain bound to microhomology-containing DNA, revealing DNA-induced rearrangements of the helicase that enable DNA repair. Our structures show that DNA-bound helicase dimers facilitate a microhomology search that positions 3' single-stranded DNA ends in proximity to align complementary base pairs and anneal DNA microhomology. We define the molecular determinants that enable the polymerase theta helicase domain to identify and pair DNA microhomologies to initiate mutagenic DNA repair, providing mechanistic insights into therapeutic targeting of these interactions.
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Affiliation(s)
- Christopher J. Zerio
- Department of Integrative Structural and Computational Biology, Scripps Research; La Jolla, CA, USA
| | | | | | | | - Gabriel C. Lander
- Department of Integrative Structural and Computational Biology, Scripps Research; La Jolla, CA, USA
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12
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Fijen C, Drogalis Beckham L, Terino D, Li Y, Ramsden DA, Wood RD, Doublié S, Rothenberg E. Sequential requirements for distinct Polθ domains during theta-mediated end joining. Mol Cell 2024; 84:1460-1474.e6. [PMID: 38640894 PMCID: PMC11031631 DOI: 10.1016/j.molcel.2024.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 01/10/2024] [Accepted: 03/12/2024] [Indexed: 04/21/2024]
Abstract
DNA polymerase θ (Polθ) plays a central role in a DNA double-strand break repair pathway termed theta-mediated end joining (TMEJ). TMEJ functions by pairing short-sequence "microhomologies" (MHs) in single-stranded DNA at each end of a break and subsequently initiating DNA synthesis. It is not known how the Polθ helicase domain (HD) and polymerase domain (PD) operate to bring together MHs and facilitate repair. To resolve these transient processes in real time, we utilized in vitro single-molecule FRET approaches and biochemical analyses. We find that the Polθ-HD mediates the initial capture of two ssDNA strands, bringing them in close proximity. The Polθ-PD binds and stabilizes pre-annealed MHs to form a synaptic complex (SC) and initiate repair synthesis. Individual synthesis reactions show that Polθ is inherently non-processive, accounting for complex mutational patterns during TMEJ. Binding of Polθ-PD to stem-loop-forming sequences can substantially limit synapsis, depending on the available dNTPs and sequence context.
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Affiliation(s)
- Carel Fijen
- Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA.
| | - Lea Drogalis Beckham
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
| | - Dante Terino
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Yuzhen Li
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77230, USA
| | - Dale A Ramsden
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Richard D Wood
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77230, USA
| | - Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA.
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13
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Fried W, Tyagi M, Minakhin L, Chandramouly G, Tredinnick T, Ramanjulu M, Auerbacher W, Calbert M, Rusanov T, Hoang T, Borisonnik N, Betsch R, Krais JJ, Wang Y, Vekariya UM, Gordon J, Morton G, Kent T, Skorski T, Johnson N, Childers W, Chen XS, Pomerantz RT. Discovery of a small-molecule inhibitor that traps Polθ on DNA and synergizes with PARP inhibitors. Nat Commun 2024; 15:2862. [PMID: 38580648 PMCID: PMC10997755 DOI: 10.1038/s41467-024-46593-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 03/04/2024] [Indexed: 04/07/2024] Open
Abstract
The DNA damage response (DDR) protein DNA Polymerase θ (Polθ) is synthetic lethal with homologous recombination (HR) factors and is therefore a promising drug target in BRCA1/2 mutant cancers. We discover an allosteric Polθ inhibitor (Polθi) class with 4-6 nM IC50 that selectively kills HR-deficient cells and acts synergistically with PARP inhibitors (PARPi) in multiple genetic backgrounds. X-ray crystallography and biochemistry reveal that Polθi selectively inhibits Polθ polymerase (Polθ-pol) in the closed conformation on B-form DNA/DNA via an induced fit mechanism. In contrast, Polθi fails to inhibit Polθ-pol catalytic activity on A-form DNA/RNA in which the enzyme binds in the open configuration. Remarkably, Polθi binding to the Polθ-pol:DNA/DNA closed complex traps the polymerase on DNA for more than forty minutes which elucidates the inhibitory mechanism of action. These data reveal a unique small-molecule DNA polymerase:DNA trapping mechanism that induces synthetic lethality in HR-deficient cells and potentiates the activity of PARPi.
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Affiliation(s)
- William Fried
- Molecular and Computational Biology, Department of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Mrityunjay Tyagi
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Leonid Minakhin
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Gurushankar Chandramouly
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Taylor Tredinnick
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Mercy Ramanjulu
- Recombination Therapeutics, Pennsylvania Biotechnology Center, Doylestown, PA, 18902, USA
| | - William Auerbacher
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Marissa Calbert
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
- Fels Cancer Institute for Personalized Medicine, Philadelphia, PA, USA
| | - Timur Rusanov
- Department of Pharmacology and Regenerative Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | | | | | - Robert Betsch
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - John J Krais
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Yifan Wang
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Umeshkumar M Vekariya
- Fels Cancer Institute for Personalized Medicine, Philadelphia, PA, USA
- Department of Cancer and Cellular Biology, Temple University Lewis Katz School of Medicine, Philadelphia, PA, USA
| | - John Gordon
- Fels Cancer Institute for Personalized Medicine, Philadelphia, PA, USA
| | - George Morton
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, PA, USA
| | - Tatiana Kent
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Tomasz Skorski
- Fels Cancer Institute for Personalized Medicine, Philadelphia, PA, USA
- Department of Cancer and Cellular Biology, Temple University Lewis Katz School of Medicine, Philadelphia, PA, USA
| | - Neil Johnson
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Wayne Childers
- Recombination Therapeutics, Pennsylvania Biotechnology Center, Doylestown, PA, 18902, USA
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, PA, USA
| | - Xiaojiang S Chen
- Molecular and Computational Biology, Department of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA, USA
- Recombination Therapeutics, Pennsylvania Biotechnology Center, Doylestown, PA, 18902, USA
| | - Richard T Pomerantz
- Department of Biochemistry and Molecular Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA.
- Recombination Therapeutics, Pennsylvania Biotechnology Center, Doylestown, PA, 18902, USA.
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14
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Singh M, Raseley K, Perez AM, MacKenzie D, Kosiyatrakul ST, Desai S, Batista N, Guru N, Loomba KK, Abid HZ, Wang Y, Udo-Bellner L, Stout RF, Schildkraut CL, Xiao M, Zhang D. Elucidation of the molecular mechanism of the breakage-fusion-bridge (BFB) cycle using a CRISPR-dCas9 cellular model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.03.587951. [PMID: 38617299 PMCID: PMC11014597 DOI: 10.1101/2024.04.03.587951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Chromosome instability (CIN) is frequently observed in many tumors. The breakage-fusion-bridge (BFB) cycle has been proposed to be one of the main drivers of CIN during tumorigenesis and tumor evolution. However, the detailed mechanisms for the individual steps of the BFB cycle warrants further investigation. Here, we demonstrated that a nuclease-dead Cas9 (dCas9) coupled with a telomere-specific single-guide RNA (sgTelo) can be used to model the BFB cycle. First, we showed that targeting dCas9 to telomeres using sgTelo impeded DNA replication at telomeres and induced a pronounced increase of replication stress and DNA damage. Using Single-Molecule Telomere Assay via Optical Mapping (SMTA-OM), we investigated the genome-wide features of telomeres in the dCas9/sgTelo cells and observed a dramatic increase of chromosome end fusions, including fusion/ITS+ and fusion/ITS-.Consistently, we also observed an increase in the formation of dicentric chromosomes, anaphase bridges, and intercellular telomeric chromosome bridges (ITCBs). Utilizing the dCas9/sgTelo system, we uncovered many novel molecular and structural features of the ITCB and demonstrated that multiple DNA repair pathways are implicated in the formation of ITCBs. Our studies shed new light on the molecular mechanisms of the BFB cycle, which will advance our understanding of tumorigenesis, tumor evolution, and drug resistance.
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15
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Kannan S, Gillespie SW, Picking WL, Picking WD, Lorson CL, Singh K. Inhibitors against DNA Polymerase I Family of Enzymes: Novel Targets and Opportunities. BIOLOGY 2024; 13:204. [PMID: 38666816 PMCID: PMC11048162 DOI: 10.3390/biology13040204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 03/18/2024] [Accepted: 03/20/2024] [Indexed: 04/28/2024]
Abstract
DNA polymerases replicate cellular genomes and/or participate in the maintenance of genome integrity. DNA polymerases sharing high sequence homology with E. coli DNA polymerase I (pol I) have been grouped in Family A. Pol I participates in Okazaki fragment maturation and in bacterial genome repair. Since its discovery in 1956, pol I has been extensively studied, primarily to gain deeper insights into the mechanism of DNA replication. As research on DNA polymerases advances, many novel functions of this group of polymerases are being uncovered. For example, human DNA polymerase θ (a Family A DNA pol) has been shown to synthesize DNA using RNA as a template, a function typically attributed to retroviral reverse transcriptase. Increased interest in drug discovery against pol θ has emerged due to its roles in cancer. Likewise, Pol I family enzymes also appear attractive as drug-development targets against microbial infections. Development of antimalarial compounds targeting apicoplast apPOL, an ortholog of Pol I, further extends the targeting of this family of enzymes. Here, we summarize reported drug-development efforts against Family A polymerases and future perspective regarding these enzymes as antibiotic targets. Recently developed techniques, such as artificial intelligence, can be used to facilitate the development of new drugs.
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Affiliation(s)
- Saathvik Kannan
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; (S.K.); (S.W.G.); (W.L.P.); (W.D.P.); (C.L.L.)
| | - Samuel W. Gillespie
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; (S.K.); (S.W.G.); (W.L.P.); (W.D.P.); (C.L.L.)
| | - Wendy L. Picking
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; (S.K.); (S.W.G.); (W.L.P.); (W.D.P.); (C.L.L.)
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
| | - William D. Picking
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; (S.K.); (S.W.G.); (W.L.P.); (W.D.P.); (C.L.L.)
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
| | - Christian L. Lorson
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; (S.K.); (S.W.G.); (W.L.P.); (W.D.P.); (C.L.L.)
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
| | - Kamal Singh
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; (S.K.); (S.W.G.); (W.L.P.); (W.D.P.); (C.L.L.)
