1
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Inagaki Y, Hashimoto K, Wakamori S, Katsuta R, Yajima A, Kaida D, Ishigami K. Synthesis, growth inhibitory activity against tumor cells, and structure-activity relationship of CGK733 and its analogs. Biosci Biotechnol Biochem 2024; 88:747-758. [PMID: 38678003 DOI: 10.1093/bbb/zbae047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 04/11/2024] [Indexed: 04/29/2024]
Abstract
CGK733 was reported as a compound that inhibited ATM/ATR kinase activities and blocked their checkpoint signaling pathways with great selectivity. However, this paper was subsequently retracted, and the truth about the activity of CGK733 remains unclear. We synthesized various analogs of CGK733 with a modification of the carboxylic acid moiety and/or the aniline derivative moiety to accumulate knowledge of the structure-activity relationship of this compound. Growth inhibitory activity of CGK733 and novel 35 analogs against HeLa S3 cells was evaluated, and the structure-activity relationship revealed that analogs with the 2-naphthyl or 4-fluorophenyl group instead of the benzhydryl group have activity comparable to CGK733 and that the 3-nitro group on the aniline moiety significantly affects the activity.
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Affiliation(s)
- Yuta Inagaki
- Department of Chemistry for Life Sciences and Agriculture, Tokyo University of Agriculture, Tokyo, Japan
| | - Kohki Hashimoto
- Department of Chemistry for Life Sciences and Agriculture, Tokyo University of Agriculture, Tokyo, Japan
| | - Shinnosuke Wakamori
- Department of Chemistry for Life Sciences and Agriculture, Tokyo University of Agriculture, Tokyo, Japan
| | - Ryo Katsuta
- Department of Chemistry for Life Sciences and Agriculture, Tokyo University of Agriculture, Tokyo, Japan
| | - Arata Yajima
- Department of Chemistry for Life Sciences and Agriculture, Tokyo University of Agriculture, Tokyo, Japan
| | - Daisuke Kaida
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Ken Ishigami
- Department of Chemistry for Life Sciences and Agriculture, Tokyo University of Agriculture, Tokyo, Japan
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2
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Vipat S, Moiseeva TN. The TIMELESS Roles in Genome Stability and Beyond. J Mol Biol 2024; 436:168206. [PMID: 37481157 DOI: 10.1016/j.jmb.2023.168206] [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: 05/01/2023] [Revised: 06/20/2023] [Accepted: 07/12/2023] [Indexed: 07/24/2023]
Abstract
TIMELESS protein (TIM) protects replication forks from stalling at difficult-to-replicate regions and plays an important role in DNA damage response, including checkpoint signaling, protection of stalled replication forks and DNA repair. Loss of TIM causes severe replication stress, while its overexpression is common in various types of cancer, providing protection from DNA damage and resistance to chemotherapy. Although TIM has mostly been studied for its part in replication stress response, its additional roles in supporting genome stability and a wide variety of other cellular pathways are gradually coming to light. This review discusses the diverse functions of TIM and its orthologs in healthy and cancer cells, open questions, and potential future directions.
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Affiliation(s)
- Sameera Vipat
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn 12618, Estonia
| | - Tatiana N Moiseeva
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn 12618, Estonia.
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3
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Venkadakrishnan J, Lahane G, Dhar A, Xiao W, Bhat KM, Pandita TK, Bhat A. Implications of Translesion DNA Synthesis Polymerases on Genomic Stability and Human Health. Mol Cell Biol 2023; 43:401-425. [PMID: 37439479 PMCID: PMC10448981 DOI: 10.1080/10985549.2023.2224199] [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: 01/31/2023] [Revised: 05/03/2023] [Accepted: 06/01/2023] [Indexed: 07/14/2023] Open
Abstract
Replication fork arrest-induced DNA double strand breaks (DSBs) caused by lesions are effectively suppressed in cells due to the presence of a specialized mechanism, commonly referred to as DNA damage tolerance (DDT). In eukaryotic cells, DDT is facilitated through translesion DNA synthesis (TLS) carried out by a set of DNA polymerases known as TLS polymerases. Another parallel mechanism, referred to as homology-directed DDT, is error-free and involves either template switching or fork reversal. The significance of the DDT pathway is well established. Several diseases have been attributed to defects in the TLS pathway, caused either by mutations in the TLS polymerase genes or dysregulation. In the event of a replication fork encountering a DNA lesion, cells switch from high-fidelity replicative polymerases to low-fidelity TLS polymerases, which are associated with genomic instability linked with several human diseases including, cancer. The role of TLS polymerases in chemoresistance has been recognized in recent years. In addition to their roles in the DDT pathway, understanding noncanonical functions of TLS polymerases is also a key to unraveling their importance in maintaining genomic stability. Here we summarize the current understanding of TLS pathway in DDT and its implication for human health.
