1
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Gilioli G, Lankester A, de Kivit S, Staal FJT, Ott de Bruin LM. Gene Therapy Strategies for RAG1 Deficiency: Challenges and Breakthroughs. Immunol Lett 2024:106931. [PMID: 39303994 DOI: 10.1016/j.imlet.2024.106931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2024] [Revised: 09/14/2024] [Accepted: 09/17/2024] [Indexed: 09/22/2024]
Abstract
Mutations in the recombination activating genes (RAG) cause various forms of immune deficiency. Hematopoietic stem cell transplant (HSCT) is the only cure for patients with severe manifestations of RAG deficiency; however, outcomes are suboptimal with mismatched donors. Gene therapy aims to correct autologous hematopoietic stem and progenitor cells (HSPC) and is emerging as an alternative to allogeneic HSCT. Gene therapy based on viral gene addition exploits viral vectors to add a correct copy of a mutated gene into the genome of HSPCs. Only recently, after a prolonged phase of development, viral gene addition has been approved for clinical testing in RAG1-SCID patients. In the meantime, a new technology, CRISPR/Cas9, has made its debut to compete with viral gene addition. Gene editing based on CRISPR/Cas9 allows to perform targeted genomic integrations of a correct copy of a mutated gene, circumventing the risk of virus-mediated insertional mutagenesis. In this review, we present the biology of the RAG genes, the challenges faced during the development of viral gene addition for RAG1-SCID, and the current status of gene therapy for RAG1 deficiency. In particular, we highlight the latest advances and challenges in CRISPR/Cas9 gene editing and their potential for the future of gene therapy.
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Affiliation(s)
- Giorgio Gilioli
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Arjan Lankester
- Willem-Alexander Children's Hospital, Department of Pediatrics, Pediatric Stem Cell Transplantation Program and Laboratory for Pediatric Immunology.
| | - Sander de Kivit
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Frank J T Staal
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Lisa M Ott de Bruin
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands; Willem-Alexander Children's Hospital, Department of Pediatrics, Pediatric Stem Cell Transplantation Program and Laboratory for Pediatric Immunology.
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2
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Nusawardhana A, Pale LM, Nicolae CM, Moldovan GL. USP1-dependent nucleolytic expansion of PRIMPOL-generated nascent DNA strand discontinuities during replication stress. Nucleic Acids Res 2024; 52:2340-2354. [PMID: 38180818 PMCID: PMC10954467 DOI: 10.1093/nar/gkad1237] [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: 08/24/2023] [Revised: 12/11/2023] [Accepted: 12/15/2023] [Indexed: 01/07/2024] Open
Abstract
DNA replication stress-induced fork arrest represents a significant threat to genomic integrity. One major mechanism of replication restart involves repriming downstream of the arrested fork by PRIMPOL, leaving behind a single-stranded DNA (ssDNA) gap. Accumulation of nascent strand ssDNA gaps has emerged as a possible determinant of the cellular hypersensitivity to genotoxic agents in certain genetic backgrounds such as BRCA deficiency, but how gaps are converted into cytotoxic structures is still unclear. Here, we investigate the processing of PRIMPOL-dependent ssDNA gaps upon replication stress induced by hydroxyurea and cisplatin. We show that gaps generated in PRIMPOL-overexpressing cells are expanded in the 3'-5' direction by the MRE11 exonuclease, and in the 5'-3' direction by the EXO1 exonuclease. This bidirectional exonucleolytic gap expansion ultimately promotes their conversion into DSBs. We moreover identify the de-ubiquitinating enzyme USP1 as a critical regulator of PRIMPOL-generated ssDNA gaps. USP1 promotes gap accumulation during S-phase, and their expansion by the MRE11 and EXO1 nucleases. This activity of USP1 is linked to its role in de-ubiquitinating PCNA, suggesting that PCNA ubiquitination prevents gap accumulation during replication. Finally, we show that USP1 depletion suppresses DSB formation in PRIMPOL-overexpressing cells, highlighting an unexpected role for USP1 in promoting genomic instability under these conditions.
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Affiliation(s)
- Alexandra Nusawardhana
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Lindsey M Pale
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Claudia M Nicolae
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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3
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Rajendra E, Grande D, Mason B, Di Marcantonio D, Armstrong L, Hewitt G, Elinati E, Galbiati A, Boulton SJ, Heald RA, Smith GCM, Robinson HMR. Quantitative, titratable and high-throughput reporter assays to measure DNA double strand break repair activity in cells. Nucleic Acids Res 2024; 52:1736-1752. [PMID: 38109306 PMCID: PMC10899754 DOI: 10.1093/nar/gkad1196] [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: 05/25/2023] [Revised: 11/27/2023] [Accepted: 12/06/2023] [Indexed: 12/20/2023] Open
Abstract
Repair of DNA damage is essential for the maintenance of genome stability and cell viability. DNA double strand breaks (DSBs) constitute a toxic class of DNA lesion and multiple cellular pathways exist to mediate their repair. Robust and titratable assays of cellular DSB repair (DSBR) are important to functionally interrogate the integrity and efficiency of these mechanisms in disease models as well as in response to genetic or pharmacological perturbations. Several variants of DSBR reporters are available, however these are often limited by throughput or restricted to specific cellular models. Here, we describe the generation and validation of a suite of extrachromosomal reporter assays that can efficiently measure the major DSBR pathways of homologous recombination (HR), classical nonhomologous end joining (cNHEJ), microhomology-mediated end joining (MMEJ) and single strand annealing (SSA). We demonstrate that these assays can be adapted to a high-throughput screening format and that they are sensitive to pharmacological modulation, thus providing mechanistic and quantitative insights into compound potency, selectivity, and on-target specificity. We propose that these reporter assays can serve as tools to dissect the interplay of DSBR pathway networks in cells and will have broad implications for studies of DSBR mechanisms in basic research and drug discovery.
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Affiliation(s)
- Eeson Rajendra
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | - Diego Grande
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | - Bethany Mason
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | | | - Lucy Armstrong
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | | | - Elias Elinati
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | | | - Simon J Boulton
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
- The Francis Crick Institute, London NW1 1AT, UK
| | - Robert A Heald
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
| | - Graeme C M Smith
- Artios Pharma Ltd, Babraham Research Campus, Cambridge CB22 3FH, UK
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4
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Tsukada K, Jones SE, Bannister J, Durin MA, Vendrell I, Fawkes M, Fischer R, Kessler BM, Chapman JR, Blackford AN. BLM and BRCA1-BARD1 coordinate complementary mechanisms of joint DNA molecule resolution. Mol Cell 2024; 84:640-658.e10. [PMID: 38266639 DOI: 10.1016/j.molcel.2023.12.040] [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: 03/18/2023] [Revised: 10/10/2023] [Accepted: 12/22/2023] [Indexed: 01/26/2024]
Abstract
The Bloom syndrome helicase BLM interacts with topoisomerase IIIα (TOP3A), RMI1, and RMI2 to form the BTR complex, which dissolves double Holliday junctions and DNA replication intermediates to promote sister chromatid disjunction before cell division. In its absence, structure-specific nucleases like the SMX complex (comprising SLX1-SLX4, MUS81-EME1, and XPF-ERCC1) can cleave joint DNA molecules instead, but cells deficient in both BTR and SMX are not viable. Here, we identify a negative genetic interaction between BLM loss and deficiency in the BRCA1-BARD1 tumor suppressor complex. We show that this is due to a previously overlooked role for BARD1 in recruiting SLX4 to resolve DNA intermediates left unprocessed by BLM in the preceding interphase. Consequently, cells with defective BLM and BRCA1-BARD1 accumulate catastrophic levels of chromosome breakage and micronucleation, leading to cell death. Thus, we reveal mechanistic insights into SLX4 recruitment to DNA lesions, with potential clinical implications for treating BRCA1-deficient tumors.
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Affiliation(s)
- Kaima Tsukada
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Samuel E Jones
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Julius Bannister
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Mary-Anne Durin
- MRC Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Iolanda Vendrell
- Target Discovery Institute, Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK; Chinese Academy for Medical Sciences Oxford Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK
| | - Matthew Fawkes
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Roman Fischer
- Target Discovery Institute, Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK; Chinese Academy for Medical Sciences Oxford Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK
| | - Benedikt M Kessler
- Target Discovery Institute, Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK; Chinese Academy for Medical Sciences Oxford Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK
| | - J Ross Chapman
- MRC Haematology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - Andrew N Blackford
- Department of Oncology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK.
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5
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Sundaresan Y, Yacoub S, Kodati B, Amankwa CE, Raola A, Zode G. Therapeutic applications of CRISPR/Cas9 gene editing technology for the treatment of ocular diseases. FEBS J 2023; 290:5248-5269. [PMID: 36877952 PMCID: PMC10480348 DOI: 10.1111/febs.16771] [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: 05/24/2022] [Revised: 02/04/2023] [Accepted: 03/03/2023] [Indexed: 03/08/2023]
Abstract
Ocular diseases are a highly heterogeneous group of phenotypes, caused by a spectrum of genetic variants and environmental factors that exhibit diverse clinical symptoms. As a result of its anatomical location, structure and immune privilege, the eye is an ideal system to assess and validate novel genetic therapies. Advances in genome editing have revolutionized the field of biomedical science, enabling researchers to understand the biology behind disease mechanisms and allow the treatment of several health conditions, including ocular pathologies. The advent of clustered regularly interspaced short palindromic repeats (CRISPR)-based gene editing facilitates efficient and specific genetic modifications in the nucleic acid sequence, resulting in permanent changes at the genomic level. This approach has advantages over other treatment strategies and is promising for the treatment of various genetic and non-genetic ocular conditions. This review provides an overview of the CRISPR/CRISPR-associated protein 9 (Cas9) system and summarizes recent advances in the therapeutic application of CRISPR/Cas9 for the treatment of various ocular pathologies, as well as future challenges.
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Affiliation(s)
| | | | - Bindu Kodati
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107
| | - Charles E. Amankwa
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107
| | - Akash Raola
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107
| | - Gulab Zode
- Department of Pharmacology and Neuroscience, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107
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6
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Lavi ES, Lin ZP, Ratner ES. Gene expression of non-homologous end-joining pathways in the prognosis of ovarian cancer. iScience 2023; 26:107934. [PMID: 37810216 PMCID: PMC10558711 DOI: 10.1016/j.isci.2023.107934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 04/04/2023] [Accepted: 09/13/2023] [Indexed: 10/10/2023] Open
Abstract
Ovarian cancer is the deadliest gynecologic malignancy in women, with a 46% five-year overall survival rate. The objective of the study was to investigate the effects of non-homologous end-joining (NHEJ) genes on clinical outcomes of ovarian cancer patients. To determine if these genes act as prognostic biomarkers of mortality and disease progression, the expression profiles of 48 NHEJ-associated genes were analyzed using an array of statistical and machine learning techniques: logistic regression models, decision trees, naive-Bayes, two sample t-tests, support vector machines, hierarchical clustering, principal component analysis, and neural networks. In this process, the correlation of genes with patient survival and disease progression and recurrence was noted. Also, multiple features from the gene set were found to have significant predictive capabilities. APTX, BRCA1, PAXX, LIG1, and TP53 were identified as most important out of all the candidate genes for predicting clinical outcomes of ovarian cancer patients.