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
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16
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Yu Y, Wang X, Fox J, Li Q, Yu Y, Hastings PJ, Chen K, Ira G. RPA and Rad27 limit templated and inverted insertions at DNA breaks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.07.583931. [PMID: 38496432 PMCID: PMC10942419 DOI: 10.1101/2024.03.07.583931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Formation of templated insertions at DNA double-strand breaks (DSBs) is very common in cancer cells. The mechanisms and enzymes regulating these events are largely unknown. Here, we investigated templated insertions in yeast at DSBs using amplicon sequencing across a repaired locus. We document very short (most ∼5-34 bp), templated inverted duplications at DSBs. They are generated through a foldback mechanism that utilizes microhomologies adjacent to the DSB. Enzymatic requirements suggest a hybrid mechanism wherein one end requires Polδ-mediated synthesis while the other end is captured by nonhomologous end joining (NHEJ). This process is exacerbated in mutants with low levels or mutated RPA ( rtt105 Δ; rfa1 -t33) or extensive resection mutant ( sgs1 Δ exo1 Δ). Templated insertions from various distant genomic locations also increase in these mutants as well as in rad27 Δ and originate from fragile regions of the genome. Among complex insertions, common events are insertions of two sequences, originating from the same locus and with inverted orientation. We propose that these inversions are also formed by microhomology-mediated template switching. Taken together, we propose that a shortage of RPA typical in cancer cells is one possible factor stimulating the formation of templated insertions.
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17
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van de Kooij B, Schreuder A, Pavani R, Garzero V, Uruci S, Wendel TJ, van Hoeck A, San Martin Alonso M, Everts M, Koerse D, Callen E, Boom J, Mei H, Cuppen E, Luijsterburg MS, van Vugt MATM, Nussenzweig A, van Attikum H, Noordermeer SM. EXO1 protects BRCA1-deficient cells against toxic DNA lesions. Mol Cell 2024; 84:659-674.e7. [PMID: 38266640 DOI: 10.1016/j.molcel.2023.12.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 10/14/2023] [Accepted: 12/22/2023] [Indexed: 01/26/2024]
Abstract
Inactivating mutations in the BRCA1 and BRCA2 genes impair DNA double-strand break (DSB) repair by homologous recombination (HR), leading to chromosomal instability and cancer. Importantly, BRCA1/2 deficiency also causes therapeutically targetable vulnerabilities. Here, we identify the dependency on the end resection factor EXO1 as a key vulnerability of BRCA1-deficient cells. EXO1 deficiency generates poly(ADP-ribose)-decorated DNA lesions during S phase that associate with unresolved DSBs and genomic instability in BRCA1-deficient but not in wild-type or BRCA2-deficient cells. Our data indicate that BRCA1/EXO1 double-deficient cells accumulate DSBs due to impaired repair by single-strand annealing (SSA) on top of their HR defect. In contrast, BRCA2-deficient cells retain SSA activity in the absence of EXO1 and hence tolerate EXO1 loss. Consistent with a dependency on EXO1-mediated SSA, we find that BRCA1-mutated tumors show elevated EXO1 expression and increased SSA-associated genomic scars compared with BRCA1-proficient tumors. Overall, our findings uncover EXO1 as a promising therapeutic target for BRCA1-deficient tumors.
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Affiliation(s)
- Bert van de Kooij
- Department of Human Genetics, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands; Department of Medical Oncology, University Medical Center Groningen, Groningen 9713 GZ, the Netherlands
| | - Anne Schreuder
- Department of Human Genetics, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands; Oncode Institute, Utrecht 3521 AL, the Netherlands
| | - Raphael Pavani
- Laboratory of Genome Integrity, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Veronica Garzero
- Department of Human Genetics, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands; Oncode Institute, Utrecht 3521 AL, the Netherlands
| | - Sidrit Uruci
- Department of Human Genetics, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands
| | - Tiemen J Wendel
- Department of Human Genetics, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands; Oncode Institute, Utrecht 3521 AL, the Netherlands
| | - Arne van Hoeck
- Oncode Institute, Utrecht 3521 AL, the Netherlands; Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht 3584 CG, the Netherlands
| | - Marta San Martin Alonso
- Department of Human Genetics, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands; Oncode Institute, Utrecht 3521 AL, the Netherlands
| | - Marieke Everts
- Department of Medical Oncology, University Medical Center Groningen, Groningen 9713 GZ, the Netherlands
| | - Dana Koerse
- Department of Human Genetics, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands
| | - Elsa Callen
- Laboratory of Genome Integrity, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jasper Boom
- Sequencing Analysis Support Core, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands
| | - Hailiang Mei
- Sequencing Analysis Support Core, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands
| | - Edwin Cuppen
- Oncode Institute, Utrecht 3521 AL, the Netherlands; Centre for Molecular Medicine, University Medical Centre Utrecht, Utrecht 3584 CG, the Netherlands; Hartwig Medical Foundation, Amsterdam 1098 XH, the Netherlands
| | - Martijn S Luijsterburg
- Department of Human Genetics, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands
| | - Marcel A T M van Vugt
- Department of Medical Oncology, University Medical Center Groningen, Groningen 9713 GZ, the Netherlands
| | - André Nussenzweig
- Laboratory of Genome Integrity, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Haico van Attikum
- Department of Human Genetics, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands.
| | - Sylvie M Noordermeer
- Department of Human Genetics, Leiden University Medical Centre, Leiden 2333 ZC, the Netherlands; Oncode Institute, Utrecht 3521 AL, the Netherlands.
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18
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Biller M, Kabir S, Boado C, Nipper S, Saffa A, Tal A, Allen S, Sasanuma H, Dréau D, Vaziri C, Tomida J. REV7-p53 interaction inhibits ATM-mediated DNA damage signaling. Cell Cycle 2024; 23:339-352. [PMID: 38557443 PMCID: PMC11174130 DOI: 10.1080/15384101.2024.2333227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 03/18/2024] [Indexed: 04/04/2024] Open
Abstract
REV7 is an abundant, multifunctional protein that is a known factor in cell cycle regulation and in several key DNA repair pathways including Trans-Lesion Synthesis (TLS), the Fanconi Anemia (FA) pathway, and DNA Double-Strand Break (DSB) repair pathway choice. Thus far, no direct role has been studied for REV7 in the DNA damage response (DDR) signaling pathway. Here we describe a novel function for REV7 in DSB-induced p53 signaling. We show that REV7 binds directly to p53 to block ATM-dependent p53 Ser15 phosphorylation. We also report that REV7 is involved in the destabilization of p53. These findings affirm REV7's participation in fundamental cell cycle and DNA repair pathways. Furthermore, they highlight REV7 as a critical factor for the integration of multiple processes that determine viability and genome stability.
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Affiliation(s)
- Megan Biller
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Sara Kabir
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Chkylle Boado
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Sarah Nipper
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Alexandra Saffa
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Ariella Tal
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Sydney Allen
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Hiroyuki Sasanuma
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Didier Dréau
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Cyrus Vaziri
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA
| | - Junya Tomida
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, USA
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19
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Chanchal DK, Chaudhary JS, Kumar P, Agnihotri N, Porwal P. CRISPR-Based Therapies: Revolutionizing Drug Development and Precision Medicine. Curr Gene Ther 2024; 24:193-207. [PMID: 38310456 DOI: 10.2174/0115665232275754231204072320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/26/2023] [Accepted: 11/15/2023] [Indexed: 02/05/2024]
Abstract
With the discovery of CRISPR-Cas9, drug development and precision medicine have undergone a major change. This review article looks at the new ways that CRISPR-based therapies are being used and how they are changing the way medicine is done. CRISPR technology's ability to precisely and flexibly edit genes has opened up new ways to find, validate, and develop drug targets. Also, it has made way for personalized gene therapies, precise gene editing, and advanced screening techniques, all of which hold great promise for treating a wide range of diseases. In this article, we look at the latest research and clinical trials that show how CRISPR could be used to treat genetic diseases, cancer, infectious diseases, and other hard-to-treat conditions. However, ethical issues and problems with regulations are also discussed in relation to CRISPR-based therapies, which shows how important it is to use them safely and responsibly. As CRISPR continues to change how drugs are made and used, this review shines a light on the amazing things that have been done and what the future might hold in this rapidly changing field.
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Affiliation(s)
- Dilip Kumar Chanchal
- Department of Pharmacy, Smt. Vidyawati College of Pharmacy, Jhansi, Uttar Pradesh, India
- Glocal School of Pharmacy, Glocal University Mirzapur Pole, Saharanpur - 247121, Uttar Pradesh, India
| | | | - Pushpendra Kumar
- Faculty of Pharmacy, Uttar Pradesh University of Medical Sciences, Saifai, Etawah 206130, Uttar Pradesh, India
| | - Neha Agnihotri
- Department of Pharmacy, Maharana Pratap College of Pharmacy, Kothi, Mandhana, Kanpur-209217, Uttar Pradesh, India
| | - Prateek Porwal
- Glocal School of Pharmacy, Glocal University Mirzapur Pole, Saharanpur - 247121, Uttar Pradesh, India
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20
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Yueh WT, Glass DJ, Johnson N. Brca1 Mouse Models: Functional Insights and Therapeutic Opportunities. J Mol Biol 2024; 436:168372. [PMID: 37979908 PMCID: PMC10882579 DOI: 10.1016/j.jmb.2023.168372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 11/08/2023] [Accepted: 11/14/2023] [Indexed: 11/20/2023]
Abstract
Brca1 mouse models were first reported in the mid-1990's shortly after cloning the human gene. Since then, many mouse models with a range of mutations have been generated, some mimic patient mutations, others are designed to probe specific protein domains and functions. In this review, we discuss early and recent studies using engineered Brca1 mouse alleles, and their implications for understanding Brca1 protein function in the context of DNA repair, tumorigenesis, and anti-cancer therapeutics.
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Affiliation(s)
- Wei-Ting Yueh
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - David J Glass
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Neil Johnson
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
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21
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Krais JJ, Glass DJ, Chudoba I, Wang Y, Feng W, Simpson D, Patel P, Liu Z, Neumann-Domer R, Betsch RG, Bernhardy AJ, Bradbury AM, Conger J, Yueh WT, Nacson J, Pomerantz RT, Gupta GP, Testa JR, Johnson N. Genetic separation of Brca1 functions reveal mutation-dependent Polθ vulnerabilities. Nat Commun 2023; 14:7714. [PMID: 38001070 PMCID: PMC10673838 DOI: 10.1038/s41467-023-43446-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 11/09/2023] [Indexed: 11/26/2023] Open
Abstract
Homologous recombination (HR)-deficiency induces a dependency on DNA polymerase theta (Polθ/Polq)-mediated end joining, and Polθ inhibitors (Polθi) are in development for cancer therapy. BRCA1 and BRCA2 deficient cells are thought to be synthetic lethal with Polθ, but whether distinct HR gene mutations give rise to equivalent Polθ-dependence, and the events that drive lethality, are unclear. In this study, we utilized mouse models with separate Brca1 functional defects to mechanistically define Brca1-Polθ synthetic lethality. Surprisingly, homozygous Brca1 mutant, Polq-/- cells were viable, but grew slowly and had chromosomal instability. Brca1 mutant cells proficient in DNA end resection were significantly more dependent on Polθ for viability; here, treatment with Polθi elevated RPA foci, which persisted through mitosis. In an isogenic system, BRCA1 null cells were defective, but PALB2 and BRCA2 mutant cells exhibited active resection, and consequently stronger sensitivity to Polθi. Thus, DNA end resection is a critical determinant of Polθi sensitivity in HR-deficient cells, and should be considered when selecting patients for clinical studies.