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Affiliation(s)
| | - Ganesh Lahane
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad Campus, Hyderabad, India
| | - Arti Dhar
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad Campus, Hyderabad, India
| | - Wei Xiao
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada
| | - Krishna Moorthi Bhat
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, USA
| | - Tej K. Pandita
- Center for Genomics and Precision Medicine, Texas A&M College of Medicine, Houston, Texas, USA
| | - Audesh Bhat
- Center for Molecular Biology, Central University of Jammu, UT Jammu and Kashmir, India
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4
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Shen J, Wang Q, Mao Y, Gao W, Duan S. Targeting the p53 signaling pathway in cancers: Molecular mechanisms and clinical studies. MedComm (Beijing) 2023; 4:e288. [PMID: 37256211 PMCID: PMC10225743 DOI: 10.1002/mco2.288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 04/25/2023] [Accepted: 05/08/2023] [Indexed: 06/01/2023] Open
Abstract
Tumor suppressor p53 can transcriptionally activate downstream genes in response to stress, and then regulate the cell cycle, DNA repair, metabolism, angiogenesis, apoptosis, and other biological responses. p53 has seven functional domains and 12 splice isoforms, and different domains and subtypes play different roles. The activation and inactivation of p53 are finely regulated and are associated with phosphorylation/acetylation modification and ubiquitination modification, respectively. Abnormal activation of p53 is closely related to the occurrence and development of cancer. While targeted therapy of the p53 signaling pathway is still in its early stages and only a few drugs or treatments have entered clinical trials, the development of new drugs and ongoing clinical trials are expected to lead to the widespread use of p53 signaling-targeted therapy in cancer treatment in the future. TRIAP1 is a novel p53 downstream inhibitor of apoptosis. TRIAP1 is the homolog of yeast mitochondrial intermembrane protein MDM35, which can play a tumor-promoting role by blocking the mitochondria-dependent apoptosis pathway. This work provides a systematic overview of recent basic research and clinical progress in the p53 signaling pathway and proposes that TRIAP1 is an important therapeutic target downstream of p53 signaling.
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Affiliation(s)
- Jinze Shen
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang ProvinceSchool of MedicineHangzhou City UniversityHangzhouZhejiangChina
| | - Qurui Wang
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang ProvinceSchool of MedicineHangzhou City UniversityHangzhouZhejiangChina
| | - Yunan Mao
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang ProvinceSchool of MedicineHangzhou City UniversityHangzhouZhejiangChina
| | - Wei Gao
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang ProvinceSchool of MedicineHangzhou City UniversityHangzhouZhejiangChina
| | - Shiwei Duan
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang ProvinceSchool of MedicineHangzhou City UniversityHangzhouZhejiangChina
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5
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Manolakou T, Nikolopoulos D, Gkikas D, Filia A, Samiotaki M, Stamatakis G, Fanouriakis A, Politis P, Banos A, Alissafi T, Verginis P, Boumpas DT. ATR-mediated DNA damage responses underlie aberrant B cell activity in systemic lupus erythematosus. SCIENCE ADVANCES 2022; 8:eabo5840. [PMID: 36306362 PMCID: PMC9616496 DOI: 10.1126/sciadv.abo5840] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
B cells orchestrate autoimmune responses in patients with systemic lupus erythematosus (SLE), but broad-based B cell-directed therapies show only modest efficacy while blunting humoral immune responses to vaccines and inducing immunosuppression. Development of more effective therapies targeting pathogenic clones is a currently unmet need. Here, we demonstrate enhanced activation of the ATR/Chk1 pathway of the DNA damage response (DDR) in B cells of patients with active SLE disease. Treatment of B cells with type I IFN, a key driver of immunity in SLE, induced expression of ATR via binding of interferon regulatory factor 1 to its gene promoter. Pharmacologic targeting of ATR in B cells, via a specific inhibitor (VE-822), attenuated their immunogenic profile, including proinflammatory cytokine secretion, plasmablast formation, and antibody production. Together, these findings identify the ATR-mediated DDR axis as the orchestrator of the type I IFN-mediated B cell responses in SLE and as a potential novel therapeutic target.