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Affiliation(s)
- Ethan S. Lavi
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Z. Ping Lin
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Elena S. Ratner
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06510, USA
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7
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Hamaker NK, Lee KH. High-efficiency and multilocus targeted integration in CHO cells using CRISPR-mediated donor nicking and DNA repair inhibitors. Biotechnol Bioeng 2023; 120:2419-2440. [PMID: 37039773 PMCID: PMC10524319 DOI: 10.1002/bit.28393] [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: 11/23/2022] [Revised: 03/20/2023] [Accepted: 03/24/2023] [Indexed: 04/12/2023]
Abstract
Efforts to leverage clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) for targeted genomic modifications in mammalian cells are limited by low efficiencies and heterogeneous outcomes. To aid method optimization, we developed an all-in-one reporter system, including a novel superfolder orange fluorescent protein (sfOrange), to simultaneously quantify gene disruption, site-specific integration (SSI), and random integration (RI). SSI strategies that utilize different donor plasmid formats and Cas9 nuclease variants were evaluated for targeting accuracy and efficiency in Chinese hamster ovary cells. Double-cut and double-nick donor formats significantly improved targeting accuracy by 2.3-8.3-fold and 19-22-fold, respectively, compared to standard circular donors. Notably, Cas9-mediated donor linearization was associated with increased RI events, whereas donor nicking minimized RI without sacrificing SSI efficiency and avoided low-fidelity outcomes. A screen of 10 molecules that modulate the major mammalian DNA repair pathways identified two inhibitors that further enhance targeting accuracy and efficiency to achieve SSI in 25% of transfected cells without selection. The optimized methods integrated transgene expression cassettes with 96% efficiency at a single locus and with 53%-55% efficiency at two loci simultaneously in selected clones. The CRISPR-based tools and methods developed here could inform the use of CRISPR/Cas9 in mammalian cell lines, accelerate mammalian cell line engineering, and support advanced recombinant protein production applications.
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Affiliation(s)
- Nathaniel K. Hamaker
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, 19716, USA
| | - Kelvin H. Lee
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, 19716, USA
- The National Institute for Innovation in Manufacturing Biopharmaceuticals (NIIMBL), University of Delaware, Newark, DE, 19713, USA
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8
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Azambuja DDB, E Gloria HDC, Montenegro GES, Kalil AN, Hoffmann JS, Leguisamo NM, Saffi J. High Expression of MRE11A Is Associated with Shorter Survival and a Higher Risk of Death in CRC Patients. Genes (Basel) 2023; 14:1270. [PMID: 37372450 DOI: 10.3390/genes14061270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
BACKGROUND Homologous recombination repair (HR) is the most accurate repair pathway for double-strand breaks and replication fork disruption that is capable of faithfully restoring the original nucleotide sequence of the broken DNA. The deficiency of this mechanism is a frequent event in tumorigenesis. Therapies that exploit defects in HR have been explored essentially in breast, ovarian, pancreatic, and prostate cancers, but poorly in colorectal cancers (CRC), although CRC ranks second in mortality worldwide. METHODS Tumor specimens and matched healthy tissues from 63 patients with CRC were assessed for gene expression of key HR components and mismatch repair (MMR) status, which correlated with clinicopathological features, progression-free survival, and overall survival (OS). RESULTS Enhanced expression of MRE11 homolog (MRE11A), the gene encoding a key molecular actor for resection, is significantly overexpressed in CRC, is associated with the occurrence of primary tumors, particularly T3-T4, and is found in more than 90% of the right-side of CRC, the location with the worst prognosis. Importantly, we also found that high MRE11A transcript abundance is associated with 16.7 months shorter OS and a 3.5 higher risk of death. CONCLUSION Monitoring of MRE11 expression could be used both as a predictor of outcome and as a marker to select CRC patients for treatments thus far adapted for HR-deficient cancers.
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Affiliation(s)
- Daniel de Barcellos Azambuja
- Laboratório de Genética Toxicológica, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre 90050-170, RS, Brazil
- Hospital Santa Rita, Irmandade Santa Casa de Misericórdia de Porto Alegre (ISCMPA), Porto Alegre 90020-090, RS, Brazil
| | - Helena de Castro E Gloria
- Laboratório de Genética Toxicológica, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre 90050-170, RS, Brazil
| | - Gabriel E Silva Montenegro
- Laboratório de Genética Toxicológica, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre 90050-170, RS, Brazil
| | - Antonio Nocchi Kalil
- Laboratório de Genética Toxicológica, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre 90050-170, RS, Brazil
- Hospital Santa Rita, Irmandade Santa Casa de Misericórdia de Porto Alegre (ISCMPA), Porto Alegre 90020-090, RS, Brazil
| | - Jean-Sébastien Hoffmann
- Laboratoire d'Excellence Toulouse Cancer, Laboratoire de Pathologie, CHU Toulouse, Institut Universitaire du Cancer-Toulouse, Oncopole, 1 Avenue Irène-Joliot-Curie, CEDEX, 31059 Toulouse, France
| | - Natalia Motta Leguisamo
- Laboratório de Genética Toxicológica, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre 90050-170, RS, Brazil
- Hospital Santa Rita, Irmandade Santa Casa de Misericórdia de Porto Alegre (ISCMPA), Porto Alegre 90020-090, RS, Brazil
| | - Jenifer Saffi
- Laboratório de Genética Toxicológica, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre 90050-170, RS, Brazil
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9
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Han W, Li Z, Guo Y, He K, Li W, Xu C, Ge L, He M, Yin X, Zhou J, Li C, Yao D, Bao J, Liang H. Efficient precise integration of large DNA sequences with 3'-overhang dsDNA donors using CRISPR/Cas9. Proc Natl Acad Sci U S A 2023; 120:e2221127120. [PMID: 37216515 PMCID: PMC10235934 DOI: 10.1073/pnas.2221127120] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/18/2023] [Indexed: 05/24/2023] Open
Abstract
CRISPR/Cas9 genome-editing tools have tremendously boosted our capability of manipulating the eukaryotic genomes in biomedical research and innovative biotechnologies. However, the current approaches that allow precise integration of gene-sized large DNA fragments generally suffer from low efficiency and high cost. Herein, we developed a versatile and efficient approach, termed LOCK (Long dsDNA with 3'-Overhangs mediated CRISPR Knock-in), by utilizing specially designed 3'-overhang double-stranded DNA (odsDNA) donors harboring 50-nt homology arm. The length of the 3'-overhangs of odsDNA is specified by the five consecutive phosphorothioate modifications. Compared with existing methods, LOCK allows highly efficient targeted insertion of kilobase-sized DNA fragments into the mammalian genomes with low cost and low off-target effects, yielding >fivefold higher knock-in frequencies than conventional homologous recombination-based approaches. This newly designed LOCK approach based on homology-directed repair is a powerful tool suitable for gene-sized fragment integration that is urgently needed for genetic engineering, gene therapies, and synthetic biology.
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Affiliation(s)
- Wenjie Han
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China230026Hefei, Anhui, China
- School of Chemistry and Materials Science, Department of Polymer Science and Engineering, Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China230026Hefei, Anhui, China
| | - Zhigang Li
- School of Chemistry and Materials Science, Department of Polymer Science and Engineering, Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China230026Hefei, Anhui, China
| | - Yijun Guo
- School of Chemistry and Materials Science, Department of Polymer Science and Engineering, Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China230026Hefei, Anhui, China
| | - Kaining He
- School of Chemistry and Materials Science, Department of Polymer Science and Engineering, Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China230026Hefei, Anhui, China
| | - Wenqing Li
- The First Affiliated Hospital of University of Science and Technology of China, Biomedical Sciences and Health Laboratory of Anhui Province, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China230001Hefei, Anhui, China
| | - Caoling Xu
- The First Affiliated Hospital of University of Science and Technology of China, Biomedical Sciences and Health Laboratory of Anhui Province, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China230001Hefei, Anhui, China
| | - Lishuang Ge
- School of Chemistry and Materials Science, Department of Polymer Science and Engineering, Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China230026Hefei, Anhui, China
| | - Miao He
- School of Chemistry and Materials Science, Department of Polymer Science and Engineering, Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China230026Hefei, Anhui, China
| | - Xue Yin
- School of Chemistry and Materials Science, Department of Polymer Science and Engineering, Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China230026Hefei, Anhui, China
| | - Junxiang Zhou
- School of Chemistry and Materials Science, Department of Polymer Science and Engineering, Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China230026Hefei, Anhui, China
| | - Chengxu Li
- School of Chemistry and Materials Science, Department of Polymer Science and Engineering, Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China230026Hefei, Anhui, China
| | - Dongbao Yao
- School of Chemistry and Materials Science, Department of Polymer Science and Engineering, Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China230026Hefei, Anhui, China
| | - Jianqiang Bao
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China230026Hefei, Anhui, China
- The First Affiliated Hospital of University of Science and Technology of China, Biomedical Sciences and Health Laboratory of Anhui Province, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China230001Hefei, Anhui, China
| | - Haojun Liang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China230026Hefei, Anhui, China
- School of Chemistry and Materials Science, Department of Polymer Science and Engineering, Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China230026Hefei, Anhui, China
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10
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Anuchina AA, Zaynitdinova MI, Demchenko AG, Evtushenko NA, Lavrov AV, Smirnikhina SA. Bridging Gaps in HDR Improvement: The Role of MAD2L2, SCAI, and SCR7. Int J Mol Sci 2023; 24:ijms24076704. [PMID: 37047677 PMCID: PMC10095018 DOI: 10.3390/ijms24076704] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 03/31/2023] [Accepted: 04/01/2023] [Indexed: 04/07/2023] Open
Abstract
This study aimed to enhance homology-directed repair (HDR) efficiency in CRISPR/Cas-mediated genome editing by targeting three key factors regulating the balance between HDR and non-homologous end joining (NHEJ): MAD2L2, SCAI, and Ligase IV. In order to achieve this, a cellular model using mutated eGFP was designed to monitor HDR events. Results showed that MAD2L2 knockdown and SCR7 treatment significantly improved HDR efficiency during Cas9-mediated HDR repair of the mutated eGFP gene in the HEK293T cell line. Fusion protein Cas9-SCAI did not improve HDR. This study is the first to demonstrate that MAD2L2 knockdown during CRISPR-mediated gene editing in HEK293T cells can increase precise correction by up to 10.2 times. The study also confirmed a moderate but consistent effect of SCR7, an inhibitor of Ligase IV, which increased HDR by 1.7 times. These findings provide valuable insights into improving HDR-based genome editing efficiency.
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Affiliation(s)
- Arina A. Anuchina
- Research Centre for Medical Genetics, Moskvorechie 1, 115522 Moscow, Russia
| | | | - Anna G. Demchenko
- Research Centre for Medical Genetics, Moskvorechie 1, 115522 Moscow, Russia
| | - Nadezhda A. Evtushenko
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, Ostrovityanova 1, 117997 Moscow, Russia
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11
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Kinoshita C, Takizawa Y, Saotome M, Ogino S, Kurumizaka H, Kagawa W. The cryo-EM structure of full-length RAD52 protein contains an undecameric ring. FEBS Open Bio 2023; 13:408-418. [PMID: 36707939 PMCID: PMC9989933 DOI: 10.1002/2211-5463.13565] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 12/29/2022] [Accepted: 01/26/2023] [Indexed: 01/29/2023] Open
Abstract
The human RAD52 protein, which forms an oligomeric ring structure, is involved in DNA double-strand break repair. The N-terminal half of RAD52 is primarily responsible for self-oligomerisation and DNA binding. Crystallographic studies have revealed the detailed structure of the N-terminal half. However, only low-resolution structures have been reported for the full-length protein, and thus the structural role of the C-terminal half in self-oligomerisation has remained elusive. In this study, we determined the solution structure of the human RAD52 protein by cryo-electron microscopy (cryo-EM), at an average resolution of 3.5 Å. The structure revealed an undecameric ring that is nearly identical to the crystal structures of the N-terminal half. The cryo-EM map for the C-terminal half was poorly defined, indicating that the region is intrinsically disordered. The present cryo-EM structure provides important insights into the mechanistic roles played by the N-terminal and C-terminal halves of RAD52 during DNA double-strand break repair.