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Affiliation(s)
- John J Krais
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA.
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - David J Glass
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
- Temple University, Lewis Katz School of Medicine, Philadelphia, PA, 19140, USA
| | - Ilse Chudoba
- MetaSystems Probes, GmbH, Industriestr, 68804, Altlussheim, Germany
| | - Yifan Wang
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Wanjuan Feng
- Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Dennis Simpson
- Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Pooja Patel
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Zemin Liu
- Cytogenetics Laboratory, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Ryan Neumann-Domer
- Cytogenetics Laboratory, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Robert G Betsch
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Andrea J Bernhardy
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Alice M Bradbury
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Jason Conger
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Wei-Ting Yueh
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Joseph Nacson
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Richard T Pomerantz
- Thomas Jefferson University, Sidney Kimmel Cancer Center, Department of Biochemistry and Molecular Biology, Philadelphia, PA, 19107, USA
| | - Gaorav P Gupta
- Cancer Control and Prevention Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Joseph R Testa
- Cytogenetics Laboratory, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
- Cancer Control and Prevention Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA
| | - Neil Johnson
- Nuclear Dynamics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, USA.
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22
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Thomas C, Avalos-Irving L, Victorino J, Green S, Andrews M, Rodrigues N, Ebirim S, Mudd A, Towle-Weicksel JB. Melanoma-derived DNA polymerase theta variants exhibit altered DNA polymerase activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.566933. [PMID: 38014040 PMCID: PMC10680777 DOI: 10.1101/2023.11.14.566933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
DNA Polymerase θ (Pol θ or POLQ) is primarily involved in repairing double-stranded breaks in DNA through the alternative pathway known as microhomology-mediated end joining (MMEJ) or theta-mediated end joining (TMEJ). Unlike other DNA repair polymerases, Pol θ is thought to be highly error prone, yet critical for cell survival. We have identified several mutations in the POLQ gene from human melanoma tumors. Through biochemical analysis, we have demonstrated that all three cancer-associated variants experienced altered DNA polymerase activity including a propensity for incorrect nucleotide selection and reduced polymerization rates compared to WT Pol θ. Moreover, the variants are 30 fold less efficient at incorporating a nucleotide during repair and up to 70 fold less accurate at selecting the correct nucleotide opposite a templating base. Taken together, this suggests that aberrant Pol θ has reduced DNA repair capabilities and may also contribute to increased mutagenesis. While this may be beneficial to normal cell survival, the variants were identified in established tumors suggesting that cancer cells may use this promiscuous polymerase to its advantage to promote metastasis and drug resistance.
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23
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Stroik S, Carvajal-Garcia J, Gupta D, Edwards A, Luthman A, Wyatt DW, Dannenberg RL, Feng W, Kunkel TA, Gupta GP, Hedglin M, Wood R, Doublié S, Rothenberg E, Ramsden DA. Stepwise requirements for polymerases δ and θ in theta-mediated end joining. Nature 2023; 623:836-841. [PMID: 37968395 PMCID: PMC10959172 DOI: 10.1038/s41586-023-06729-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 10/06/2023] [Indexed: 11/17/2023]
Abstract
Timely repair of chromosomal double-strand breaks is required for genome integrity and cellular viability. The polymerase theta-mediated end joining pathway has an important role in resolving these breaks and is essential in cancers defective in other DNA repair pathways, thus making it an emerging therapeutic target1. It requires annealing of 2-6 nucleotides of complementary sequence, microhomologies, that are adjacent to the broken ends, followed by initiation of end-bridging DNA synthesis by polymerase θ. However, the other pathway steps remain inadequately defined, and the enzymes required for them are unknown. Here we demonstrate requirements for exonucleolytic digestion of unpaired 3' tails before polymerase θ can initiate synthesis, then a switch to a more accurate, processive and strand-displacing polymerase to complete repair. We show the replicative polymerase, polymerase δ, is required for both steps; its 3' to 5' exonuclease activity for flap trimming, then its polymerase activity for extension and completion of repair. The enzymatic steps that are essential and specific to this pathway are mediated by two separate, sequential engagements of the two polymerases. The requisite coupling of these steps together is likely to be facilitated by physical association of the two polymerases. This pairing of polymerase δ with a polymerase capable of end-bridging synthesis, polymerase θ, may help to explain why the normally high-fidelity polymerase δ participates in genome destabilizing processes such as mitotic DNA synthesis2 and microhomology-mediated break-induced replication3.
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Affiliation(s)
- Susanna Stroik
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Dipika Gupta
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Alyssa Edwards
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Adam Luthman
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - David W Wyatt
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Rachel L Dannenberg
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
| | - Wanjuan Feng
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Thomas A Kunkel
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Gaorav P Gupta
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mark Hedglin
- Department of Chemistry, The Pennsylvania State University, University Park, PA, USA
| | - Richard Wood
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center and The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Dale A Ramsden
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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24
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Mangalhara KC, Varanasi SK, Johnson MA, Burns MJ, Rojas GR, Moltó PBE, Sainz AG, Tadepalle N, Abbott KL, Mendiratta G, Chen D, Farsakoglu Y, Kunchok T, Hoffmann FA, Parisi B, Rincon M, Heiden MGV, Bosenberg M, Hargreaves DC, Kaech SM, Shadel GS. Manipulating mitochondrial electron flow enhances tumor immunogenicity. Science 2023; 381:1316-1323. [PMID: 37733872 PMCID: PMC11034774 DOI: 10.1126/science.abq1053] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 08/02/2023] [Indexed: 09/23/2023]
Abstract
Although tumor growth requires the mitochondrial electron transport chain (ETC), the relative contribution of complex I (CI) and complex II (CII), the gatekeepers for initiating electron flow, remains unclear. In this work, we report that the loss of CII, but not that of CI, reduces melanoma tumor growth by increasing antigen presentation and T cell-mediated killing. This is driven by succinate-mediated transcriptional and epigenetic activation of major histocompatibility complex-antigen processing and presentation (MHC-APP) genes independent of interferon signaling. Furthermore, knockout of methylation-controlled J protein (MCJ), to promote electron entry preferentially through CI, provides proof of concept of ETC rewiring to achieve antitumor responses without side effects associated with an overall reduction in mitochondrial respiration in noncancer cells. Our results may hold therapeutic potential for tumors that have reduced MHC-APP expression, a common mechanism of cancer immunoevasion.
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Affiliation(s)
| | | | | | - Mannix J. Burns
- Salk Institute for Biological Studies; La Jolla, CA 92037, USA
| | - Gladys R. Rojas
- Salk Institute for Biological Studies; La Jolla, CA 92037, USA
| | | | - Alva G. Sainz
- Salk Institute for Biological Studies; La Jolla, CA 92037, USA
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06520, USA
| | | | - Keene L. Abbott
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Gaurav Mendiratta
- Salk Institute for Biological Studies; La Jolla, CA 92037, USA
- Current address: Takeda Development Center America, San Diego, CA 92121, USA
| | - Dan Chen
- Salk Institute for Biological Studies; La Jolla, CA 92037, USA
| | | | - Tenzin Kunchok
- Whitehead Institute Metabolomics Core Facility, Cambridge, MA 02139, USA
| | | | - Bianca Parisi
- Salk Institute for Biological Studies; La Jolla, CA 92037, USA
| | - Mercedes Rincon
- Department of Immunology and Microbiology, University of Colorado Denver; Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Matthew G. Vander Heiden
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Marcus Bosenberg
- Departments of Pathology, Dermatology and Immunology, Yale University School of Medicine New Haven, CT 06520, USA
| | | | - Susan M. Kaech
- Salk Institute for Biological Studies; La Jolla, CA 92037, USA
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25
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Gelot C, Kovacs MT, Miron S, Mylne E, Haan A, Boeffard-Dosierre L, Ghouil R, Popova T, Dingli F, Loew D, Guirouilh-Barbat J, Del Nery E, Zinn-Justin S, Ceccaldi R. Polθ is phosphorylated by PLK1 to repair double-strand breaks in mitosis. Nature 2023; 621:415-422. [PMID: 37674080 PMCID: PMC10499603 DOI: 10.1038/s41586-023-06506-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 08/01/2023] [Indexed: 09/08/2023]
Abstract
DNA double-strand breaks (DSBs) are deleterious lesions that challenge genome integrity. To mitigate this threat, human cells rely on the activity of multiple DNA repair machineries that are tightly regulated throughout the cell cycle1. In interphase, DSBs are mainly repaired by non-homologous end joining and homologous recombination2. However, these pathways are completely inhibited in mitosis3-5, leaving the fate of mitotic DSBs unknown. Here we show that DNA polymerase theta6 (Polθ) repairs mitotic DSBs and thereby maintains genome integrity. In contrast to other DSB repair factors, Polθ function is activated in mitosis upon phosphorylation by Polo-like kinase 1 (PLK1). Phosphorylated Polθ is recruited by a direct interaction with the BRCA1 C-terminal domains of TOPBP1 to mitotic DSBs, where it mediates joining of broken DNA ends. Loss of Polθ leads to defective repair of mitotic DSBs, resulting in a loss of genome integrity. This is further exacerbated in cells that are deficient in homologous recombination, where loss of mitotic DSB repair by Polθ results in cell death. Our results identify mitotic DSB repair as the underlying cause of synthetic lethality between Polθ and homologous recombination. Together, our findings reveal the critical importance of mitotic DSB repair in the maintenance of genome integrity.