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Affiliation(s)
- Theodora Manolakou
- Center for Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, 115 27 Athens, Greece
- School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
- Corresponding author. (T.M.); (P.V.); (D.T.B.)
| | - Dionysis Nikolopoulos
- Center for Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, 115 27 Athens, Greece
- School of Medicine, National and Kapodistrian University of Athens, 115 27 Athens, Greece
| | - Dimitrios Gkikas
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens, 115 27, Athens, Greece
| | - Anastasia Filia
- Center for Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, 115 27 Athens, Greece
| | - Martina Samiotaki
- Institute for Bioinnovation, Biomedical Sciences Research Center Alexander Fleming, Vari, Attica, Greece
- Centre of New Biotechnologies and Precision Medicine (CNBPM) School of Medicine, National and Kapodistrian University of Athens, Athens 115 27, Greece
| | - George Stamatakis
- Institute for Bioinnovation, Biomedical Sciences Research Center Alexander Fleming, Vari, Attica, Greece
- Centre of New Biotechnologies and Precision Medicine (CNBPM) School of Medicine, National and Kapodistrian University of Athens, Athens 115 27, Greece
| | | | - Panagiotis Politis
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens, 115 27, Athens, Greece
- School of Medicine, European University Cyprus, 1516, Nicosia, Cyprus
| | - Aggelos Banos
- Center for Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, 115 27 Athens, Greece
| | - Themis Alissafi
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens, 115 27, Athens, Greece
- Laboratory of Biology, National and Kapodistrian University of Athens Medical School, 124 62 Athens, Greece
| | - Panayotis Verginis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, 700 13 Heraklion, Greece
- Laboratory of Immune Regulation and Tolerance, Division of Basic Sciences, University of Crete Medical School, 700 13 Heraklion, Greece
- Corresponding author. (T.M.); (P.V.); (D.T.B.)
| | - Dimitrios T. Boumpas
- Center for Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, 115 27 Athens, Greece
- Joint Rheumatology Program, 4th Department of Internal Medicine, Attikon University Hospital, National and Kapodistrian University of Athens Medical School, 124 62 Athens, Greece
- Corresponding author. (T.M.); (P.V.); (D.T.B.)
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6
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Ler AAL, Carty MP. DNA Damage Tolerance Pathways in Human Cells: A Potential Therapeutic Target. Front Oncol 2022; 11:822500. [PMID: 35198436 PMCID: PMC8859465 DOI: 10.3389/fonc.2021.822500] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 12/30/2021] [Indexed: 12/26/2022] Open
Abstract
DNA lesions arising from both exogenous and endogenous sources occur frequently in DNA. During DNA replication, the presence of unrepaired DNA damage in the template can arrest replication fork progression, leading to fork collapse, double-strand break formation, and to genome instability. To facilitate completion of replication and prevent the generation of strand breaks, DNA damage tolerance (DDT) pathways play a key role in allowing replication to proceed in the presence of lesions in the template. The two main DDT pathways are translesion synthesis (TLS), which involves the recruitment of specialized TLS polymerases to the site of replication arrest to bypass lesions, and homology-directed damage tolerance, which includes the template switching and fork reversal pathways. With some exceptions, lesion bypass by TLS polymerases is a source of mutagenesis, potentially contributing to the development of cancer. The capacity of TLS polymerases to bypass replication-blocking lesions induced by anti-cancer drugs such as cisplatin can also contribute to tumor chemoresistance. On the other hand, during homology-directed DDT the nascent sister strand is transiently utilised as a template for replication, allowing for error-free lesion bypass. Given the role of DNA damage tolerance pathways in replication, mutagenesis and chemoresistance, a more complete understanding of these pathways can provide avenues for therapeutic exploitation. A number of small molecule inhibitors of TLS polymerase activity have been identified that show synergy with conventional chemotherapeutic agents in killing cancer cells. In this review, we will summarize the major DDT pathways, explore the relationship between damage tolerance and carcinogenesis, and discuss the potential of targeting TLS polymerases as a therapeutic approach.