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Affiliation(s)
- Chiaki Kinoshita
- Department of Chemistry, Graduate School of Science and Engineering, Meisei University, Tokyo, Japan
| | - Yoshimasa Takizawa
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Japan
| | - Mika Saotome
- Department of Chemistry, Graduate School of Science and Engineering, Meisei University, Tokyo, Japan
| | - Shun Ogino
- Department of Chemistry, Graduate School of Science and Engineering, Meisei University, Tokyo, Japan
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Japan
| | - Wataru Kagawa
- Department of Chemistry, Graduate School of Science and Engineering, Meisei University, Tokyo, Japan
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12
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Wang C, Chan DW, Hendrickson EA. Kinome-wide screening uncovers a role for Bromodomain Protein 3 in DNA double-stranded break repair. DNA Repair (Amst) 2023; 122:103445. [PMID: 36608404 PMCID: PMC10353298 DOI: 10.1016/j.dnarep.2022.103445] [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: 07/12/2022] [Revised: 12/17/2022] [Accepted: 12/22/2022] [Indexed: 12/25/2022]
Abstract
Double-stranded breaks (DSBs) are toxic DNA damage and a serious threat to genomic integrity. Thus, all living organisms have evolved multiple mechanisms of DNA DSB repair, the two principal ones being classical-non homologous end joining (C-NHEJ), and homology dependent recombination (HDR). In mammals, C-NHEJ is the predominate DSB repair pathway, but how a cell chooses to repair a particular DSB by a certain pathway is still not mechanistically clear. To uncover novel regulators of DSB repair pathway choice, we performed a kinome-wide screen in a human cell line engineered to express a dominant-negative C-NHEJ factor. The intellectual basis for such a screen was our hypothesis that a C-NHEJ-crippled cell line might need to upregulate other DSB repair pathways, including HDR, in order to survive. This screen identified Bromodomain-containing Protein 3 (BRD3) as a protein whose expression was almost completely ablated specifically in a C-NHEJ-defective cell line. Subsequent experimentation demonstrated that BRD3 is a negative regulator of HDR as BRD3-null cell lines proved to be hyper-recombinogenic for gene conversion, sister chromatid exchanges and gene targeting. Mechanistically, BRD3 appears to be working at the level of Radiation Sensitive 51 (RAD51) recruitment. Overall, our results demonstrate that BRD3 is a novel regulator of human DSB repair pathway choice.
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Affiliation(s)
- Chen Wang
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Doug W Chan
- Department of Systems Biology, University of Texas, MD Anderson Cancer Center, Houston, TX, 77030
| | - Eric A Hendrickson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
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13
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Zafar K, Khan MZ, Amin I, Mukhtar Z, Zafar M, Mansoor S. Employing template-directed CRISPR-based editing of the OsALS gene to create herbicide tolerance in Basmati rice. AOB PLANTS 2023; 15:plac059. [PMID: 36873055 PMCID: PMC9977225 DOI: 10.1093/aobpla/plac059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 01/06/2023] [Indexed: 06/18/2023]
Abstract
Rice (Oryza sativa) is one of the primary food crops which contributes major portion of daily calorie intake. It is used as model crop for various genome editing studies. Basmati rice was also explored for establishing non-homologous end joining-based genome editing. But it was not clear whether homology-directed repair (HDR)-based genome editing can be done in Basmati rice. The current study was designed to establish HDR-based genome editing in Basmati rice to develop herbicide tolerance. There is severe weed spread when rice is grown via direct planted rice method in various countries to save labour and water resources. Therefore, the use of herbicides is necessary to control weeds. These herbicides can also affect cultivated rice which creates the need to develop herbicide-tolerant rice. In current study, we introduced a point mutation in Acetolactate Synthase gene to convert tryptophan to leucine at position 548. For this purpose, different constructs for HDR were tested with different RNA scaffold and orientation of repair templates. Out of four different architectures, the one having repair template identical to the target DNA strand precisely edited the target site. We successfully established template-directed CRISPR-Cas9 system in Super Basmati rice by detecting desired substitutions at the target site in Acetolactate Synthase locus. Moreover, this editing of Acetolactate Synthase gene resulted in the production of herbicide tolerance in Super Basmati rice. This study suggests that such type of HDR system can be used to precisely edit other genes for crop improvement.
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Affiliation(s)
| | - Muhammad Zuhaib Khan
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences, Jhang Road, Faisalabad 37000, Pakistan
| | - Imran Amin
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences, Jhang Road, Faisalabad 37000, Pakistan
| | - Zahid Mukhtar
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences, Jhang Road, Faisalabad 37000, Pakistan
| | - Mehak Zafar
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences, Jhang Road, Faisalabad 37000, Pakistan
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14
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Aslan A, Yuka SA. Stem Cell-Based Therapeutic Approaches in Genetic Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1436:19-53. [PMID: 36735185 DOI: 10.1007/5584_2023_761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Stem cells, which can self-renew and differentiate into different cell types, have become the keystone of regenerative medicine due to these properties. With the achievement of superior clinical results in the therapeutic approaches of different diseases, the applications of these cells in the treatment of genetic diseases have also come to the fore. Foremost, conventional approaches of stem cells to genetic diseases are the first approaches in this manner, and they have brought safety issues due to immune reactions caused by allogeneic transplantation. To eliminate these safety issues and phenotypic abnormalities caused by genetic defects, firstly, basic genetic engineering practices such as vectors or RNA modulators were combined with stem cell-based therapeutic approaches. However, due to challenges such as immune reactions and inability to target cells effectively in these applications, advanced molecular methods have been adopted in ZFN, TALEN, and CRISPR/Cas genome editing nucleases, which allow modular designs in stem cell-based genetic diseases' therapeutic approaches. Current studies in genetic diseases are in the direction of creating permanent treatment regimens by genomic manipulation of stem cells with differentiation potential through genome editing tools. In this chapter, the stem cell-based therapeutic approaches of various vital genetic diseases were addressed wide range from conventional applications to genome editing tools.
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Affiliation(s)
- Ayça Aslan
- Department of Bioengineering, Yildiz Technical University, Istanbul, Turkey
| | - Selcen Arı Yuka
- Department of Bioengineering, Yildiz Technical University, Istanbul, Turkey.
- Health Biotechnology Joint Research and Application Center of Excellence, Istanbul, Turkey.
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15
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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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16
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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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17
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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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18
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Small-molecule enhancers of CRISPR-induced homology-directed repair in gene therapy: A medicinal chemist's perspective. Drug Discov Today 2022; 27:2510-2525. [PMID: 35738528 DOI: 10.1016/j.drudis.2022.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/19/2022] [Accepted: 06/16/2022] [Indexed: 11/20/2022]
Abstract
CRISPR technologies are increasingly being investigated and utilized for the treatment of human genetic diseases via genome editing. CRISPR-Cas9 first generates a targeted DNA double-stranded break, and a functional gene can then be introduced to replace the defective copy in a precise manner by templated repair via the homology-directed repair (HDR) pathway. However, this is challenging owing to the relatively low efficiency of the HDR pathway compared with a rival random repair pathway known as non-homologous end joining (NHEJ). Small molecules can be employed to increase the efficiency of HDR and decrease that of NHEJ to improve the efficiency of precise knock-in genome editing. This review discusses the potential usage of such small molecules in the context of gene therapy and their drug-likeness, from a medicinal chemist's perspective.
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19
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Xu X, Harvey-Samuel T, Siddiqui HA, Ang JXD, Anderson ME, Reitmayer CM, Lovett E, Leftwich PT, You M, Alphey L. Toward a CRISPR-Cas9-based Gene Drive in the Diamondback Moth Plutella xylostella. CRISPR J 2022; 5:224-236. [PMID: 35285719 DOI: 10.1089/crispr.2021.0129] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Promising to provide powerful genetic control tools, gene drives have been constructed in multiple dipteran insects, yeast, and mice for the purposes of population elimination or modification. However, it remains unclear whether these techniques can be applied to lepidopterans. Here, we used endogenous regulatory elements to drive Cas9 and single guide RNA (sgRNA) expression in the diamondback moth (DBM), Plutella xylostella, and test the first split gene drive system in a lepidopteran. The DBM is an economically important global agriculture pest of cruciferous crops and has developed severe resistance to various insecticides, making it a prime candidate for such novel control strategy development. A very high level of somatic editing was observed in Cas9/sgRNA transheterozygotes, although no significant homing was revealed in the subsequent generation. Although heritable Cas9-medated germline cleavage as well as maternal and paternal Cas9 deposition were observed, rates were far lower than for somatic cleavage events, indicating robust somatic but limited germline activity of Cas9/sgRNA under the control of selected regulatory elements. Our results provide valuable experience, paving the way for future construction of gene drives or other Cas9-based genetic control strategies in DBM and other lepidopterans.
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Affiliation(s)
- Xuejiao Xu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, P.R. China.,School of Life Sciences, Peking University, Beijing, P.R. China
| | - Tim Harvey-Samuel
- Arthropod Genetics Group, The Pirbright Institute, Woking, Pirbright, United Kingdom
| | - Hamid Anees Siddiqui
- National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
| | - Joshua Xin De Ang
- Arthropod Genetics Group, The Pirbright Institute, Woking, Pirbright, United Kingdom
| | | | - Christine M Reitmayer
- Arthropod Genetics Group, The Pirbright Institute, Woking, Pirbright, United Kingdom
| | - Erica Lovett
- Arthropod Genetics Group, The Pirbright Institute, Woking, Pirbright, United Kingdom
| | - Philip T Leftwich
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Minsheng You
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, P.R. China
| | - Luke Alphey
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, P.R. China.,Arthropod Genetics Group, The Pirbright Institute, Woking, Pirbright, United Kingdom
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20
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Rezazade Bazaz M, Dehghani H. From DNA break repair pathways to CRISPR/Cas-mediated gene knock-in methods. Life Sci 2022; 295:120409. [PMID: 35182556 DOI: 10.1016/j.lfs.2022.120409] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 12/11/2022]
Abstract
Various DNA breaks created via programmable CRISPR/Cas9 nuclease activity results in different intracellular DNA break repair pathways. Based on the cellular repair pathways, CRISPR-based gene knock-in methods can be categorized into two major strategies: 1) Homology-independent strategies which are targeted insertion events based on non-homologous end joining, and 2) Homology-dependent strategies which are targeted insertion events based on the homology-directed repair. This review elaborates on various gene knock-in methods in mammalian cells using the CRISPR/Cas9 system and in sync with DNA-break repair pathways. Gene knock-in methods are applied in functional genomics and gene therapy. To compensate or correct genetic defects, different CRISPR-based gene knock-in strategies can be used. Thus, researchers need to make a conscious decision about the most suitable knock-in method. For a successful gene-targeted insertion, some determinant factors should be considered like cell cycle, dominant DNA repair pathway, size of insertions, and donor properties. In this review, different aspects of each gene knock-in strategy are discussed to provide a framework for choosing the most appropriate gene knock-in method in different applications.
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Affiliation(s)
- Mahere Rezazade Bazaz
- Division of Biotechnology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran; Stem Cell Biology and Regenerative Medicine Research Group, Research Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Hesam Dehghani
- Division of Biotechnology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran; Stem Cell Biology and Regenerative Medicine Research Group, Research Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran; Department of Basic Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran.