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Affiliation(s)
- Camille Gelot
- INSERM U830, PSL Research University, Institut Curie, Paris, France
| | | | - Simona Miron
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Paris-Saclay University, Gif-sur-Yvette, France
| | - Emilie Mylne
- INSERM U830, PSL Research University, Institut Curie, Paris, France
| | - Alexis Haan
- INSERM U830, PSL Research University, Institut Curie, Paris, France
| | - Liza Boeffard-Dosierre
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Paris-Saclay University, Gif-sur-Yvette, France
| | - Rania Ghouil
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Paris-Saclay University, Gif-sur-Yvette, France
| | - Tatiana Popova
- INSERM U830, DNA Repair and Uveal Melanoma (D.R.U.M.), Equipe labellisée par la Ligue Nationale Contre le Cancer, PSL Research University, Institut Curie, Paris, France
| | - Florent Dingli
- CurieCoreTech Mass Spectrometry Proteomics, Institut Curie, PSL Research University, Paris, France
| | - Damarys Loew
- CurieCoreTech Mass Spectrometry Proteomics, Institut Curie, PSL Research University, Paris, France
| | - Josée Guirouilh-Barbat
- Université de Paris, INSERM U1016, UMR 8104 CNRS, Equipe Labellisée Ligue Nationale Contre le Cancer, Institut Cochin, Paris, France
| | - Elaine Del Nery
- Department of Translational Research-Biophenics High-Content Screening Laboratory, Cell and Tissue Imaging Facility (PICT-IBiSA), PSL Research University, Institut Curie, Paris, France
| | - Sophie Zinn-Justin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Paris-Saclay University, Gif-sur-Yvette, France
| | - Raphael Ceccaldi
- INSERM U830, PSL Research University, Institut Curie, Paris, France.
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26
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Jiang F, Wang L, Dong Y, Nie W, Zhou H, Gao J, Zheng P. DPPA5A suppresses the mutagenic TLS and MMEJ pathways by modulating the cryptic splicing of Rev1 and Polq in mouse embryonic stem cells. Proc Natl Acad Sci U S A 2023; 120:e2305187120. [PMID: 37459543 PMCID: PMC10372678 DOI: 10.1073/pnas.2305187120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 06/13/2023] [Indexed: 07/20/2023] Open
Abstract
Genetic alterations are often acquired during prolonged propagation of pluripotent stem cells (PSCs). This ruins the stem cell quality and hampers their full applications. Understanding how PSCs maintain genomic integrity would provide the clues to overcome the hurdle. It has been known that embryonic stem cells (ESCs) utilize high-fidelity pathways to ensure genomic stability, but the underlying mechanisms remain largely elusive. Here, we show that many DNA damage response and repair genes display differential alternative splicing in mouse ESCs compared to differentiated cells. Particularly, Rev1 and Polq, two key genes for mutagenic translesion DNA synthesis (TLS) and microhomology-mediated end joining (MMEJ) repair pathways, respectively, display a significantly higher rate of cryptic exon (CE) inclusion in ESCs. The frequent CE inclusion disrupts the normal protein expressions of REV1 and POLθ, thereby suppressing the mutagenic TLS and MMEJ. Further, we identify an ESC-specific RNA binding protein DPPA5A which stimulates the CE inclusion in Rev1 and Polq. Depletion of DPPA5A in mouse ESCs decreased the CE inclusion of Rev1 and Polq, induced the protein expression, and stimulated the TLS and MMEJ activity. Enforced expression of DPPA5A in NIH3T3 cells displayed reverse effects. Mechanistically, we found that DPPA5A directly regulated CE splicing of Rev1. DPPA5A associates with U2 small nuclear ribonucleoprotein of the spliceosome and binds to the GA-rich motif in the CE of Rev1 to promote CE inclusion. Thus, our study uncovers a mechanism to suppress mutagenic TLS and MMEJ pathways in ESCs.
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Affiliation(s)
- Fangjie Jiang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan650223, China
- University of Chinese Academy of Sciences, Beijing101408, China
- Department of Reproductive Medicine, The Second Affiliated Hospital of Kunming Medical University,Kunming650101, China
| | - Lin Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan650223, China
- Key Laboratory of Animal Models and Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan650223, China
| | - Yuping Dong
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan650223, China
- University of Chinese Academy of Sciences, Beijing101408, China
- Key Laboratory of Animal Models and Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan650223, China
| | - Wenhui Nie
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan650223, China
| | - Hu Zhou
- Department of Analytical Chemistry and Key Laboratory of Receptor Research of Chinese Academy of Sciences, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
| | - Jing Gao
- Department of Analytical Chemistry and Key Laboratory of Receptor Research of Chinese Academy of Sciences, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
| | - Ping Zheng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan650223, China
- Key Laboratory of Animal Models and Human Disease Mechanisms of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan650223, China
- The Chinese University of Hong Kong and Kunming Institute of Zoology Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan650223, China
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27
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Xu K, Du W, Zhuang X, Liang D, Mo Y, Wang J. Glycogen synthase kinase-3β mediates toll-like receptors 4/nuclear factor kappa-B-activated cerebral ischemia-reperfusion injury through regulation of fat mass and obesity-associated protein. Brain Circ 2023; 9:162-171. [PMID: 38020949 PMCID: PMC10679630 DOI: 10.4103/bc.bc_3_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 04/19/2023] [Accepted: 04/24/2023] [Indexed: 12/01/2023] Open
Abstract
BACKGROUND Glycogen synthase kinase-3β (GSK3β), fat mass and obesity-associated protein (FTO), and toll-like receptors 4 (TLR4) take on critical significance in different biological processes, whereas their interactions remain unclear. The objective was the investigation of the interaction effect in cerebral ischemia-reperfusion (I/R) injury. METHODS The function of the cerebral cortex in the mouse middle cerebral artery occlusion (MCAO) model (each group n = 6) and P12 cells oxygen-glucose deprivation/reoxygenation (OGD/R) model was analyzed using short hairpin GSK3β lentivirus and overexpression of FTO lentivirus (in vitro), TLR4 inhibitor (TAK242), and LiCl to regulate GSK3β, FTO, TLR4 expression, and GSK3β activity, respectively. RESULTS After GSK3β knockdown in the OGD/R model of PC12 cells, the levels of TLR4 and p-p65 were lower than in the control, and the level of FTO was higher than in the control. Knockdown GSK3β reversed the OGD/R-induced nuclear factor kappa-B transfer to the intranuclear nuclei. As indicated by the result, TLR4 expression was down-regulated by overexpressed FTO, and TLR4 expression was up-regulated notably after inhibition of FTO with the use of R-2HG. After the inhibition of the activity of GSK3β in vivo, the reduction of FTO in mice suffering from MCAO was reversed. CONCLUSIONS Our research shows that GSK3β/FTO/TLR4 pathway contributes to cerebral I/R injury.
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Affiliation(s)
- Kaiwei Xu
- Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Wenwen Du
- Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiuxiu Zhuang
- Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Dongdong Liang
- Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yunchang Mo
- Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Junlu Wang
- Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
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28
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Gu L, Hickey RJ, Malkas LH. Therapeutic Targeting of DNA Replication Stress in Cancer. Genes (Basel) 2023; 14:1346. [PMID: 37510250 PMCID: PMC10378776 DOI: 10.3390/genes14071346] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 07/30/2023] Open
Abstract
This article reviews the currently used therapeutic strategies to target DNA replication stress for cancer treatment in the clinic, highlighting their effectiveness and limitations due to toxicity and drug resistance. Cancer cells experience enhanced spontaneous DNA damage due to compromised DNA replication machinery, elevated levels of reactive oxygen species, loss of tumor suppressor genes, and/or constitutive activation of oncogenes. Consequently, these cells are addicted to DNA damage response signaling pathways and repair machinery to maintain genome stability and support survival and proliferation. Chemotherapeutic drugs exploit this genetic instability by inducing additional DNA damage to overwhelm the repair system in cancer cells. However, the clinical use of DNA-damaging agents is limited by their toxicity and drug resistance often arises. To address these issues, the article discusses a potential strategy to target the cancer-associated isoform of proliferating cell nuclear antigen (caPCNA), which plays a central role in the DNA replication and damage response network. Small molecule and peptide agents that specifically target caPCNA can selectively target cancer cells without significant toxicity to normal cells or experimental animals.
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Affiliation(s)
- Long Gu
- Department of Molecular Diagnostics & Experimental Therapeutics, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Robert J Hickey
- Department of Cancer Biology & Molecular Medicine, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Linda H Malkas
- Department of Molecular Diagnostics & Experimental Therapeutics, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
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29
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Oh JM, Kang Y, Park J, Sung Y, Kim D, Seo Y, Lee E, Ra J, Amarsanaa E, Park YU, Lee S, Hwang J, Kim H, Schärer O, Cho S, Lee C, Takata KI, Lee J, Myung K. MSH2-MSH3 promotes DNA end resection during homologous recombination and blocks polymerase theta-mediated end-joining through interaction with SMARCAD1 and EXO1. Nucleic Acids Res 2023; 51:5584-5602. [PMID: 37140056 PMCID: PMC10287916 DOI: 10.1093/nar/gkad308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 04/04/2023] [Accepted: 04/27/2023] [Indexed: 05/05/2023] Open
Abstract
DNA double-strand break (DSB) repair via homologous recombination is initiated by end resection. The extent of DNA end resection determines the choice of the DSB repair pathway. Nucleases for end resection have been extensively studied. However, it is still unclear how the potential DNA structures generated by the initial short resection by MRE11-RAD50-NBS1 are recognized and recruit proteins, such as EXO1, to DSB sites to facilitate long-range resection. We found that the MSH2-MSH3 mismatch repair complex is recruited to DSB sites through interaction with the chromatin remodeling protein SMARCAD1. MSH2-MSH3 facilitates the recruitment of EXO1 for long-range resection and enhances its enzymatic activity. MSH2-MSH3 also inhibits access of POLθ, which promotes polymerase theta-mediated end-joining (TMEJ). Collectively, we present a direct role of MSH2-MSH3 in the initial stages of DSB repair by promoting end resection and influencing the DSB repair pathway by favoring homologous recombination over TMEJ.
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Affiliation(s)
- Jung-Min Oh
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Oral Biochemistry, Dental and Life Science Institute, School of Dentistry, Pusan National University, Yangsan 50612, Republic of Korea
| | - Yujin Kang
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Jumi Park
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Yubin Sung
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Dayoung Kim
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Yuri Seo
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Eun A Lee
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Jae Sun Ra
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Enkhzul Amarsanaa
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Young-Un Park
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Seon Young Lee
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Jung Me Hwang
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Hongtae Kim
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Orlando Schärer
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Seung Woo Cho
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Changwook Lee
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Kei-ichi Takata
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Ja Yil Lee
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
| | - Kyungjae Myung
- Center for Genomic Integrity, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan44919, Republic of Korea
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30
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Chen H, Liu X, Li L, Tan Q, Li S, Li L, Li C, Fu J, Lu Y, Wang Y, Sun Y, Luo ZG, Lu Z, Sun Q, Liu Z. CATI: an efficient gene integration method for rodent and primate embryos by MMEJ suppression. Genome Biol 2023; 24:146. [PMID: 37353834 PMCID: PMC10288798 DOI: 10.1186/s13059-023-02987-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 06/13/2023] [Indexed: 06/25/2023] Open
Abstract
The efficiency of homology-directed repair (HDR) plays a crucial role in the development of animal models and gene therapy. We demonstrate that microhomology-mediated end-joining (MMEJ) constitutes a substantial proportion of DNA repair during CRISPR-mediated gene editing. Using CasRx to downregulate a key MMEJ factor, Polymerase Q (Polq), we improve the targeted integration efficiency of linearized DNA fragments and single-strand oligonucleotides (ssODN) in mouse embryos and offspring. CasRX-assisted targeted integration (CATI) also leads to substantial improvements in HDR efficiency during the CRISPR/Cas9 editing of monkey embryos. We present a promising tool for generating monkey models and developing gene therapies for clinical trials.