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Affiliation(s)
- Ashlynn Ai Li Ler
- Biochemistry, School of Biological and Chemical Sciences, The National University of Ireland (NUI) Galway, Galway, Ireland
| | - Michael P. Carty
- Biochemistry, School of Biological and Chemical Sciences, The National University of Ireland (NUI) Galway, Galway, Ireland
- DNA Damage Response Laboratory, Centre for Chromosome Biology, NUI Galway, Galway, Ireland
- *Correspondence: Michael P. Carty,
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7
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Pan Y, Yang Y, Huang R, Yang H, Huang Q, Ji Y, Dai J, Qiao K, Tang W, Xie L, Yin M, Ouyang J, Ning S, Su D. Ring finger protein 126 promotes breast cancer metastasis and serves as a potential target to improve the therapeutic sensitivity of ATR inhibitors. Breast Cancer Res 2022; 24:92. [PMID: 36539893 PMCID: PMC9764525 DOI: 10.1186/s13058-022-01586-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND/AIMS This study explores the relationship between the E3 ubiquitin ligase Ring finger protein 126 (RNF126) and early breast cancer metastasis and tests the hypothesis that RNF126 determines the efficacy of inhibitors targeting Ataxia telangiectasia mutated and Rad3-related kinase (ATR). METHODS Various metastasis-related genes were identified by univariable Cox proportional hazards regression analysis based on the GSE11121 dataset. The RNF126-related network modules were identified by WGCNA, whereas cell viability, invasion, and migration assays were performed to evaluate the biological characteristics of breast cancer cells with or without RNF126 knockdown. MTT, immunoblotting, immunofluorescence, and DNA fiber assays were conducted to determine the efficiency of ATR inhibitor in cells with or without RNF126 knockdown. RESULTS RNF126 was associated with early breast cancer metastasis. RNF126 promoted breast cancer cell proliferation, growth, migration, and invasion. ATR inhibitors were more effective at killing breast cancer cells with intact RNF126 due to replication stress compared with the corresponding cells with RNF126 knockdown. Cyclin-dependent kinase 2 (CDK2) was involved in regulating replication stress in breast cancer cells with intact RNF126. CONCLUSION A high level of expression of RNF126 in early breast cancer patients without lymph node metastases may indicate a high-risk type of metastatic disease, possibly due to RNF126, which may increase breast cancer cell proliferation and invasion. RNF126-expressing breast cancer cells exhibit CDK2-mediated replication stress that makes them potential targets for ATR inhibitors.
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Affiliation(s)
- You Pan
- grid.256607.00000 0004 1798 2653Department of Breast Surgery, Key Laboratory of Breast Cancer Diagnosis and Treatment Research of Guangxi Department of Education, Guangxi Medical University Cancer Hospital, Nanning, 530000 China
| | - Yuchao Yang
- grid.284723.80000 0000 8877 7471Guangdong Provincial Key Laboratory of Medical Biomechanics & Nation Key Discipline of Human Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510515 China
| | - Rong Huang
- grid.256607.00000 0004 1798 2653Department of Breast Surgery, Key Laboratory of Breast Cancer Diagnosis and Treatment Research of Guangxi Department of Education, Guangxi Medical University Cancer Hospital, Nanning, 530000 China
| | - Huawei Yang
- grid.256607.00000 0004 1798 2653Department of Breast Surgery, Key Laboratory of Breast Cancer Diagnosis and Treatment Research of Guangxi Department of Education, Guangxi Medical University Cancer Hospital, Nanning, 530000 China
| | - Qinghua Huang
- grid.256607.00000 0004 1798 2653Department of Breast Surgery, Key Laboratory of Breast Cancer Diagnosis and Treatment Research of Guangxi Department of Education, Guangxi Medical University Cancer Hospital, Nanning, 530000 China