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21
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Ramsden DA, Carvajal-Garcia J, Gupta GP. Mechanism, cellular functions and cancer roles of polymerase-theta-mediated DNA end joining. Nat Rev Mol Cell Biol 2022; 23:125-140. [PMID: 34522048 DOI: 10.1038/s41580-021-00405-2] [Citation(s) in RCA: 87] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2021] [Indexed: 02/08/2023]
Abstract
Cellular pathways that repair chromosomal double-strand breaks (DSBs) have pivotal roles in cell growth, development and cancer. These DSB repair pathways have been the target of intensive investigation, but one pathway - alternative end joining (a-EJ) - has long resisted elucidation. In this Review, we highlight recent progress in our understanding of a-EJ, especially the assignment of DNA polymerase theta (Polθ) as the predominant mediator of a-EJ in most eukaryotes, and discuss a potential molecular mechanism by which Polθ-mediated end joining (TMEJ) occurs. We address possible cellular functions of TMEJ in resolving DSBs that are refractory to repair by non-homologous end joining (NHEJ), DSBs generated following replication fork collapse and DSBs present owing to stalling of repair by homologous recombination. We also discuss how these context-dependent cellular roles explain how TMEJ can both protect against and cause genome instability, and the emerging potential of Polθ as a therapeutic target in cancer.
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Affiliation(s)
- Dale A Ramsden
- Lineberger Comprehensive Cancer Center, 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.
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Juan Carvajal-Garcia
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Gaorav P Gupta
- Lineberger Comprehensive Cancer Center, 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.
- 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.
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22
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Hausmann M, Hildenbrand G, Pilarczyk G. Networks and Islands of Genome Nano-architecture and Their Potential Relevance for Radiation Biology : (A Hypothesis and Experimental Verification Hints). Results Probl Cell Differ 2022; 70:3-34. [PMID: 36348103 DOI: 10.1007/978-3-031-06573-6_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The cell nucleus is a complex biological system in which simultaneous reactions and functions take place to keep the cell as an individualized, specialized system running well. The cell nucleus contains chromatin packed in various degrees of density and separated in volumes of chromosome territories and subchromosomal domains. Between the chromatin, however, there is enough "free" space for floating RNA, proteins, enzymes, ATPs, ions, water molecules, etc. which are trafficking by super- and supra-diffusion to the interaction points where they are required. It seems that this trafficking works somehow automatically and drives the system perfectly. After exposure to ionizing radiation causing DNA damage from single base damage up to chromatin double-strand breaks, the whole system "cell nucleus" responds, and repair processes are starting to recover the fully functional and intact system. In molecular biology, many individual epigenetic pathways of DNA damage response or repair of single and double-strand breaks are described. How these responses are embedded into the response of the system as a whole is often out of the focus of consideration. In this article, we want to follow the hypothesis of chromatin architecture's impact on epigenetic pathways and vice versa. Based on the assumption that chromatin acts like an "aperiodic solid state within a limited volume," functionally determined networks and local topologies ("islands") can be defined that drive the appropriate repair process at a given damage site. Experimental results of investigations of the chromatin nano-architecture and DNA repair clusters obtained by means of single-molecule localization microscopy offer hints and perspectives that may contribute to verifying the hypothesis.
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Affiliation(s)
- Michael Hausmann
- Kirchhoff-Institute for Physics, Heidelberg University, Heidelberg, Germany.
| | - Georg Hildenbrand
- Kirchhoff-Institute for Physics, Heidelberg University, Heidelberg, Germany
| | - Götz Pilarczyk
- Kirchhoff-Institute for Physics, Heidelberg University, Heidelberg, Germany
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23
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Smirnov A, Battulin N. Concatenation of Transgenic DNA: Random or Orchestrated? Genes (Basel) 2021; 12:genes12121969. [PMID: 34946918 PMCID: PMC8701086 DOI: 10.3390/genes12121969] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/08/2021] [Accepted: 12/09/2021] [Indexed: 12/18/2022] Open
Abstract
Generation of transgenic organisms by pronuclear microinjection has become a routine procedure. However, while the process of DNA integration in the genome is well understood, we still do not know much about the recombination between transgene molecules that happens in the first moments after DNA injection. Most of the time, injected molecules are joined together in head-to-tail tandem repeats-the so-called concatemers. In this review, we focused on the possible concatenation mechanisms and how they could be studied with genetic reporters tracking individual copies in concatemers. We also discuss various features of concatemers, including palindromic junctions and repeat-induced gene silencing (RIGS). Finally, we speculate how cooperation of DNA repair pathways creates a multicopy concatenated insert.
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Affiliation(s)
- Alexander Smirnov
- Laboratory of Developmental Genetics, Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia;
| | - Nariman Battulin
- Laboratory of Developmental Genetics, Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia;
- Institute of Genetic Technologies, Novosibirsk State University, 630090 Novosibirsk, Russia
- Correspondence:
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24
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Impact of Chromatin Dynamics and DNA Repair on Genomic Stability and Treatment Resistance in Pediatric High-Grade Gliomas. Cancers (Basel) 2021; 13:cancers13225678. [PMID: 34830833 PMCID: PMC8616465 DOI: 10.3390/cancers13225678] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/08/2021] [Accepted: 11/11/2021] [Indexed: 02/07/2023] Open
Abstract
Simple Summary Pediatric high-grade gliomas (pHGGs) are the leading cause of mortality in pediatric neuro-oncology, due in great part to treatment resistance driven by complex DNA repair mechanisms. pHGGs have recently been divided into molecular subtypes based on mutations affecting the N-terminal tail of the histone variant H3.3 and the ATRX/DAXX histone chaperone that deposits H3.3 at repetitive heterochromatin loci that are of paramount importance to the stability of our genome. This review addresses the functions of H3.3 and ATRX/DAXX in chromatin dynamics and DNA repair, as well as the impact of mutations affecting H3.3/ATRX/DAXX on treatment resistance and how the vulnerabilities they expose could foster novel therapeutic strategies. Abstract Despite their low incidence, pediatric high-grade gliomas (pHGGs), including diffuse intrinsic pontine gliomas (DIPGs), are the leading cause of mortality in pediatric neuro-oncology. Recurrent, mutually exclusive mutations affecting K27 (K27M) and G34 (G34R/V) in the N-terminal tail of histones H3.3 and H3.1 act as key biological drivers of pHGGs. Notably, mutations in H3.3 are frequently associated with mutations affecting ATRX and DAXX, which encode a chaperone complex that deposits H3.3 into heterochromatic regions, including telomeres. The K27M and G34R/V mutations lead to distinct epigenetic reprogramming, telomere maintenance mechanisms, and oncogenesis scenarios, resulting in distinct subgroups of patients characterized by differences in tumor localization, clinical outcome, as well as concurrent epigenetic and genetic alterations. Contrasting with our understanding of the molecular biology of pHGGs, there has been little improvement in the treatment of pHGGs, with the current mainstays of therapy—genotoxic chemotherapy and ionizing radiation (IR)—facing the development of tumor resistance driven by complex DNA repair pathways. Chromatin and nucleosome dynamics constitute important modulators of the DNA damage response (DDR). Here, we summarize the major DNA repair pathways that contribute to resistance to current DNA damaging agent-based therapeutic strategies and describe the telomere maintenance mechanisms encountered in pHGGs. We then review the functions of H3.3 and its chaperones in chromatin dynamics and DNA repair, as well as examining the impact of their mutation/alteration on these processes. Finally, we discuss potential strategies targeting DNA repair and epigenetic mechanisms as well as telomere maintenance mechanisms, to improve the treatment of pHGGs.
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25
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Sanchez A, Lee D, Kim DI, Miller KM. Making Connections: Integrative Signaling Mechanisms Coordinate DNA Break Repair in Chromatin. Front Genet 2021; 12:747734. [PMID: 34659365 PMCID: PMC8514019 DOI: 10.3389/fgene.2021.747734] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 08/31/2021] [Indexed: 01/25/2023] Open
Abstract
DNA double-strand breaks (DSBs) are hazardous to genome integrity and can promote mutations and disease if not handled correctly. Cells respond to these dangers by engaging DNA damage response (DDR) pathways that are able to identify DNA breaks within chromatin leading ultimately to their repair. The recognition and repair of DSBs by the DDR is largely dependent on the ability of DNA damage sensing factors to bind to and interact with nucleic acids, nucleosomes and their modified forms to target these activities to the break site. These contacts orientate and localize factors to lesions within chromatin, allowing signaling and faithful repair of the break to occur. Coordinating these events requires the integration of several signaling and binding events. Studies are revealing an enormously complex array of interactions that contribute to DNA lesion recognition and repair including binding events on DNA, as well as RNA, RNA:DNA hybrids, nucleosomes, histone and non-histone protein post-translational modifications and protein-protein interactions. Here we examine several DDR pathways that highlight and provide prime examples of these emerging concepts. A combination of approaches including genetic, cellular, and structural biology have begun to reveal new insights into the molecular interactions that govern the DDR within chromatin. While many questions remain, a clearer picture has started to emerge for how DNA-templated processes including transcription, replication and DSB repair are coordinated. Multivalent interactions with several biomolecules serve as key signals to recruit and orientate proteins at DNA lesions, which is essential to integrate signaling events and coordinate the DDR within the milieu of the nucleus where competing genome functions take place. Genome architecture, chromatin structure and phase separation have emerged as additional vital regulatory mechanisms that also influence genome integrity pathways including DSB repair. Collectively, recent advancements in the field have not only provided a deeper understanding of these fundamental processes that maintain genome integrity and cellular homeostasis but have also started to identify new strategies to target deficiencies in these pathways that are prevalent in human diseases including cancer.
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Affiliation(s)
- Anthony Sanchez
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, United States.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States
| | - Doohyung Lee
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, United States.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States
| | - Dae In Kim
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, United States.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States
| | - Kyle M Miller
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, United States.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States.,Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, TX, United States
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26
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Zatreanu D, Robinson HMR, Alkhatib O, Boursier M, Finch H, Geo L, Grande D, Grinkevich V, Heald RA, Langdon S, Majithiya J, McWhirter C, Martin NMB, Moore S, Neves J, Rajendra E, Ranzani M, Schaedler T, Stockley M, Wiggins K, Brough R, Sridhar S, Gulati A, Shao N, Badder LM, Novo D, Knight EG, Marlow R, Haider S, Callen E, Hewitt G, Schimmel J, Prevo R, Alli C, Ferdinand A, Bell C, Blencowe P, Bot C, Calder M, Charles M, Curry J, Ekwuru T, Ewings K, Krajewski W, MacDonald E, McCarron H, Pang L, Pedder C, Rigoreau L, Swarbrick M, Wheatley E, Willis S, Wong AC, Nussenzweig A, Tijsterman M, Tutt A, Boulton SJ, Higgins GS, Pettitt SJ, Smith GCM, Lord CJ. Polθ inhibitors elicit BRCA-gene synthetic lethality and target PARP inhibitor resistance. Nat Commun 2021; 12:3636. [PMID: 34140467 PMCID: PMC8211653 DOI: 10.1038/s41467-021-23463-8] [Citation(s) in RCA: 169] [Impact Index Per Article: 56.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 04/30/2021] [Indexed: 02/05/2023] Open
Abstract
To identify approaches to target DNA repair vulnerabilities in cancer, we discovered nanomolar potent, selective, low molecular weight (MW), allosteric inhibitors of the polymerase function of DNA polymerase Polθ, including ART558. ART558 inhibits the major Polθ-mediated DNA repair process, Theta-Mediated End Joining, without targeting Non-Homologous End Joining. In addition, ART558 elicits DNA damage and synthetic lethality in BRCA1- or BRCA2-mutant tumour cells and enhances the effects of a PARP inhibitor. Genetic perturbation screening revealed that defects in the 53BP1/Shieldin complex, which cause PARP inhibitor resistance, result in in vitro and in vivo sensitivity to small molecule Polθ polymerase inhibitors. Mechanistically, ART558 increases biomarkers of single-stranded DNA and synthetic lethality in 53BP1-defective cells whilst the inhibition of DNA nucleases that promote end-resection reversed these effects, implicating these in the synthetic lethal mechanism-of-action. Taken together, these observations describe a drug class that elicits BRCA-gene synthetic lethality and PARP inhibitor synergy, as well as targeting a biomarker-defined mechanism of PARPi-resistance.