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Affiliation(s)
- Hongyu Chen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China
| | - Xingchen Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 19A Yu-Quan Road, Beijing, 100049, China
| | - Lanxin Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Qingtong Tan
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 19A Yu-Quan Road, Beijing, 100049, China
| | - Shiyan Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 19A Yu-Quan Road, Beijing, 100049, China
| | - Li Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China
| | - Chunyang Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China
| | - Jiqiang Fu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China
| | - Yong Lu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China
| | - Yan Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China
| | - Yidi Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, 201210, China
| | - Zhen-Ge Luo
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Zongyang Lu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China.
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, 201210, China.
| | - Qiang Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China.
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, 201210, China.
| | - Zhen Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science & Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, China.
- Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, 201210, China.
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31
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Smith CM, Gupta GP. Polymerase θ inhibition steps on the cGAS pedal. J Clin Invest 2023; 133:e170660. [PMID: 37259920 PMCID: PMC10231987 DOI: 10.1172/jci170660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023] Open
Abstract
Deficiencies in homologous recombination (HR) repair lead to an accumulation of DNA damage and can predispose individuals to cancer. Polymerase theta (Pol θ, encoded by POLQ) is overexpressed by HR-deficient cancers and promotes cancer cell survival by mediating error-prone double-stranded break (DSB) repair and facilitating resistance against poly-ADP ribose polymerase inhibitor treatment. In this issue of the JCI, Oh, Wang, et al. report on the impact of Pol θ inhibition on activation of antitumor immunity. The authors used pancreatic ductal adenocarcinoma (PDAC) cell and mouse models characterized by HR-associated gene alterations and POLQ overexpression. POLQ knockdown showed synthetic lethality in combination with gene mutations involving DNA repair, including BRCA1, BRCA2, and ATM. Notably, Pol θ deficiency or inhibition suppressed tumor growth, increased the accumulation of unrepaired DNA damage, and enhanced T cell infiltration via the cGAS/STING pathway. These findings suggest a broader scope for Pol θ inhibition in HR-deficient cancers.
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Affiliation(s)
- Chelsea M. Smith
- Lineberger Comprehensive Cancer Center
- Department of Pathology and Laboratory Medicine, and
| | - Gaorav P. Gupta
- Lineberger Comprehensive Cancer Center
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina, USA
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32
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Oh G, Wang A, Wang L, Li J, Werba G, Weissinger D, Zhao E, Dhara S, Hernandez RE, Ackermann A, Porcella S, Kalfakakou D, Dolgalev I, Kawaler E, Golan T, Welling TH, Sfeir A, Simeone DM. POLQ inhibition elicits an immune response in homologous recombination-deficient pancreatic adenocarcinoma via cGAS/STING signaling. J Clin Invest 2023; 133:e165934. [PMID: 36976649 PMCID: PMC10232002 DOI: 10.1172/jci165934] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 03/22/2023] [Indexed: 03/29/2023] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy that harbors mutations in homologous recombination-repair (HR-repair) proteins in 20%-25% of cases. Defects in HR impart a specific vulnerability to poly ADP ribose polymerase inhibitors and platinum-containing chemotherapy in tumor cells. However, not all patients who receive these therapies respond, and many who initially respond ultimately develop resistance. Inactivation of the HR pathway is associated with the overexpression of polymerase theta (Polθ, or POLQ). This key enzyme regulates the microhomology-mediated end-joining (MMEJ) pathway of double-strand break (DSB) repair. Using human and murine HR-deficient PDAC models, we found that POLQ knockdown is synthetically lethal in combination with mutations in HR genes such as BRCA1 and BRCA2 and the DNA damage repair gene ATM. Further, POLQ knockdown enhances cytosolic micronuclei formation and activates signaling of cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING), leading to enhanced infiltration of activated CD8+ T cells in BRCA2-deficient PDAC tumors in vivo. Overall, POLQ, a key mediator in the MMEJ pathway, is critical for DSB repair in BRCA2-deficient PDAC. Its inhibition represents a synthetic lethal approach to blocking tumor growth while concurrently activating the cGAS-STING signaling pathway to enhance tumor immune infiltration, highlighting what we believe to be a new role for POLQ in the tumor immune environment.
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Affiliation(s)
| | | | - Lidong Wang
- Perlmutter Cancer Center, NYU Langone Health, New York, New York, USA
| | - Jiufeng Li
- Perlmutter Cancer Center, NYU Langone Health, New York, New York, USA
| | - Gregor Werba
- Perlmutter Cancer Center, NYU Langone Health, New York, New York, USA
| | - Daniel Weissinger
- Perlmutter Cancer Center, NYU Langone Health, New York, New York, USA
| | - Ende Zhao
- Perlmutter Cancer Center, NYU Langone Health, New York, New York, USA
| | - Surajit Dhara
- Perlmutter Cancer Center, NYU Langone Health, New York, New York, USA
| | | | - Amanda Ackermann
- Perlmutter Cancer Center, NYU Langone Health, New York, New York, USA
| | - Sarina Porcella
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | | | - Igor Dolgalev
- Department of Pathology, NYU Langone Health, New York, New York, USA
| | - Emily Kawaler
- Perlmutter Cancer Center, NYU Langone Health, New York, New York, USA
| | | | | | - Agnel Sfeir
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Diane M. Simeone
- Department of Surgery and
- Perlmutter Cancer Center, NYU Langone Health, New York, New York, USA
- Department of Pathology, NYU Langone Health, New York, New York, USA
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33
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Rodriguez-Berriguete G, Ranzani M, Prevo R, Puliyadi R, Machado N, Bolland HR, Millar V, Ebner D, Boursier M, Cerutti A, Cicconi A, Galbiati A, Grande D, Grinkevich V, Majithiya JB, Piscitello D, Rajendra E, Stockley ML, Boulton SJ, Hammond EM, Heald RA, Smith GC, Robinson HM, Higgins GS. Small-Molecule Polθ Inhibitors Provide Safe and Effective Tumor Radiosensitization in Preclinical Models. Clin Cancer Res 2023; 29:1631-1642. [PMID: 36689546 PMCID: PMC10102842 DOI: 10.1158/1078-0432.ccr-22-2977] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/19/2022] [Accepted: 01/19/2023] [Indexed: 01/24/2023]
Abstract
PURPOSE DNA polymerase theta (Polθ, encoded by the POLQ gene) is a DNA repair enzyme critical for microhomology mediated end joining (MMEJ). Polθ has limited expression in normal tissues but is frequently overexpressed in cancer cells and, therefore, represents an ideal target for tumor-specific radiosensitization. In this study we evaluate whether targeting Polθ with novel small-molecule inhibitors is a feasible strategy to improve the efficacy of radiotherapy. EXPERIMENTAL DESIGN We characterized the response to Polθ inhibition in combination with ionizing radiation in different cancer cell models in vitro and in vivo. RESULTS Here, we show that ART558 and ART899, two novel and specific allosteric inhibitors of the Polθ DNA polymerase domain, potently radiosensitize tumor cells, particularly when combined with fractionated radiation. Importantly, noncancerous cells were not radiosensitized by Polθ inhibition. Mechanistically, we show that the radiosensitization caused by Polθ inhibition is most effective in replicating cells and is due to impaired DNA damage repair. We also show that radiosensitization is still effective under hypoxia, suggesting that these inhibitors may help overcome hypoxia-induced radioresistance. In addition, we describe for the first time ART899 and characterize it as a potent and specific Polθ inhibitor with improved metabolic stability. In vivo, the combination of Polθ inhibition using ART899 with fractionated radiation is well tolerated and results in a significant reduction in tumor growth compared with radiation alone. CONCLUSIONS These results pave the way for future clinical trials of Polθ inhibitors in combination with radiotherapy.
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Affiliation(s)
| | - Marco Ranzani
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | - Remko Prevo
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Rathi Puliyadi
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Nicole Machado
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Hannah R. Bolland
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Val Millar
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Daniel Ebner
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Marie Boursier
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | - Aurora Cerutti
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | | | | | - Diego Grande
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | - Vera Grinkevich
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | | | | | - Eeson Rajendra
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | | | - Simon J. Boulton
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
- The Francis Crick Institute, London, United Kingdom
| | - Ester M. Hammond
- Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Robert A. Heald
- Artios Pharma, Babraham Research Campus, Cambridge, United Kingdom
| | | | | | - Geoff S. Higgins
- Department of Oncology, University of Oxford, Oxford, United Kingdom
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Rai R, Biju K, Sun W, Sodeinde T, Al-Hiyasat A, Morgan J, Ye X, Li X, Chen Y, Chang S. Homology directed telomere clustering, ultrabright telomere formation and nuclear envelope rupture in cells lacking TRF2 B and RAP1. Nat Commun 2023; 14:2144. [PMID: 37059728 PMCID: PMC10104862 DOI: 10.1038/s41467-023-37761-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 03/30/2023] [Indexed: 04/16/2023] Open
Abstract
Double-strand breaks (DSBs) due to genotoxic stress represent potential threats to genome stability. Dysfunctional telomeres are recognized as DSBs and are repaired by distinct DNA repair mechanisms. RAP1 and TRF2 are telomere binding proteins essential to protect telomeres from engaging in homology directed repair (HDR), but how this occurs remains unclear. In this study, we examined how the basic domain of TRF2 (TRF2B) and RAP1 cooperate to repress HDR at telomeres. Telomeres lacking TRF2B and RAP1 cluster into structures termed ultrabright telomeres (UTs). HDR factors localize to UTs, and UT formation is abolished by RNaseH1, DDX21 and ADAR1p110, suggesting that they contain DNA-RNA hybrids. Interaction between the BRCT domain of RAP1 and KU70/KU80 is also required to repress UT formation. Expressing TRF2∆B in Rap1-/- cells resulted in aberrant lamin A localization in the nuclear envelope and dramatically increased UT formation. Expressing lamin A phosphomimetic mutants induced nuclear envelope rupturing and aberrant HDR-mediated UT formation. Our results highlight the importance of shelterin and proteins in the nuclear envelope in repressing aberrant telomere-telomere recombination to maintain telomere homeostasis.