| | - Yinan Ji
- grid.256607.00000 0004 1798 2653Department of Breast Surgery, Key Laboratory of Breast Cancer Diagnosis and Treatment Research of Guangxi Department of Education, Guangxi Medical University Cancer Hospital, Nanning, 530000 China
| | - Jingxing Dai
- grid.284723.80000 0000 8877 7471Guangdong Provincial Key Laboratory of Medical Biomechanics & Nation Key Discipline of Human Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510515 China
| | - Kun Qiao
- grid.412651.50000 0004 1808 3502Department of Breast Surgery, Harbin Medical University Cancer Hospital, Harbin, 150000 China
| | - Wei Tang
- grid.256607.00000 0004 1798 2653Department of Breast Surgery, Key Laboratory of Breast Cancer Diagnosis and Treatment Research of Guangxi Department of Education, Guangxi Medical University Cancer Hospital, Nanning, 530000 China
| | - Longgui Xie
- grid.256607.00000 0004 1798 2653Department of Breast Surgery, Key Laboratory of Breast Cancer Diagnosis and Treatment Research of Guangxi Department of Education, Guangxi Medical University Cancer Hospital, Nanning, 530000 China
| | - Ming Yin
- grid.284723.80000 0000 8877 7471Department of Imaging, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China
| | - Jun Ouyang
- grid.284723.80000 0000 8877 7471Guangdong Provincial Key Laboratory of Medical Biomechanics & Nation Key Discipline of Human Anatomy, School of Basic Medical Science, Southern Medical University, Guangzhou, 510515 China
| | - Shipeng Ning
- grid.256607.00000 0004 1798 2653Department of Breast Surgery, Key Laboratory of Breast Cancer Diagnosis and Treatment Research of Guangxi Department of Education, Guangxi Medical University Cancer Hospital, Nanning, 530000 China
| | - Danke Su
- grid.256607.00000 0004 1798 2653Department of Radiology, Guangxi Medical University Cancer Hospital, Nanning, 530000 China
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8
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Bello A, Jungnickel B. Impact of Chk1 dosage on somatic hypermutation in vivo. Immunol Cell Biol 2021; 99:879-893. [PMID: 34042197 DOI: 10.1111/imcb.12480] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 04/19/2021] [Accepted: 05/24/2021] [Indexed: 12/14/2022]
Abstract
Checkpoint signaling in the context of a functional DNA damage response is crucial for the prevention of oncogenic transformation of cells. Our immune system, though, takes the risk of attenuated checkpoint responses during immunoglobulin diversification. B cells undergo continuous DNA damage and error-prone repair of their immunoglobulin genes during the process of somatic hypermutation. An accompanying attenuation of the DNA damage response via the ATR-Chk1 axis in B cells is believed to allow for a better DNA damage tolerance and for evasion of apoptosis, so as to ensure mutations to be passed on. We sought to determine whether the downregulation of Chk1 could also directly influence the process of hypermutation in vivo by altering the relative activity of error-prone DNA repair pathways. We analyzed the humoral response and the hypermutation process in mice whose B cells express reduced levels of the Chk1 protein. We found that Chk1 heterozygosity limits the accumulation of mutations in the immunoglobulin loci, likely by impacting on the survival of B cells as they accumulate DNA damage. Nevertheless, we unveiled an unanticipated role for Chk1 downregulation in favoring A/T mutagenesis at the antibody-variable regions during hypermutation. Even though immunoglobulin mutagenesis was found to be reduced, Chk1 signaling attenuation allows for sustained mutagenesis outside the immunoglobulin loci. Our study thus reveals that a proper Chk1 dosage is crucial for adequate somatic hypermutation in B cells.