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Affiliation(s)
- Diana Zatreanu
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Helen M R Robinson
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Omar Alkhatib
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Marie Boursier
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Harry Finch
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Lerin Geo
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Diego Grande
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Vera Grinkevich
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Robert A Heald
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Sophie Langdon
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Jayesh Majithiya
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Claire McWhirter
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Niall M B Martin
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Shaun Moore
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Joana Neves
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Eeson Rajendra
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Marco Ranzani
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Theresia Schaedler
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Martin Stockley
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Kimberley Wiggins
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
| | - Rachel Brough
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Sandhya Sridhar
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Aditi Gulati
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Nan Shao
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Luned M Badder
- The Breast Cancer Now Research Unit, King's College London, London, UK
| | - Daniela Novo
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Eleanor G Knight
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Rebecca Marlow
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Research Unit, King's College London, London, UK
| | - Syed Haider
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
| | - Elsa Callen
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA
| | | | - Joost Schimmel
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Remko Prevo
- Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, UK
| | - Christina Alli
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Amanda Ferdinand
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Cameron Bell
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Peter Blencowe
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Chris Bot
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Mathew Calder
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Mark Charles
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Jayne Curry
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Tennyson Ekwuru
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Katherine Ewings
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Wojciech Krajewski
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Ellen MacDonald
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Hollie McCarron
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Leon Pang
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Chris Pedder
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Laurent Rigoreau
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Martin Swarbrick
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Ed Wheatley
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Simon Willis
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Ai Ching Wong
- Cancer Research UK, Therapeutic Discovery Laboratories, Jonas Webb Building, Babraham Research Campus, Cambridge, UK
| | - Andre Nussenzweig
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Marcel Tijsterman
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Andrew Tutt
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK
- The Breast Cancer Now Research Unit, King's College London, London, UK
| | - Simon J Boulton
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK
- The Francis Crick Institute, London, UK
| | - Geoff S Higgins
- Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, UK
| | - Stephen J Pettitt
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK.
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK.
| | - Graeme C M Smith
- Artios Pharma, The Glenn Berge Building, Babraham Research Campus, Cambridge, UK.
| | - Christopher J Lord
- CRUK Gene Function Laboratory, The Institute of Cancer Research, London, UK.
- The Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research, London, UK.
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Abstract
Homologous recombination (HR) repairs DNA double-strand breaks by using a homologous template to retrieve sequence information lost at the break site. The broken DNA molecule first engages with the homologous donor molecule and is then separated from it to complete the process. Depending on the HR subpathways used, the separation step can lead to crossovers (COs) between the participating molecules. Such events can cause genomic alterations and eventually cancer if a donor molecule other than the identical sister chromatid is used. Here, we characterize two subpathways of HR with different propensities to form COs. We show the unexpected dominance of the CO-forming subpathway and characterize the processes involved in CO formation and subpathway choice in cancer and normal, untransformed cells. Homologous recombination (HR) is an important DNA double-strand break (DSB) repair pathway that copies sequence information lost at the break site from an undamaged homologous template. This involves the formation of a recombination structure that is processed to restore the original sequence but also harbors the potential for crossover (CO) formation between the participating molecules. Synthesis-dependent strand annealing (SDSA) is an HR subpathway that prevents CO formation and is thought to predominate in mammalian cells. The chromatin remodeler ATRX promotes an alternative HR subpathway that has the potential to form COs. Here, we show that ATRX-dependent HR outcompetes RECQ5-dependent SDSA for the repair of most two-ended DSBs in human cells and leads to the frequent formation of COs, assessed by measuring sister chromatid exchanges (SCEs). We provide evidence that subpathway choice is dependent on interaction of both ATRX and RECQ5 with proliferating cell nuclear antigen. We also show that the subpathway usage varies among different cancer cell lines and compare it to untransformed cells. We further observe HR intermediates arising as ionizing radiation (IR)-induced ultra-fine bridges only in cells expressing ATRX and lacking MUS81 and GEN1. Consistently, damage-induced MUS81 recruitment is only observed in ATRX-expressing cells. Cells lacking BLM show similar MUS81 recruitment and IR-induced SCE formation as control cells. Collectively, these results suggest that the ATRX pathway involves the formation of HR intermediates whose processing is entirely dependent on MUS81 and GEN1 and independent of BLM. We propose that the predominant ATRX-dependent HR subpathway forms joint molecules distinct from classical Holliday junctions.
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28
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Stok C, Kok Y, van den Tempel N, van Vugt MATM. Shaping the BRCAness mutational landscape by alternative double-strand break repair, replication stress and mitotic aberrancies. Nucleic Acids Res 2021; 49:4239-4257. [PMID: 33744950 PMCID: PMC8096281 DOI: 10.1093/nar/gkab151] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 02/18/2021] [Accepted: 03/05/2021] [Indexed: 12/16/2022] Open
Abstract
Tumours with mutations in the BRCA1/BRCA2 genes have impaired double-stranded DNA break repair, compromised replication fork protection and increased sensitivity to replication blocking agents, a phenotype collectively known as 'BRCAness'. Tumours with a BRCAness phenotype become dependent on alternative repair pathways that are error-prone and introduce specific patterns of somatic mutations across the genome. The increasing availability of next-generation sequencing data of tumour samples has enabled identification of distinct mutational signatures associated with BRCAness. These signatures reveal that alternative repair pathways, including Polymerase θ-mediated alternative end-joining and RAD52-mediated single strand annealing are active in BRCA1/2-deficient tumours, pointing towards potential therapeutic targets in these tumours. Additionally, insight into the mutations and consequences of unrepaired DNA lesions may also aid in the identification of BRCA-like tumours lacking BRCA1/BRCA2 gene inactivation. This is clinically relevant, as these tumours respond favourably to treatment with DNA-damaging agents, including PARP inhibitors or cisplatin, which have been successfully used to treat patients with BRCA1/2-defective tumours. In this review, we aim to provide insight in the origins of the mutational landscape associated with BRCAness by exploring the molecular biology of alternative DNA repair pathways, which may represent actionable therapeutic targets in in these cells.
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Affiliation(s)
- Colin Stok
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
| | - Yannick P Kok
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
| | - Nathalie van den Tempel
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
| | - Marcel A T M van Vugt
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
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29
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Abstract
Tumor metastasis is a singularly important determinant of survival in most cancers. Historically, radiation therapy (RT) directed at a primary tumor mass was associated infrequently with remission of metastasis outside the field of irradiation. This away-from-target or "abscopal effect" received fringe attention because of its rarity. With the advent of immunotherapy, there are now increasing reports of abscopal effects upon RT in combination with immune checkpoint inhibition. This sparked investigation into underlying mechanisms and clinical trials aimed at enhancement of this effect. While these studies clearly attribute the abscopal effect to an antitumor immune response, the initial molecular triggers for its onset and specificity remain enigmatic. Here, we propose that DNA damage-induced inflammation coupled with neoantigen generation is essential during this intriguing phenomenon of systemic tumor regression and discuss the implications of this model for treatment aimed at triggering the abscopal effect in metastatic cancer.
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30
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Koussa NC, Smith DJ. Limiting DNA polymerase delta alters replication dynamics and leads to a dependence on checkpoint activation and recombination-mediated DNA repair. PLoS Genet 2021; 17:e1009322. [PMID: 33493195 PMCID: PMC7861531 DOI: 10.1371/journal.pgen.1009322] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 02/04/2021] [Accepted: 12/23/2020] [Indexed: 12/20/2022] Open
Abstract
DNA polymerase delta (Pol δ) plays several essential roles in eukaryotic DNA replication and repair. At the replication fork, Pol δ is responsible for the synthesis and processing of the lagging-strand. At replication origins, Pol δ has been proposed to initiate leading-strand synthesis by extending the first Okazaki fragment. Destabilizing mutations in human Pol δ subunits cause replication stress and syndromic immunodeficiency. Analogously, reduced levels of Pol δ in Saccharomyces cerevisiae lead to pervasive genome instability. Here, we analyze how the depletion of Pol δ impacts replication origin firing and lagging-strand synthesis during replication elongation in vivo in S. cerevisiae. By analyzing nascent lagging-strand products, we observe a genome-wide change in both the establishment and progression of replication. S-phase progression is slowed in Pol δ depletion, with both globally reduced origin firing and slower replication progression. We find that no polymerase other than Pol δ is capable of synthesizing a substantial amount of lagging-strand DNA, even when Pol δ is severely limiting. We also characterize the impact of impaired lagging-strand synthesis on genome integrity and find increased ssDNA and DNA damage when Pol δ is limiting; these defects lead to a strict dependence on checkpoint signaling and resection-mediated repair pathways for cellular viability.
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Affiliation(s)
- Natasha C. Koussa
- Department of Biology, New York University, New York City, New York, United State of America
| | - Duncan J. Smith
- Department of Biology, New York University, New York City, New York, United State of America
- * E-mail:
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31
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Yang Y, Wang T, Yu Q, Liu H, Xun L, Xia Y. The pathway of recombining short homologous ends in Escherichia coli revealed by the genetic study. Mol Microbiol 2021; 115:1309-1322. [PMID: 33372330 DOI: 10.1111/mmi.14677] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/17/2020] [Accepted: 12/23/2020] [Indexed: 11/30/2022]
Abstract
The recombination of short homologous ends in Escherichia coli has been known for 30 years, and it is often used for both site-directed mutagenesis and in vivo cloning. For cloning, a plasmid and target DNA fragments were converted into linear DNA fragments with short homologous ends, which are joined via recombination inside E. coli after transformation. Here this mechanism of joining homologous ends in E. coli was determined by a linearized plasmid with short homologous ends. Two 3'-5' exonucleases ExoIII and ExoX with nonprocessive activity digested linear dsDNA to generate 5' single-strand overhangs, which annealed with each other. The polymerase activity of DNA polymerase I (Pol I) was exclusively employed to fill in the gaps. The strand displacement activity and the 5'-3' exonuclease activity of Pol I were also required, likely to generate 5' phosphate termini for subsequent ligation. Ligase A (LigA) joined the nicks to finish the process. The model involving 5' single-stranded overhangs is different from established recombination pathways that all generate 3' single-stranded overhangs. This recombination is likely common in bacteria since the involved enzymes are ubiquitous.
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Affiliation(s)
- Yuqing Yang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, People's Republic of China.,Institute of Marine Science and Technology, Shandong University, Qingdao, People's Republic of China
| | - Tianqi Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, People's Republic of China
| | - Qiaoli Yu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, People's Republic of China
| | - Huaiwei Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, People's Republic of China
| | - Luying Xun
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, People's Republic of China.,School of Molecular Biosciences, Washington State University, Pullman, WA, USA
| | - Yongzhen Xia
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, People's Republic of China
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32
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Jenkins T, Northall SJ, Ptchelkine D, Lever R, Cubbon A, Betts H, Taresco V, Cooper CDO, McHugh PJ, Soultanas P, Bolt EL. The HelQ human DNA repair helicase utilizes a PWI-like domain for DNA loading through interaction with RPA, triggering DNA unwinding by the HelQ helicase core. NAR Cancer 2021; 3:zcaa043. [PMID: 34316696 PMCID: PMC8210318 DOI: 10.1093/narcan/zcaa043] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/30/2020] [Accepted: 12/16/2020] [Indexed: 01/04/2023] Open
Abstract
Genome instability is a characteristic enabling factor for carcinogenesis. HelQ helicase is a component of human DNA maintenance systems that prevent or reverse genome instability arising during DNA replication. Here, we provide details of the molecular mechanisms that underpin HelQ function-its recruitment onto ssDNA through interaction with replication protein A (RPA), and subsequent translocation of HelQ along ssDNA. We describe for the first time a functional role for the non-catalytic N-terminal region of HelQ, by identifying and characterizing its PWI-like domain. We present evidence that this domain of HelQ mediates interaction with RPA that orchestrates loading of the helicase domains onto ssDNA. Once HelQ is loaded onto the ssDNA, ATP-Mg2+ binding in the catalytic site activates the helicase core and triggers translocation along ssDNA as a dimer. Furthermore, we identify HelQ-ssDNA interactions that are critical for the translocation mechanism. Our data are novel and detailed insights into the mechanisms of HelQ function relevant for understanding how human cells avoid genome instability provoking cancers, and also how cells can gain resistance to treatments that rely on DNA crosslinking agents.