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Affiliation(s)
- Rekha Rai
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA.
| | - Kevin Biju
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
- Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Wenqi Sun
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Tori Sodeinde
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
| | - Amer Al-Hiyasat
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
| | - Jaida Morgan
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
| | - Xianwen Ye
- University of Chinese Academy of Sciences, 100049, Beijing, China
- School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai, 201210, China
| | - Xueqing Li
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yong Chen
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
- School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai, 201210, China
| | - Sandy Chang
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA.
- Department of Pathology, Yale University School of Medicine, 330 Cedar Street, New Haven, CT, 06520, USA.
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, 330 Cedar Street, New Haven, CT, 06520, USA.
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35
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Yi G, Sung Y, Kim C, Ra JS, Hirakawa H, Kato T, Fujimori A, Kim H, Takata KI. DNA polymerase θ-mediated repair of high LET radiation-induced complex DNA double-strand breaks. Nucleic Acids Res 2023; 51:2257-2269. [PMID: 36805268 PMCID: PMC10018357 DOI: 10.1093/nar/gkad076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 01/21/2023] [Accepted: 01/25/2023] [Indexed: 02/22/2023] Open
Abstract
DNA polymerase θ (POLQ) is a unique DNA polymerase that is able to perform microhomology-mediated end-joining as well as translesion synthesis (TLS) across an abasic (AP) site and thymine glycol (Tg). However, the biological significance of the TLS activity is currently unknown. Herein we provide evidence that the TLS activity of POLQ plays a critical role in repairing complex DNA double-strand breaks (DSBs) induced by high linear energy transfer (LET) radiation. Radiotherapy with high LET radiation such as carbon ions leads to more deleterious biological effects than corresponding doses of low LET radiation such as X-rays. High LET-induced DSBs are considered to be complex, carrying additional DNA damage such as AP site and Tg in close proximity to the DSB sites. However, it is not clearly understood how complex DSBs are processed in mammalian cells. We demonstrated that genetic disruption of POLQ results in an increase of chromatid breaks and enhanced cellular sensitivity following treatment with high LET radiation. At the biochemical level, POLQ was able to bypass an AP site and Tg during end-joining and was able to anneal two single-stranded DNA tails when DNA lesions were located outside the microhomology. This study offers evidence that POLQ is directly involved in the repair of complex DSBs.
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Affiliation(s)
- Geunil Yi
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Republic of Korea
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Yubin Sung
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Republic of Korea
| | - Chanwoo Kim
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Jae Sun Ra
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Republic of Korea
| | - Hirokazu Hirakawa
- Department of Charged Particle Therapy Research, Institute for Quantum Medical Science, Chiba 263-8555, Japan
| | - Takamitsu A Kato
- Department of Environmental & Radiological Health Sciences, Colorado State University, Colorado 80523, USA
| | - Akira Fujimori
- Department of Charged Particle Therapy Research, Institute for Quantum Medical Science, Chiba 263-8555, Japan
| | - Hajin Kim
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Republic of Korea
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Kei-ichi Takata
- Center for Genomic Integrity, Institute for Basic Science, Ulsan 44919, Republic of Korea
- Department of Biological Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
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36
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van de Kooij B, Schreuder A, Pavani RS, Garzero V, Van Hoeck A, San Martin Alonso M, Koerse D, Wendel TJ, Callen E, Boom J, Mei H, Cuppen E, Nussenzweig A, van Attikum H, Noordermeer SM. EXO1-mediated DNA repair by single-strand annealing is essential for BRCA1-deficient cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.24.529205. [PMID: 37720033 PMCID: PMC10503826 DOI: 10.1101/2023.02.24.529205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Deficiency for the repair of DNA double-strand breaks (DSBs) via homologous recombination (HR) leads to chromosomal instability and diseases such as cancer. Yet, defective HR also results in vulnerabilities that can be exploited for targeted therapy. Here, we identify such a vulnerability and show that BRCA1-deficient cells are dependent on the long-range end-resection factor EXO1 for survival. EXO1 loss results in DNA replication-induced lesions decorated by poly(ADP-ribose)-chains. In cells that lack both BRCA1 and EXO1, this is accompanied by unresolved DSBs due to impaired single-strand annealing (SSA), a DSB repair process that requires the activity of both proteins. In contrast, BRCA2-deficient cells have increased SSA, also in the absence of EXO1, and hence are not dependent on EXO1 for survival. In agreement with our mechanistic data, BRCA1-mutated tumours have elevated EXO1 expression and contain more genomic signatures of SSA compared to BRCA1-proficient tumours. Collectively, our data indicate that EXO1 is a promising novel target for treatment of BRCA1-deficient tumours.
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37
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Groelly FJ, Fawkes M, Dagg RA, Blackford AN, Tarsounas M. Targeting DNA damage response pathways in cancer. Nat Rev Cancer 2023; 23:78-94. [PMID: 36471053 DOI: 10.1038/s41568-022-00535-5] [Citation(s) in RCA: 200] [Impact Index Per Article: 200.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/01/2022] [Indexed: 12/12/2022]
Abstract
Cells have evolved a complex network of biochemical pathways, collectively known as the DNA damage response (DDR), to prevent detrimental mutations from being passed on to their progeny. The DDR coordinates DNA repair with cell-cycle checkpoint activation and other global cellular responses. Genes encoding DDR factors are frequently mutated in cancer, causing genomic instability, an intrinsic feature of many tumours that underlies their ability to grow, metastasize and respond to treatments that inflict DNA damage (such as radiotherapy). One instance where we have greater insight into how genetic DDR abrogation impacts on therapy responses is in tumours with mutated BRCA1 or BRCA2. Due to compromised homologous recombination DNA repair, these tumours rely on alternative repair mechanisms and are susceptible to chemical inhibitors of poly(ADP-ribose) polymerase (PARP), which specifically kill homologous recombination-deficient cancer cells, and have become a paradigm for targeted cancer therapy. It is now clear that many other synthetic-lethal relationships exist between DDR genes. Crucially, some of these interactions could be exploited in the clinic to target tumours that become resistant to PARP inhibition. In this Review, we discuss state-of-the-art strategies for DDR inactivation using small-molecule inhibitors and highlight those compounds currently being evaluated in the clinic.
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Affiliation(s)
- Florian J Groelly
- Genome Stability and Tumourigenesis Group, Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
| | - Matthew Fawkes
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Rebecca A Dagg
- Genome Stability and Tumourigenesis Group, Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
| | - Andrew N Blackford
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK.
| | - Madalena Tarsounas
- Genome Stability and Tumourigenesis Group, Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
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38
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Li C, Zhu H, Jin S, Maksoud LM, Jain N, Sun J, Gao Y. Structural basis of DNA polymerase θ mediated DNA end joining. Nucleic Acids Res 2023; 51:463-474. [PMID: 36583344 PMCID: PMC9841435 DOI: 10.1093/nar/gkac1201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/30/2022] [Accepted: 12/05/2022] [Indexed: 12/31/2022] Open
Abstract
DNA polymerase θ (Pol θ) plays an essential role in the microhomology-mediated end joining (MMEJ) pathway for repairing DNA double-strand breaks. However, the mechanisms by which Pol θ recognizes microhomologous DNA ends and performs low-fidelity DNA synthesis remain unclear. Here, we present cryo-electron microscope structures of the polymerase domain of Lates calcarifer Pol θ with long and short duplex DNA at up to 2.4 Å resolution. Interestingly, Pol θ binds to long and short DNA substrates similarly, with extensive interactions around the active site. Moreover, Pol θ shares a similar active site as high-fidelity A-family polymerases with its finger domain well-closed but differs in having hydrophilic residues surrounding the nascent base pair. Computational simulations and mutagenesis studies suggest that the unique insertion loops of Pol θ help to stabilize short DNA binding and assemble the active site for MMEJ repair. Taken together, our results illustrate the structural basis of Pol θ-mediated MMEJ.
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Affiliation(s)
- Chuxuan Li
- Department of Biosciences, Rice University, Houston, TX 77005, USA
| | - Hanwen Zhu
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Shikai Jin
- Department of Biosciences, Rice University, Houston, TX 77005, USA
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
| | - Leora M Maksoud
- Department of Biosciences, Rice University, Houston, TX 77005, USA
| | - Nikhil Jain
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Ji Sun
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Yang Gao
- Department of Biosciences, Rice University, Houston, TX 77005, USA
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39
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Polλ promotes microhomology-mediated end-joining. Nat Struct Mol Biol 2023; 30:107-114. [PMID: 36536104 DOI: 10.1038/s41594-022-00895-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 11/04/2022] [Indexed: 12/24/2022]
Abstract
The double-strand break (DSB) repair pathway called microhomology-mediated end-joining (MMEJ) is thought to be dependent on DNA polymerase theta (Polθ) and occur independently of nonhomologous end-joining (NHEJ) factors. An unresolved question is whether MMEJ is facilitated by a single Polθ-mediated end-joining pathway or consists of additional undiscovered pathways. We find that human X-family Polλ, which functions in NHEJ, additionally exhibits robust MMEJ activity like Polθ. Polλ promotes MMEJ in mammalian cells independently of essential NHEJ factors LIG4/XRCC4 and Polθ, which reveals a distinct Polλ-dependent MMEJ mechanism. X-ray crystallography employing in situ photo-induced DSB formation captured Polλ in the act of stabilizing a microhomology-mediated DNA synapse with incoming nucleotide at 2.0 Å resolution and reveals how Polλ performs replication across a DNA synapse joined by minimal base-pairing. Last, we find that Polλ is semisynthetic lethal with BRCA1 and BRCA2. Together, these studies indicate Polλ MMEJ as a distinct DSB repair mechanism.
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40
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Patterson-Fortin J, D'Andrea AD. Targeting Polymerase Theta (POLθ) for Cancer Therapy. Cancer Treat Res 2023; 186:285-298. [PMID: 37978141 DOI: 10.1007/978-3-031-30065-3_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
Polymerase theta (POLθ) is the critical multi-domain enzyme in microhomology-mediated end-joining DNA double-stranded break repair. POLθ is expressed at low levels in normal tissue but is often overexpressed in cancers, especially in DNA repair deficient cancers, such as homologous-recombination cancers, rendering them exquisitely sensitive to POLθ inhibition secondary to synthetic lethality. Development of POLθ inhibitors is an active area of investigation with inhibitors of the N-terminal helicase domain or the C-terminal polymerase domain currently in clinical trial. Here, we review POLθ-mediated microhomology-mediated end-joining, the development of POLθ inhibitors, and the potential clinical uses of POLθ inhibitors.
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Affiliation(s)
- Jeffrey Patterson-Fortin
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA
| | - Alan D D'Andrea
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, 02215, USA.
- Harvard Medical School, Center for DNA Damage and Repair, Susan F. Smith Center for Women's Cancers (SFSCWC), The Fuller-American Cancer Society, Dana-Farber Cancer Institute, HIM 243, 450 Brookline Ave., Boston, MA, 02215, USA.