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Affiliation(s)
- Tabitha Jenkins
- School of Life Sciences, The University of Nottingham, NG7 2UH, Nottingham, UK
| | - Sarah J Northall
- School of Life Sciences, The University of Nottingham, NG7 2UH, Nottingham, UK
| | | | - Rebecca Lever
- School of Life Sciences, The University of Nottingham, NG7 2UH, Nottingham, UK
| | - Andrew Cubbon
- School of Life Sciences, The University of Nottingham, NG7 2UH, Nottingham, UK
| | - Hannah Betts
- School of Chemistry, The University of Nottingham, NG7 2RD, Nottingham, UK
| | - Vincenzo Taresco
- School of Pharmacy, The University of Nottingham, NG7 2RD, Nottingham, UK
| | - Christopher D O Cooper
- Department of Biological and Geographical Sciences, School of Applied Sciences, The University of Huddersfield, HD1 3DH, Huddersfield, UK
| | - Peter J McHugh
- MRC Weatherall Institute of Molecular Medicine (WIMM), University of Oxford, OX3 9DS, Oxford, UK
| | - Panos Soultanas
- School of Chemistry, The University of Nottingham, NG7 2RD, Nottingham, UK
| | - Edward L Bolt
- School of Life Sciences, The University of Nottingham, NG7 2UH, Nottingham, UK
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33
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Abstract
Homologous recombination is a conserved genome maintenance pathway through which DNA double-strand breaks are eliminated and perturbed DNA replication forks and eroded telomeres are restored. The central step in homologous recombination is homology-dependent pairing between a single-stranded DNA tail with an intact duplex molecule to generate a displacement-loop (D-loop), followed by DNA synthesis within the D-loop platform. This chapter describes biochemical assays for (1) D-loop formation and DNA synthesis within the D-loop and (2) DNA strand displacement synthesis to test the role of DNA helicases (e.g., Pif1) in repair DNA synthesis. These mechanistic assays are valuable for elucidating the molecular details of HR.
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Wang J, Oh YT, Li Z, Dou J, Tang S, Wang X, Wang H, Takeda S, Wang Y. RAD52 Adjusts Repair of Single-Strand Breaks via Reducing DNA-Damage-Promoted XRCC1/LIG3α Co-localization. Cell Rep 2021; 34:108625. [PMID: 33440161 PMCID: PMC7872142 DOI: 10.1016/j.celrep.2020.108625] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/20/2020] [Accepted: 12/17/2020] [Indexed: 11/07/2022] Open
Abstract
Radiation sensitive 52 (RAD52) is an important factor for double-strand break repair (DSBR). However, deficiency in vertebrate/mammalian Rad52 has no apparent phenotype. The underlying mechanism remains elusive. Here, we report that RAD52 deficiency increased cell survival after camptothecin (CPT) treatment. CPT generates single-strand breaks (SSBs) that further convert to double-strand breaks (DSBs) if they are not repaired. RAD52 inhibits SSB repair (SSBR) through strong single-strand DNA (ssDNA) and/or poly(ADP-ribose) (PAR) binding affinity to reduce DNA-damage-promoted X-Ray Repair Cross Complementing 1 (XRCC1)/ligase IIIα (LIG3α) co-localization. The inhibitory effects of RAD52 on SSBR neutralize the role of RAD52 in DSBR, suggesting that RAD52 may maintain a balance between cell survival and genomic integrity. Furthermore, we demonstrate that blocking RAD52 oligomerization that disrupts RAD52’s DSBR, while retaining its ssDNA binding capacity that is required for RAD52’s inhibitory effects on SSBR, sensitizes cells to different DNA-damaging agents. This discovery provides guidance for developing efficient RAD52 inhibitors in cancer therapy. Wang et al. show that vertebrate/mammalian RAD52 promotes CPT-induced cell death via inhibition of PARP-mediated SSBR, which involves RAD52’s strong ssDNA/PAR binding affinity that reduces DNA-damage-promoted XRCC1-LIG3a interaction. Blocking of RAD52 oligomerization, while retaining the ssDNA binding capacity of RAD52, efficiently sensitizes cells to different DNA-damaging agents.
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Affiliation(s)
- Jian Wang
- Department of Radiation Oncology, Emory University School of Medicine and the Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA
| | - You-Take Oh
- Department of Radiation Oncology, Emory University School of Medicine and the Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA
| | - Zhentian Li
- Department of Radiation Oncology, Emory University School of Medicine and the Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA
| | - Juan Dou
- Department of Radiation Oncology, Emory University School of Medicine and the Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA
| | - Siyuan Tang
- Department of Radiation Oncology, Emory University School of Medicine and the Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA
| | - Xiang Wang
- Department of Radiation Oncology, Emory University School of Medicine and the Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA
| | - Hongyan Wang
- Department of Radiation Oncology, Emory University School of Medicine and the Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA
| | - Shunichi Takeda
- CREST Research Project, Radiation Genetics, Faculty of Medicine, Kyoto University, Yoshida-konoe, Sakyo-ku, Kyoto 606-8501, Japan.
| | - Ya Wang
- Department of Radiation Oncology, Emory University School of Medicine and the Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA.
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Falk M, Hausmann M. A Paradigm Revolution or Just Better Resolution-Will Newly Emerging Superresolution Techniques Identify Chromatin Architecture as a Key Factor in Radiation-Induced DNA Damage and Repair Regulation? Cancers (Basel) 2020; 13:E18. [PMID: 33374540 PMCID: PMC7793109 DOI: 10.3390/cancers13010018] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 12/18/2020] [Indexed: 02/07/2023] Open
Abstract
DNA double-strand breaks (DSBs) have been recognized as the most serious lesions in irradiated cells. While several biochemical pathways capable of repairing these lesions have been identified, the mechanisms by which cells select a specific pathway for activation at a given DSB site remain poorly understood. Our knowledge of DSB induction and repair has increased dramatically since the discovery of ionizing radiation-induced foci (IRIFs), initiating the possibility of spatiotemporally monitoring the assembly and disassembly of repair complexes in single cells. IRIF exploration revealed that all post-irradiation processes-DSB formation, repair and misrepair-are strongly dependent on the characteristics of DSB damage and the microarchitecture of the whole affected chromatin domain in addition to the cell status. The microscale features of IRIFs, such as their morphology, mobility, spatiotemporal distribution, and persistence kinetics, have been linked to repair mechanisms. However, the influence of various biochemical and structural factors and their specific combinations on IRIF architecture remains unknown, as does the hierarchy of these factors in the decision-making process for a particular repair mechanism at each individual DSB site. New insights into the relationship between the physical properties of the incident radiation, chromatin architecture, IRIF architecture, and DSB repair mechanisms and repair efficiency are expected from recent developments in optical superresolution microscopy (nanoscopy) techniques that have shifted our ability to analyze chromatin and IRIF architectures towards the nanoscale. In the present review, we discuss this relationship, attempt to correlate still rather isolated nanoscale studies with already better-understood aspects of DSB repair at the microscale, and consider whether newly emerging "correlated multiscale structuromics" can revolutionarily enhance our knowledge in this field.
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Affiliation(s)
- Martin Falk
- Institute of Biophysics, The Czech Academy of Sciences, 612 65 Brno, Czech Republic
| | - Michael Hausmann
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany;
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Alhendi ASN, Royle NJ. The absence of (TCAGGG) n repeats in some telomeres, combined with variable responses to NR2F2 depletion, suggest that this nuclear receptor plays an indirect role in the alternative lengthening of telomeres. Sci Rep 2020; 10:20597. [PMID: 33244044 PMCID: PMC7691514 DOI: 10.1038/s41598-020-77606-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 11/04/2020] [Indexed: 12/26/2022] Open
Abstract
The alternative lengthening of telomeres (ALT) facilitates telomere lengthening by a DNA strand invasion and copying mechanism. The nuclear receptors (NRs), NR2F2 and NR2C2, can bind to (TCAGGG)n variant repeats within telomeres and it has been proposed that this facilitates telomere interactions in ALT+ cells. Here we show that the frequency of cells with detectable NR2F2 and NR2C2 nuclear foci varies considerably between ALT+ cell lines and does not correlate with the level of protein expression. In addition, four of five ALT+ cell lines lack (TCAGGG)n repeats in some telomeres, indicating that direct NR binding does not play a role in ALT at these telomeres. NR2F2-depletion altered the abundance of C-circles and APBs but the direction of the response was inconsistent between three ALT+ cell lines. Moreover, transcriptome analysis following NR2F2-depletion in the ALT+ cell lines revealed different very responses. For example, NR2F2-depletion down-regulated many genes in U2OS cells, consistent with the cell cycle arrest and changes to ALT markers, but these features were not shared by the other two ALT+ cell lines. Among 86 ALT-associated genes, only MND1 showed consistent down-regulation across three NR2F2-depleted ALT+ cell lines. Altogether our data suggest that NR2F2 does not play a direct role in ALT and we speculate about an alternative role for this NR in a DNA damage response at telomeres.
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Affiliation(s)
- Ahmed S N Alhendi
- Department of Genetics and Genome Biology, University of Leicester, Leicester, LE1 3HE, UK
| | - Nicola J Royle
- Department of Genetics and Genome Biology, University of Leicester, Leicester, LE1 3HE, UK.
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37
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Rother MB, Pellegrino S, Smith R, Gatti M, Meisenberg C, Wiegant WW, Luijsterburg MS, Imhof R, Downs JA, Vertegaal ACO, Huet S, Altmeyer M, van Attikum H. CHD7 and 53BP1 regulate distinct pathways for the re-ligation of DNA double-strand breaks. Nat Commun 2020; 11:5775. [PMID: 33188175 PMCID: PMC7666215 DOI: 10.1038/s41467-020-19502-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 10/15/2020] [Indexed: 01/16/2023] Open
Abstract
Chromatin structure is dynamically reorganized at multiple levels in response to DNA double-strand breaks (DSBs). Yet, how the different steps of chromatin reorganization are coordinated in space and time to differentially regulate DNA repair pathways is insufficiently understood. Here, we identify the Chromodomain Helicase DNA Binding Protein 7 (CHD7), which is frequently mutated in CHARGE syndrome, as an integral component of the non-homologous end-joining (NHEJ) DSB repair pathway. Upon recruitment via PARP1-triggered chromatin remodeling, CHD7 stimulates further chromatin relaxation around DNA break sites and brings in HDAC1/2 for localized chromatin de-acetylation. This counteracts the CHD7-induced chromatin expansion, thereby ensuring temporally and spatially controlled 'chromatin breathing' upon DNA damage, which we demonstrate fosters efficient and accurate DSB repair by controlling Ku and LIG4/XRCC4 activities. Loss of CHD7-HDAC1/2-dependent cNHEJ reinforces 53BP1 assembly at the damaged chromatin and shifts DSB repair to mutagenic NHEJ, revealing a backup function of 53BP1 when cNHEJ fails.
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Grants
- 25715 Cancer Research UK
- 714326 European Research Council
- MR/N02155X/2 Medical Research Council
- MR/N02155X/1 Medical Research Council
- This research was financially supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (ERC-StG 714326 to M.A.; ERC-StG 310913 to A.C.O.V.; ERC-CoG 50364 to H.v.A), the Swiss National Science Foundation (grants 150690 and 179057 to M.A.), grants from the Danish Research Council (DFF 1333-00037B and 1331-00732B to M.A.), NWO-VENI (863.11.007) and NWO-VIDI (016.161.320) grants to M.S.L., People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/ 2007-2013) under REA grant agreement [(PCOFUND-GA-2013-609102), through the PRESTIGE program coordinated by Campus France (PRESTIGE-2017-2-0042), the Université Bretagne-Loire and the Fondation ARC pour la recherche sur le cancer (PDF20181208405) to R.S., the Ligue contre le Cancer du Grand-Ouest (committees 22 and 35), the Fondation ARC pour la recherche sur le cancer (20161204883), the Agence Nationale de la Recherche (PRC-2018 REPAIRCHROM) and the Institut Universitaire de France to S.H., and the Medical Research Council (MR/N02155X/1) to C.M. and J.A.D..
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Affiliation(s)
- Magdalena B Rother
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Stefania Pellegrino
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland
| | - Rebecca Smith
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes)-UMR 6290, BIOSIT-UMS3480, F-35000, Rennes, France
| | - Marco Gatti
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland
| | | | - Wouter W Wiegant
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Ralph Imhof
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland
| | - Jessica A Downs
- The Institute of Cancer Research, Royal Cancer Hospital, London, UK
| | - Alfred C O Vertegaal
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Sébastien Huet
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes)-UMR 6290, BIOSIT-UMS3480, F-35000, Rennes, France
- Institut Universitaire de France, Paris, France
| | - Matthias Altmeyer
- Department of Molecular Mechanisms of Disease, University of Zurich, Zurich, Switzerland.
| | - Haico van Attikum
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
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Double strand break (DSB) repair in Cyanobacteria: Understanding the process in an ancient organism. DNA Repair (Amst) 2020; 95:102942. [DOI: 10.1016/j.dnarep.2020.102942] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/19/2020] [Accepted: 07/26/2020] [Indexed: 02/07/2023]
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Timpano S, Picketts DJ. Neurodevelopmental Disorders Caused by Defective Chromatin Remodeling: Phenotypic Complexity Is Highlighted by a Review of ATRX Function. Front Genet 2020; 11:885. [PMID: 32849845 PMCID: PMC7432156 DOI: 10.3389/fgene.2020.00885] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 07/20/2020] [Indexed: 12/15/2022] Open
Abstract
The ability to determine the genetic etiology of intellectual disability (ID) and neurodevelopmental disorders (NDD) has improved immensely over the last decade. One prevailing metric from these studies is the large percentage of genes encoding epigenetic regulators, including many members of the ATP-dependent chromatin remodeling enzyme family. Chromatin remodeling proteins can be subdivided into five classes that include SWI/SNF, ISWI, CHD, INO80, and ATRX. These proteins utilize the energy from ATP hydrolysis to alter nucleosome positioning and are implicated in many cellular processes. As such, defining their precise roles and contributions to brain development and disease pathogenesis has proven to be complex. In this review, we illustrate that complexity by reviewing the roles of ATRX on genome stability, replication, and transcriptional regulation and how these mechanisms provide key insight into the phenotype of ATR-X patients.
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Affiliation(s)
- Sara Timpano
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - David J. Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Department of Medicine, University of Ottawa, Ottawa, ON, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada
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40
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Strand with mutagenic lesion is preferentially used as a template in the region of a bi-stranded clustered DNA damage site in Escherichia coli. Sci Rep 2020; 10:9737. [PMID: 32546758 PMCID: PMC7297740 DOI: 10.1038/s41598-020-66651-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/20/2020] [Indexed: 11/08/2022] Open
Abstract
The damaging potential of ionizing radiation arises largely from the generation of clustered DNA damage sites within cells. Previous studies using synthetic DNA lesions have demonstrated that models of clustered DNA damage exhibit enhanced mutagenic potential of the comprising lesions. However, little is known regarding the processes that lead to mutations in these sites, apart from the fact that base excision repair of lesions within the cluster is compromised. Unique features of the mutation frequencies within bi-stranded clusters have led researchers to speculate that the strand containing the mutagenic lesion is preferentially used as the template for DNA synthesis. To gain further insights into the processing of clustered DNA damage sites, we used a plasmid-based assay in E. coli cells. Our findings revealed that the strand containing a mutagenic lesion within a bi-stranded clustered DNA damage site is frequently used as the template. This suggests the presence of an, as yet unknown, strand synthesis process that is unrelated to base excision repair, and that this process plays an important role in mutagenesis. The length of the region of strand preference was found to be determined by DNA polymerase I.
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41
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Interaction of Deubiquitinase 2A-DUB/MYSM1 with DNA Repair and Replication Factors. Int J Mol Sci 2020; 21:ijms21113762. [PMID: 32466590 PMCID: PMC7312997 DOI: 10.3390/ijms21113762] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 05/07/2020] [Accepted: 05/19/2020] [Indexed: 01/09/2023] Open
Abstract
The deubiquitination of histone H2A on lysine 119 by 2A-DUB/MYSM1, BAP1, USP16, and other enzymes is required for key cellular processes, including transcriptional activation, apoptosis, and cell cycle control, during normal hematopoiesis and tissue development, and in tumor cells. Based on our finding that MYSM1 colocalizes with γH2AX foci in human peripheral blood mononuclear cells, leukemia cells, and melanoma cells upon induction of DNA double-strand breaks with topoisomerase inhibitor etoposide, we applied a mass spectrometry-based proteomics approach to identify novel 2A-DUB/MYSM1 interaction partners in DNA-damage responses. Differential display of MYSM1 binding proteins significantly enriched after exposure of 293T cells to etoposide revealed an interacting network of proteins involved in DNA damage and replication, including factors associated with poor melanoma outcome. In the context of increased DNA-damage in a variety of cell types in Mysm1-deficient mice, in bone marrow cells upon aging and in UV-exposed Mysm1-deficient skin, our current mass spectrometry data provide additional evidence for an interaction between MYSM1 and key DNA replication and repair factors, and indicate a potential function of 2A-DUB/MYSM1 in DNA repair processes.
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Tarsounas M, Sung P. The antitumorigenic roles of BRCA1-BARD1 in DNA repair and replication. Nat Rev Mol Cell Biol 2020; 21:284-299. [PMID: 32094664 PMCID: PMC7204409 DOI: 10.1038/s41580-020-0218-z] [Citation(s) in RCA: 187] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2020] [Indexed: 11/09/2022]
Abstract
The tumour suppressor breast cancer type 1 susceptibility protein (BRCA1) promotes DNA double-strand break (DSB) repair by homologous recombination and protects DNA replication forks from attrition. BRCA1 partners with BRCA1-associated RING domain protein 1 (BARD1) and other tumour suppressor proteins to mediate the initial nucleolytic resection of DNA lesions and the recruitment and regulation of the recombinase RAD51. The discovery of the opposing functions of BRCA1 and the p53-binding protein 1 (53BP1)-associated complex in DNA resection sheds light on how BRCA1 influences the choice of homologous recombination over non-homologous end joining and potentially other mutagenic pathways of DSB repair. Understanding the functional crosstalk between BRCA1-BARD1 and its cofactors and antagonists will illuminate the molecular basis of cancers that arise from a deficiency or misregulation of chromosome damage repair and replication fork maintenance. Such knowledge will also be valuable for understanding acquired tumour resistance to poly(ADP-ribose) polymerase (PARP) inhibitors and other therapeutics and for the development of new treatments. In this Review, we discuss recent advances in elucidating the mechanisms by which BRCA1-BARD1 functions in DNA repair, replication fork maintenance and tumour suppression, and its therapeutic relevance.
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Affiliation(s)
- Madalena Tarsounas
- Genome Stability and Tumourigenesis Group, Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK.
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA.
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43
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Nath S, Nagaraju G. FANCJ helicase promotes DNA end resection by facilitating CtIP recruitment to DNA double-strand breaks. PLoS Genet 2020; 16:e1008701. [PMID: 32251466 PMCID: PMC7162537 DOI: 10.1371/journal.pgen.1008701] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 04/16/2020] [Accepted: 02/28/2020] [Indexed: 12/13/2022] Open
Abstract
FANCJ helicase mutations are known to cause hereditary breast and ovarian cancers as well as bone marrow failure syndrome Fanconi anemia. FANCJ plays an important role in the repair of DNA inter-strand crosslinks and DNA double-strand breaks (DSBs) by homologous recombination (HR). Nonetheless, the molecular mechanism by which FANCJ controls HR mediated DSB repair is obscure. Here, we show that FANCJ promotes DNA end resection by recruiting CtIP to the sites of DSBs. This recruitment of CtIP is dependent on FANCJ K1249 acetylation. Notably, FANCJ acetylation is dependent on FANCJ S990 phosphorylation by CDK. The CDK mediated phosphorylation of FANCJ independently facilitates its interaction with BRCA1 at damaged DNA sites and promotes DNA end resection by CtIP recruitment. Strikingly, mutational studies reveal that ATP binding competent but hydrolysis deficient FANCJ partially supports end resection, indicating that in addition to the scaffolding role of FANCJ in CtIP recruitment, its helicase activity is important for promoting end resection. Together, these data unravel a novel function of FANCJ helicase in DNA end resection and provide mechanistic insights into its role in repairing DSBs by HR and in genome maintenance. Homologous recombination has been considered as an error-free pathway in repairing DSBs and maintaining genome stability. Cyclin-dependent kinases (CDKs) and various factors including MRE11, CtIP, EXO1, and BLM helicase participate in DNA end resection to promote HR mediated DSB repair. Despite the identification of FANCJ helicase role in HR and tumor suppression, the molecular mechanism by which FANCJ helicase participates in HR is obscure. Here, we show that FANCJ helicase controls DNA end resection by recruiting CtIP to the sites of DSBs. The loading of CtIP is dependent on FANCJ acetylation which is mediated by CDK dependent phosphorylation of FANCJ. Moreover, in addition to FANCJ mediated CtIP recruitment, its helicase activity is also essential for DNA end resection. Our data identify FANCJ as a novel player in the DNA end resection and provide insights into its role in HR mediated DSB repair.
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Affiliation(s)
- Sarmi Nath
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Ganesh Nagaraju
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
- * E-mail:
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44
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Kim C, Sung S, Kim J, Lee J. Repair and Reconstruction of Telomeric and Subtelomeric Regions and Genesis of New Telomeres: Implications for Chromosome Evolution. Bioessays 2020; 42:e1900177. [PMID: 32236965 DOI: 10.1002/bies.201900177] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 02/20/2020] [Indexed: 12/12/2022]
Abstract
DNA damage repair within telomeres are suppressed to maintain the integrity of linear chromosomes, but the accidental activation of repairs can lead to genome instability. This review develops the concept that mechanisms to repair DNA damage in telomeres contribute to genetic variability and karyotype evolution, rather than catastrophe. Spontaneous breaks in telomeres can be repaired by telomerase, but in some cases DNA repair pathways are activated, and can cause chromosomal rearrangements or fusions. The resultant changes can also affect subtelomeric regions that are adjacent to telomeres. Subtelomeres are actively involved in such chromosomal changes, and are therefore the most variable regions in the genome. The case of Caenorhabditis elegans in the context of changes of subtelomeric structures revealed by long-read sequencing is also discussed. Theoretical and methodological issues covered in this review will help to explore the mechanism of chromosome evolution by reconstruction of chromosomal ends in nature.