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41
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Abstract
DNA polymerase θ (Pol θ) is a DNA repair enzyme widely conserved in animals and plants. Pol θ uses short DNA sequence homologies to initiate repair of double-strand breaks by theta-mediated end joining. The DNA polymerase domain of Pol θ is at the C terminus and is connected to an N-terminal DNA helicase-like domain by a central linker. Pol θ is crucial for maintenance of damaged genomes during development, protects DNA against extensive deletions, and limits loss of heterozygosity. The cost of using Pol θ for genome protection is that a few nucleotides are usually deleted or added at the repair site. Inactivation of Pol θ often enhances the sensitivity of cells to DNA strand-breaking chemicals and radiation. Since some homologous recombination-defective cancers depend on Pol θ for growth, inhibitors of Pol θ may be useful in treating such tumors.
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Affiliation(s)
- Richard D Wood
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Center, Houston, Texas, USA;
| | - Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, USA;
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42
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Pre-Existing and Acquired Resistance to PARP Inhibitor-Induced Synthetic Lethality. Cancers (Basel) 2022; 14:cancers14235795. [PMID: 36497275 PMCID: PMC9741207 DOI: 10.3390/cancers14235795] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/17/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022] Open
Abstract
The advanced development of synthetic lethality has opened the doors for specific anti-cancer medications of personalized medicine and efficient therapies against cancers. One of the most popular approaches being investigated is targeting DNA repair pathways as the implementation of the PARP inhibitor (PARPi) into individual or combinational therapeutic schemes. Such treatment has been effectively employed against homologous recombination-defective solid tumors as well as hematopoietic malignancies. However, the resistance to PARPi has been observed in both preclinical research and clinical treatment. Therefore, elucidating the mechanisms responsible for the resistance to PARPi is pivotal for the further success of this intervention. Apart from mechanisms of acquired resistance, the bone marrow microenvironment provides a pre-existing mechanism to induce the inefficiency of PARPi in leukemic cells. Here, we describe the pre-existing and acquired mechanisms of the resistance to PARPi-induced synthetic lethality. We also discuss the potential rationales for developing effective therapies to prevent/repress the PARPi resistance in cancer cells.
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43
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Baxter JS, Zatreanu D, Pettitt SJ, Lord CJ. Resistance to DNA repair inhibitors in cancer. Mol Oncol 2022; 16:3811-3827. [PMID: 35567571 PMCID: PMC9627783 DOI: 10.1002/1878-0261.13224] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/25/2022] [Accepted: 05/12/2022] [Indexed: 12/24/2022] Open
Abstract
The DNA damage response (DDR) represents a complex network of proteins which detect and repair DNA damage, thereby maintaining the integrity of the genome and preventing the transmission of mutations and rearranged chromosomes to daughter cells. Faults in the DDR are a known driver and hallmark of cancer. Furthermore, inhibition of DDR enzymes can be used to treat the disease. This is exemplified by PARP inhibitors (PARPi) used to treat cancers with defects in the homologous recombination DDR pathway. A series of novel DDR targets are now also under pre-clinical or clinical investigation, including inhibitors of ATR kinase, WRN helicase or the DNA polymerase/helicase Polθ (Pol-Theta). Drug resistance is a common phenomenon that impairs the overall effectiveness of cancer treatments and there is already some understanding of how resistance to PARPi occurs. Here, we discuss how an understanding of PARPi resistance could inform how resistance to new drugs targeting the DDR emerges. We also discuss potential strategies that could limit the impact of these therapy resistance mechanisms in cancer.
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Affiliation(s)
- Joseph S. Baxter
- The CRUK Gene Function Laboratory and Breast Cancer Now Toby Robins Research CentreThe Institute of Cancer ResearchLondonUK
| | - Diana Zatreanu
- The CRUK Gene Function Laboratory and Breast Cancer Now Toby Robins Research CentreThe Institute of Cancer ResearchLondonUK
| | - Stephen J. Pettitt
- The CRUK Gene Function Laboratory and Breast Cancer Now Toby Robins Research CentreThe Institute of Cancer ResearchLondonUK
| | - Christopher J. Lord
- The CRUK Gene Function Laboratory and Breast Cancer Now Toby Robins Research CentreThe Institute of Cancer ResearchLondonUK
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44
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Stockley ML, Ferdinand A, Benedetti G, Blencowe P, Boyd SM, Calder M, Charles MD, Edwardes LV, Ekwuru T, Finch H, Galbiati A, Geo L, Grande D, Grinkevich V, Holliday ND, Krajewski WW, MacDonald E, Majithiya JB, McCarron H, McWhirter CL, Patel V, Pedder C, Rajendra E, Ranzani M, Rigoreau LJM, Robinson HMR, Schaedler T, Sirina J, Smith GCM, Swarbrick ME, Turnbull AP, Willis S, Heald RA. Discovery, Characterization, and Structure-Based Optimization of Small-Molecule In Vitro and In Vivo Probes for Human DNA Polymerase Theta. J Med Chem 2022; 65:13879-13891. [PMID: 36200480 DOI: 10.1021/acs.jmedchem.2c01142] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human DNA polymerase theta (Polθ), which is essential for microhomology-mediated DNA double strand break repair, has been proposed as an attractive target for the treatment of BRCA deficient and other DNA repair pathway defective cancers. As previously reported, we recently identified the first selective small molecule Polθ in vitro probe, 22 (ART558), which recapitulates the phenotype of Polθ loss, and in vivo probe, 43 (ART812), which is efficacious in a model of PARP inhibitor resistant TNBC in vivo. Here we describe the discovery, biochemical and biophysical characterization of these probes including small molecule ligand co-crystal structures with Polθ. The crystallographic data provides a basis for understanding the unique mechanism of inhibition of these compounds which is dependent on stabilization of a "closed" enzyme conformation. Additionally, the structural biology platform provided a basis for rational optimization based primarily on reduced ligand conformational flexibility.
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Affiliation(s)
- Martin L Stockley
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Amanda Ferdinand
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Giovanni Benedetti
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Peter Blencowe
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Susan M Boyd
- CompChem Solutions Ltd, St John's Innovation Centre, Cowley Rd, CambridgeCB4 0WS, U. K
| | - Mat Calder
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Mark D Charles
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Lucy V Edwardes
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Tennyson Ekwuru
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Harry Finch
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | | | - Lerin Geo
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Diego Grande
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Vera Grinkevich
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Nicholas D Holliday
- Excellerate Bioscience Ltd., BioCity, Pennyfoot Street, NottinghamNG1 1GF, U. K
| | - Wojciech W Krajewski
- Cancer Research Horizons Therapeutic Innovation, The Francis Crick Institute, 1 Midland Road, LondonNW1 1AT, U. K
| | - Ellen MacDonald
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Jayesh B Majithiya
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Hollie McCarron
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Claire L McWhirter
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Viral Patel
- Excellerate Bioscience Ltd., BioCity, Pennyfoot Street, NottinghamNG1 1GF, U. K
| | - Chris Pedder
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Eeson Rajendra
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Marco Ranzani
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Laurent J M Rigoreau
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Helen M R Robinson
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Theresia Schaedler
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Julija Sirina
- Excellerate Bioscience Ltd., BioCity, Pennyfoot Street, NottinghamNG1 1GF, U. K
| | - Graeme C M Smith
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
| | - Martin E Swarbrick
- Cancer Research Horizons Therapeutic Innovation, Jonas Webb Building, Babraham Research Campus, CambridgeCB22 3AT, U. K
| | - Andrew P Turnbull
- Cancer Research Horizons Therapeutic Innovation, The Francis Crick Institute, 1 Midland Road, LondonNW1 1AT, U. K
| | - Simon Willis
- Cancer Research Horizons Therapeutic Innovation, The Francis Crick Institute, 1 Midland Road, LondonNW1 1AT, U. K
| | - Robert A Heald
- Artios Pharma Ltd., B940, Babraham Research Campus, CambridgeCB22 3FH, U. K
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45
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Jiang Y. Contribution of Microhomology to Genome Instability: Connection between DNA Repair and Replication Stress. Int J Mol Sci 2022; 23:12937. [PMID: 36361724 PMCID: PMC9657218 DOI: 10.3390/ijms232112937] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/23/2022] [Accepted: 10/23/2022] [Indexed: 11/23/2023] Open
Abstract
Microhomology-mediated end joining (MMEJ) is a highly mutagenic pathway to repair double-strand breaks (DSBs). MMEJ was thought to be a backup pathway of homologous recombination (HR) and canonical nonhomologous end joining (C-NHEJ). However, it attracts more attention in cancer research due to its special function of microhomology in many different aspects of cancer. In particular, it is initiated with DNA end resection and upregulated in homologous recombination-deficient cancers. In this review, I summarize the following: (1) the recent findings and contributions of MMEJ to genome instability, including phenotypes relevant to MMEJ; (2) the interaction between MMEJ and other DNA repair pathways; (3) the proposed mechanistic model of MMEJ in DNA DSB repair and a new connection with microhomology-mediated break-induced replication (MMBIR); and (4) the potential clinical application by targeting MMEJ based on synthetic lethality for cancer therapy.
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Affiliation(s)
- Yuning Jiang
- Department of Radiation Oncology, University of Virginia, Charlottesville, VA 22903, USA
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46
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Bubenik M, Mader P, Mochirian P, Vallée F, Clark J, Truchon JF, Perryman AL, Pau V, Kurinov I, Zahn KE, Leclaire ME, Papp R, Mathieu MC, Hamel M, Duffy NM, Godbout C, Casas-Selves M, Falgueyret JP, Baruah PS, Nicolas O, Stocco R, Poirier H, Martino G, Fortin AB, Roulston A, Chefson A, Dorich S, St-Onge M, Patel P, Pellerin C, Ciblat S, Pinter T, Barabé F, Bakkouri ME, Parikh P, Gervais C, Sfeir A, Mamane Y, Morris SJ, Black WC, Sicheri F, Gallant M. Identification of RP-6685, an Orally Bioavailable Compound that Inhibits the DNA Polymerase Activity of Polθ. J Med Chem 2022; 65:13198-13215. [PMID: 36126059 PMCID: PMC9942948 DOI: 10.1021/acs.jmedchem.2c00998] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DNA polymerase theta (Polθ) is an attractive synthetic lethal target for drug discovery, predicted to be efficacious against breast and ovarian cancers harboring BRCA-mutant alleles. Here, we describe our hit-to-lead efforts in search of a selective inhibitor of human Polθ (encoded by POLQ). A high-throughput screening campaign of 350,000 compounds identified an 11 micromolar hit, giving rise to the N2-substituted fused pyrazolo series, which was validated by biophysical methods. Structure-based drug design efforts along with optimization of cellular potency and ADME ultimately led to the identification of RP-6685: a potent, selective, and orally bioavailable Polθ inhibitor that showed in vivo efficacy in an HCT116 BRCA2-/- mouse tumor xenograft model.