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Affiliation(s)
- Chuna Kim
- Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08827, Korea.,Aging Research Institute, Korea Research Institute of Bioscience and Biotechnology, Gwahak-ro 125, Daejeon, 34141, Korea
| | - Sanghyun Sung
- Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08827, Korea
| | - Jun Kim
- Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08827, Korea
| | - Junho Lee
- Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08827, Korea
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45
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Tang S, Li Z, Yang L, Shen L, Wang Y. A potential new role of ATM inhibitor in radiotherapy: suppressing ionizing Radiation-Activated EGFR. Int J Radiat Biol 2020; 96:461-468. [PMID: 31859574 PMCID: PMC7500639 DOI: 10.1080/09553002.2020.1707325] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 10/10/2019] [Accepted: 12/14/2019] [Indexed: 12/31/2022]
Abstract
Purpose: Although EGFR inhibitor (EGFRi) is used in cancer therapy to suppress tumor growth and resistance to treatment including radiotherapy, EGFRi resistance frequently developed, which significantly reduced treatment outcomes. Therefore, developing alternative approaches for EGFRi is of great importance. Based on our recent observation that ATM inhibitor (ATMi) efficiently inhibited ionizing radiation (IR)-induced EGFR activation in mouse embryo fibroblasts (MEF), the main purpose of this study is to determine whether ATMi could inhibit IR-induced EGFR activation in human tumor cell lines and explore its potential in EGFRi-alternative therapies.Materials and methods: We compared the effects of ATMi, EGFRi individually or in combination on IR-induced EGFR phosphorylation, cell growth and radio-sensitization in nine human tumor cell lines including lung adenocarcinoma (A549 and H358), glioblastoma (LN229), cervical cancer (HeLa), colorectal carcinoma (SW480 and HCT116) and nasopharygeal carcinoma (5-8 F, 6-10B and HK1) cell lines. In addition, we detected the effects of ATMi, EGFRi alone or both on the efficiency of non-homologous end-joining (NHEJ) and homologous recombination (HR) using I-SceI -GFP based NHEJ or HR reporter cell lines.Results: Compared to EGFRi treatment, ATMi treatment decreased IR-induced EGFR phosphorylation, suppressed growth and increased IR sensitization in tested cell lines at a similar or even more efficient level. Combining ATMi and EGFRi did not significantly increased the effects on these phenotypes as ATMi treatment alone. Also, similar to ATMi, EGFRi mainly reduced the efficiency of HR but not NHEJ although combining ATMi and EGFRi further inhibited the HR efficiency.Conclusions: Our study demonstrates that ATMi can function like EGFRi in human tumor cells to inhibit tumor cell growth and sensitize the tumor cells to IR, suggesting that ATMi treatment as an alternative approach may exert anticancer effects on EGFRi-resistant tumor cells and facilitate radiotherapy.
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Affiliation(s)
- Siyuan Tang
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, China
| | - Zhentian Li
- Department of Radiation Oncology, Emory University School of Medicine, Winship Cancer Institute of Emory University, Atlanta, GA, United States
| | - Lifang Yang
- Cancer Research Institute, School of Basic Medicine Science, Central South University, Changsha, China
| | - Liangfang Shen
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, China
| | - Ya Wang
- Department of Radiation Oncology, Emory University School of Medicine, Winship Cancer Institute of Emory University, Atlanta, GA, United States
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Smirnov A, Fishman V, Yunusova A, Korablev A, Serova I, Skryabin BV, Rozhdestvensky TS, Battulin N. DNA barcoding reveals that injected transgenes are predominantly processed by homologous recombination in mouse zygote. Nucleic Acids Res 2020; 48:719-735. [PMID: 31740957 PMCID: PMC7145541 DOI: 10.1093/nar/gkz1085] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/29/2019] [Accepted: 11/05/2019] [Indexed: 12/14/2022] Open
Abstract
Mechanisms that ensure repair of double-strand DNA breaks (DSBs) are instrumental in the integration of foreign DNA into the genome of transgenic organisms. After pronuclear microinjection, exogenous DNA is usually found as a concatemer comprising multiple co-integrated transgene copies. Here, we investigated the contribution of various DSB repair pathways to the concatemer formation. We injected mouse zygotes with a pool of linear DNA molecules carrying unique barcodes at both ends and obtained 10 transgenic embryos with 1–300 transgene copies. Sequencing the barcodes allowed us to assign relative positions to the copies in concatemers and detect recombination events that occurred during integration. Cumulative analysis of approximately 1,000 integrated copies reveals that over 80% of them underwent recombination when their linear ends were processed by synthesis-dependent strand annealing (SDSA) or double-strand break repair (DSBR). We also observed evidence of double Holliday junction (dHJ) formation and crossing over during the concatemer formations. Sequencing indels at the junctions between copies shows that at least 10% of DNA molecules introduced into the zygotes are ligated by non-homologous end joining (NHEJ). Our barcoding approach, verified with Pacific Biosciences Single Molecule Real-Time (SMRT) long-range sequencing, documents high activity of homologous recombination after DNA microinjection.
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Affiliation(s)
| | - Veniamin Fishman
- Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia.,Novosibirsk State University, Novosibirsk, Russia
| | | | - Alexey Korablev
- Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia
| | - Irina Serova
- Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia
| | - Boris V Skryabin
- Medical Faculty, Core Facility Transgenic animal and genetic engineering Models (TRAM), University of Muenster, Muenster, Germany
| | - Timofey S Rozhdestvensky
- Medical Faculty, Core Facility Transgenic animal and genetic engineering Models (TRAM), University of Muenster, Muenster, Germany
| | - Nariman Battulin
- Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia.,Novosibirsk State University, Novosibirsk, Russia
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47
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Cicconi A, Chang S. Shelterin and the replisome: at the intersection of telomere repair and replication. Curr Opin Genet Dev 2020; 60:77-84. [PMID: 32171974 DOI: 10.1016/j.gde.2020.02.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 02/10/2020] [Accepted: 02/12/2020] [Indexed: 12/30/2022]
Abstract
Telomeres are G-rich repetitive sequences that are difficult to replicate, resulting in increased replication stress that can threaten genome stability. Shelterin protects telomeres from engaging in aberrant DNA repair and dictates the choice of DNA repair pathway at dysfunctional telomeres. Recently, shelterin has been shown to participate in telomere replication. Here we review the most recent discoveries documenting the mechanisms by which shelterin represses DNA repair pathways at telomeres while assisting its replication. The interplay between shelterin and the replisome complex highlights a novel connection between telomere maintenance and repair.
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Affiliation(s)
- Alessandro Cicconi
- Department of Laboratory Medicine, Yale University School of Medicine, 330 Cedar St., New Haven, CT 06520, USA
| | - Sandy Chang
- Department of Laboratory Medicine, Yale University School of Medicine, 330 Cedar St., New Haven, CT 06520, USA; Department of Pathology, Yale University School of Medicine, 330 Cedar St., New Haven, CT 06520, USA; Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, 330 Cedar St., New Haven, CT 06520, USA.
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48
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RAD52: Viral Friend or Foe? Cancers (Basel) 2020; 12:cancers12020399. [PMID: 32046320 PMCID: PMC7072633 DOI: 10.3390/cancers12020399] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/06/2020] [Accepted: 02/06/2020] [Indexed: 02/06/2023] Open
Abstract
Mammalian Radiation Sensitive 52 (RAD52) is a gene whose scientific reputation has recently seen a strong resurgence. In the past decade, RAD52, which was thought to be dispensable for most DNA repair and recombination reactions in mammals, has been shown to be important for a bevy of DNA metabolic pathways. One of these processes is termed break-induced replication (BIR), a mechanism that can be used to re-start broken replication forks and to elongate the ends of chromosomes in telomerase-negative cells. Viruses have historically evolved a myriad of mechanisms in which they either conscript cellular factors or, more frequently, inactivate them as a means to enable their own replication and survival. Recent data suggests that Adeno-Associated Virus (AAV) may replicate its DNA in a BIR-like fashion and/or utilize RAD52 to facilitate viral transduction and, as such, likely conscripts/requires the host RAD52 protein to promote its perpetuation.
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49
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TIRR: a potential front runner in HDR race−hypotheses and perspectives. Mol Biol Rep 2020; 47:2371-2379. [DOI: 10.1007/s11033-020-05285-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 01/27/2020] [Indexed: 01/01/2023]
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50
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Epum EA, Mohan MJ, Ruppe NP, Friedman KL. Interaction of yeast Rad51 and Rad52 relieves Rad52-mediated inhibition of de novo telomere addition. PLoS Genet 2020; 16:e1008608. [PMID: 32012161 PMCID: PMC7018233 DOI: 10.1371/journal.pgen.1008608] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 02/13/2020] [Accepted: 01/13/2020] [Indexed: 12/26/2022] Open
Abstract
DNA double-strand breaks (DSBs) are toxic forms of DNA damage that must be repaired to maintain genome integrity. Telomerase can act upon a DSB to create a de novo telomere, a process that interferes with normal repair and creates terminal deletions. We previously identified sequences in Saccharomyces cerevisiae (SiRTAs; Sites of Repair-associated Telomere Addition) that undergo unusually high frequencies of de novo telomere addition, even when the original chromosome break is several kilobases distal to the eventual site of telomerase action. Association of the single-stranded telomere binding protein Cdc13 with a SiRTA is required to stimulate de novo telomere addition. Because extensive resection must occur prior to Cdc13 binding, we utilized these sites to monitor the effect of proteins involved in homologous recombination. We find that telomere addition is significantly reduced in the absence of the Rad51 recombinase, while loss of Rad52, required for Rad51 nucleoprotein filament formation, has no effect. Deletion of RAD52 suppresses the defect of the rad51Δ strain, suggesting that Rad52 inhibits de novo telomere addition in the absence of Rad51. The ability of Rad51 to counteract this effect of Rad52 does not require DNA binding by Rad51, but does require interaction between the two proteins, while the inhibitory effect of Rad52 depends on its interaction with Replication Protein A (RPA). Intriguingly, the genetic interactions we report between RAD51 and RAD52 are similar to those previously observed in the context of checkpoint adaptation. Forced recruitment of Cdc13 fully restores telomere addition in the absence of Rad51, suggesting that Rad52, through its interaction with RPA-coated single-stranded DNA, inhibits the ability of Cdc13 to bind and stimulate telomere addition. Loss of the Rad51-Rad52 interaction also stimulates a subset of Rad52-dependent microhomology-mediated repair (MHMR) events, consistent with the known ability of Rad51 to prevent single-strand annealing. DNA double-strand breaks (DSBs) can lead to chromosome loss and rearrangement associated with cancer and genetic disease, so understanding how the cell coordinates multiple possible repair pathways is of critical importance. Telomerase is a ribonucleoprotein enzyme that uses an intrinsic RNA component as a template for the addition of highly repetitive, protective sequences (called telomeres) at normal chromosome ends. Rarely, telomerase acts upon a DSB to create a new or de novo telomere with resultant loss of sequences distal to the site of telomere addition. Here, we show that interactions between proteins with known roles during DSB repair modulate the probability of telomerase action at hotspots of de novo telomere addition in the yeast genome by influencing the association of Cdc13, a protein required for telomerase recruitment, with sites of telomere addition. Intriguingly, the same interactions that facilitate telomere addition prevent other types of rearrangements in response to chromosome breaks.
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Affiliation(s)
- Esther A. Epum
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Michael J. Mohan
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Nicholas P. Ruppe
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Katherine L. Friedman
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- * E-mail:
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