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Affiliation(s)
- Monica Bubenik
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Pavel Mader
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5G 1X5, Canada
| | - Philippe Mochirian
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Fréderic Vallée
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Jillian Clark
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Jean-François Truchon
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Alexander L. Perryman
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Victor Pau
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5G 1X5, Canada
| | - Igor Kurinov
- Department of Chemistry and Chemical Biology, Cornell University, NE-CAT, Argonne, Illinois 60439, USA
| | - Karl E. Zahn
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Marie-Eve Leclaire
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Robert Papp
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Marie-Claude Mathieu
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Martine Hamel
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Nicole M. Duffy
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Claude Godbout
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Matias Casas-Selves
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Jean-Pierre Falgueyret
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Prasamit S. Baruah
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Olivier Nicolas
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Rino Stocco
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Hugo Poirier
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Giovanni Martino
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | | | - Anne Roulston
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Amandine Chefson
- Ventus Therapeutics 7150 Frederick-Banting suite 200, Montréal, Québec, H4S 2A1, Canada
| | - Stéphane Dorich
- Ventus Therapeutics 7150 Frederick-Banting suite 200, Montréal, Québec, H4S 2A1, Canada
| | - Miguel St-Onge
- Ventus Therapeutics 7150 Frederick-Banting suite 200, Montréal, Québec, H4S 2A1, Canada
| | - Purvish Patel
- Ventus Therapeutics 7150 Frederick-Banting suite 200, Montréal, Québec, H4S 2A1, Canada
| | - Charles Pellerin
- Ventus Therapeutics 7150 Frederick-Banting suite 200, Montréal, Québec, H4S 2A1, Canada
| | - Stéphane Ciblat
- Ventus Therapeutics 7150 Frederick-Banting suite 200, Montréal, Québec, H4S 2A1, Canada
- Paraza Pharma Inc., 2525 Ave. Marie Curie, Montréal, Québec, H4S 1Z9, Canada
| | - Thomas Pinter
- Paraza Pharma Inc., 2525 Ave. Marie Curie, Montréal, Québec, H4S 1Z9, Canada
| | - Francis Barabé
- Paraza Pharma Inc., 2525 Ave. Marie Curie, Montréal, Québec, H4S 1Z9, Canada
| | - Majida El Bakkouri
- Paraza Pharma Inc., 2525 Ave. Marie Curie, Montréal, Québec, H4S 1Z9, Canada
- National Research Council of Canada, 6100 Royalmount Ave, Montréal, Québec, H4P 2R2, Canada
| | - Paranjay Parikh
- Piramal Pharma Ltd., Plot No. 18, Village Matoda, Taluka: Sanand, Ahmedabad-382213, Gujarat, India
| | - Christian Gervais
- National Research Council of Canada, 6100 Royalmount Ave, Montréal, Québec, H4P 2R2, Canada
| | - Agnel Sfeir
- Molecular Biology Program, Sloan Kettering Institute, MSKCC, 430 E 67th Street, New York, NY 10065, USA
| | - Yael Mamane
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Stephen J. Morris
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - W. Cameron Black
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
| | - Frank Sicheri
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario, M5G 1X5, Canada
| | - Michel Gallant
- Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9, Montréal, Québec, Canada
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47
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Wilson C, Murnane JP. High-throughput screen to identify compounds that prevent or target telomere loss in human cancer cells. NAR Cancer 2022; 4:zcac029. [PMID: 36196242 PMCID: PMC9527662 DOI: 10.1093/narcan/zcac029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/09/2022] [Accepted: 09/29/2022] [Indexed: 11/14/2022] Open
Abstract
Chromosome instability (CIN) is an early step in carcinogenesis that promotes tumor cell progression and resistance to therapy. Using plasmids integrated adjacent to telomeres, we have previously demonstrated that the sensitivity of subtelomeric regions to DNA double-strand breaks (DSBs) contributes to telomere loss and CIN in cancer. A high-throughput screen was created to identify compounds that affect telomere loss due to subtelomeric DSBs introduced by I-SceI endonuclease, as detected by cells expressing green fluorescent protein (GFP). A screen of a library of 1832 biologically-active compounds identified a variety of compounds that increase or decrease the number of GFP-positive cells following activation of I-SceI. A curated screen done in triplicate at various concentrations found that inhibition of classical nonhomologous end joining (C-NHEJ) increased DSB-induced telomere loss, demonstrating that C-NHEJ is functional in subtelomeric regions. Compounds that decreased DSB-induced telomere loss included inhibitors of mTOR, p38 and tankyrase, consistent with our earlier hypothesis that the sensitivity of subtelomeric regions to DSBs is a result of inappropriate resection during repair. Although this assay was also designed to identify compounds that selectively target cells experiencing telomere loss and/or chromosome instability, no compounds of this type were identified in the current screen.
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Affiliation(s)
- Chris Wilson
- Department of Pharmaceutical Chemistry, Small Molecule Discovery Center, University of California, San Francisco, CA 94143, USA
| | - John P Murnane
- To whom correspondence should be addressed. Tel: +1 415 680 4434;
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48
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Liddiard K, Aston-Evans AN, Cleal K, Hendrickson E, Baird D. POLQ suppresses genome instability and alterations in DNA repeat tract lengths. NAR Cancer 2022; 4:zcac020. [PMID: 35774233 PMCID: PMC9241439 DOI: 10.1093/narcan/zcac020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/19/2022] [Accepted: 06/10/2022] [Indexed: 11/26/2022] Open
Abstract
DNA polymerase theta (POLQ) is a principal component of the alternative non-homologous end-joining (ANHEJ) DNA repair pathway that ligates DNA double-strand breaks. Utilizing independent models of POLQ insufficiency during telomere-driven crisis, we found that POLQ - /- cells are resistant to crisis-induced growth deceleration despite sustaining inter-chromosomal telomere fusion frequencies equivalent to wild-type (WT) cells. We recorded longer telomeres in POLQ - / - than WT cells pre- and post-crisis, notwithstanding elevated total telomere erosion and fusion rates. POLQ - /- cells emerging from crisis exhibited reduced incidence of clonal gross chromosomal abnormalities in accordance with increased genetic heterogeneity. High-throughput sequencing of telomere fusion amplicons from POLQ-deficient cells revealed significantly raised frequencies of inter-chromosomal fusions with correspondingly depreciated intra-chromosomal recombinations. Long-range interactions culminating in telomere fusions with centromere alpha-satellite repeats, as well as expansions in HSAT2 and HSAT3 satellite and contractions in ribosomal DNA repeats, were detected in POLQ - / - cells. In conjunction with the expanded telomere lengths of POLQ - /- cells, these results indicate a hitherto unrealized capacity of POLQ for regulation of repeat arrays within the genome. Our findings uncover novel considerations for the efficacy of POLQ inhibitors in clinical cancer interventions, where potential genome destabilizing consequences could drive clonal evolution and resistant disease.
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Affiliation(s)
- Kate Liddiard
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Alys N Aston-Evans
- Dementia Research Institute, School of Medicine, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff CF24 4HQ, UK
| | - Kez Cleal
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Eric A Hendrickson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Duncan M Baird
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
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Reshetnikov VV, Chirinskaite AV, Sopova JV, Ivanov RA, Leonova EI. Translational potential of base-editing tools for gene therapy of monogenic diseases. Front Bioeng Biotechnol 2022; 10:942440. [PMID: 36032737 PMCID: PMC9399415 DOI: 10.3389/fbioe.2022.942440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/14/2022] [Indexed: 12/26/2022] Open
Abstract
Millions of people worldwide have rare genetic diseases that are caused by various mutations in DNA sequence. Classic treatments of rare genetic diseases are often ineffective, and therefore great hopes are placed on gene-editing methods. A DNA base–editing system based on nCas9 (Cas9 with a nickase activity) or dCas9 (a catalytically inactive DNA-targeting Cas9 enzyme) enables editing without double-strand breaks. These tools are constantly being improved, which increases their potential usefulness for therapies. In this review, we describe the main types of base-editing systems and their application to the treatment of monogenic diseases in experiments in vitro and in vivo. Additionally, to understand the therapeutic potential of these systems, the advantages and disadvantages of base-editing systems are examined.
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Affiliation(s)
- Vasiliy V. Reshetnikov
- Department of Biotechnology, Sirius University of Science and Technology, Sochi, Russia
- Department of Molecular Genetics, Institute of Cytology and Genetics, Novosibirsk, Russia
| | - Angelina V. Chirinskaite
- Сenter of Transgenesis and Genome Editing, St. Petersburg State University, St. Petersburg, Russia
| | - Julia V. Sopova
- Сenter of Transgenesis and Genome Editing, St. Petersburg State University, St. Petersburg, Russia
- Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg, Russia
| | - Roman A. Ivanov
- Department of Biotechnology, Sirius University of Science and Technology, Sochi, Russia
| | - Elena I. Leonova
- Сenter of Transgenesis and Genome Editing, St. Petersburg State University, St. Petersburg, Russia
- Scientific Center for Genetics and Life Sciences, Sirius University of Science and Technology, Sochi, Russia
- *Correspondence: Elena I. Leonova,
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Poly(ADP) ribose polymerase promotes DNA polymerase theta-mediated end joining by activation of end resection. Nat Commun 2022; 13:4547. [PMID: 35927262 PMCID: PMC9352658 DOI: 10.1038/s41467-022-32166-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 07/18/2022] [Indexed: 11/29/2022] Open
Abstract
The DNA polymerase theta (Polθ)-mediated end joining (TMEJ) pathway for repair of chromosomal double strand breaks (DSBs) is essential in cells deficient in other DSB repair pathways, including hereditary breast cancers defective in homologous recombination. Strand-break activated poly(ADP) ribose polymerase 1 (PARP1) has been implicated in TMEJ, but the modest specificity of existing TMEJ assays means the extent of effect and the mechanism behind it remain unclear. We describe here a series of TMEJ assays with improved specificity and show ablation of PARP activity reduces TMEJ activity 2-4-fold. The reduction in TMEJ is attributable to a reduction in the 5’ to 3’ resection of DSB ends that is essential for engagement of this pathway and is compensated by increased repair by the nonhomologous-end joining pathway. This limited role for PARP activity in TMEJ helps better rationalize the combined employment of inhibitors of PARP and Polθ in cancer therapy. Poly(ADP) ribose polymerase (PARP) activity promotes, but is not required for, chromosome break repair by polymerase theta-mediated end joining (TMEJ). PARP activity promotes TMEJ by stimulating resection, a process that controls pathway choice.
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