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Affiliation(s)
- Amanda Bello
- Department of Cell Biology, Institute of Biochemistry and Biophysics, School of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Berit Jungnickel
- Department of Cell Biology, Institute of Biochemistry and Biophysics, School of Biological Sciences, Friedrich Schiller University, Jena, Germany
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9
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Maiorano D, El Etri J, Franchet C, Hoffmann JS. Translesion Synthesis or Repair by Specialized DNA Polymerases Limits Excessive Genomic Instability upon Replication Stress. Int J Mol Sci 2021; 22:3924. [PMID: 33920223 PMCID: PMC8069355 DOI: 10.3390/ijms22083924] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/02/2021] [Accepted: 04/06/2021] [Indexed: 12/15/2022] Open
Abstract
DNA can experience "replication stress", an important source of genome instability, induced by various external or endogenous impediments that slow down or stall DNA synthesis. While genome instability is largely documented to favor both tumor formation and heterogeneity, as well as drug resistance, conversely, excessive instability appears to suppress tumorigenesis and is associated with improved prognosis. These findings support the view that karyotypic diversity, necessary to adapt to selective pressures, may be limited in tumors so as to reduce the risk of excessive instability. This review aims to highlight the contribution of specialized DNA polymerases in limiting extreme genetic instability by allowing DNA replication to occur even in the presence of DNA damage, to either avoid broken forks or favor their repair after collapse. These mechanisms and their key regulators Rad18 and Polθ not only offer diversity and evolutionary advantage by increasing mutagenic events, but also provide cancer cells with a way to escape anti-cancer therapies that target replication forks.
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Affiliation(s)
- Domenico Maiorano
- Institute of Human Genetics, UMR9002, CNRS-University of Montpellier, 34396 Montpellier, France; (D.M.); (J.E.E.)
| | - Jana El Etri
- Institute of Human Genetics, UMR9002, CNRS-University of Montpellier, 34396 Montpellier, France; (D.M.); (J.E.E.)
| | - Camille Franchet
- Laboratoire D’Excellence Toulouse Cancer (TOUCAN), Laboratoire de Pathologie, Institut Universitaire du Cancer-Toulouse, Oncopole, 1 Avenue Irène-Joliot-Curie, 31059 Toulouse, France;
| | - Jean-Sébastien Hoffmann
- Laboratoire D’Excellence Toulouse Cancer (TOUCAN), Laboratoire de Pathologie, Institut Universitaire du Cancer-Toulouse, Oncopole, 1 Avenue Irène-Joliot-Curie, 31059 Toulouse, France;
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10
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Nayak S, Calvo JA, Cantor SB. Targeting translesion synthesis (TLS) to expose replication gaps, a unique cancer vulnerability. Expert Opin Ther Targets 2021; 25:27-36. [PMID: 33416413 PMCID: PMC7837368 DOI: 10.1080/14728222.2021.1864321] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/11/2020] [Indexed: 02/09/2023]
Abstract
Introduction: Translesion synthesis (TLS) is a DNA damage tolerance (DDT) mechanism that employs error-prone polymerases to bypass replication blocking DNA lesions, contributing to a gain in mutagenesis and chemo-resistance. However, recent findings illustrate an emerging role for TLS in replication gap suppression (RGS), distinct from its role in post-replication gap filling. Here, TLS protects cells from replication stress (RS)-induced toxic single-stranded DNA (ssDNA) gaps that accumulate in the wake of active replication. Intriguingly, TLS-mediated RGS is specifically observed in several cancer cell lines and contributes to their survival. Thus, targeting TLS has the potential to uniquely eradicate tumors without harming non-cancer tissues. Areas Covered: This review provides an innovative perspective on the role of TLS beyond its canonical function of lesion bypass or post-replicative gap filling. We provide a comprehensive analysis that underscores the emerging role of TLS as a cancer adaptation necessary to overcome the replication stress response (RSR), an anti-cancer barrier. Expert Opinion: TLS RGS is critical for tumorigenesis and is a new hallmark of cancer. Although the exact mechanism and extent of TLS dependency in cancer is still emerging, TLS inhibitors have shown promise as an anti-cancer therapy in selectively targeting this unique cancer vulnerability.
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Affiliation(s)
- Sumeet Nayak
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School , Worcester, MA USA
| | - Jennifer A Calvo
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School , Worcester, MA USA
| | - Sharon B Cantor
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School , Worcester, MA USA
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11
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Ma X, Tang TS, Guo C. Regulation of translesion DNA synthesis in mammalian cells. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:680-692. [PMID: 31983077 DOI: 10.1002/em.22359] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/29/2019] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
The genomes of all living cells are under endogenous and exogenous attacks every day, causing diverse genomic lesions. Most of the lesions can be timely repaired by multiple DNA repair pathways. However, some may persist during S-phase, block DNA replication, and challenge genome integrity. Eukaryotic cells have evolved DNA damage tolerance (DDT) to mitigate the lethal effects of arrested DNA replication without prior removal of the offending DNA damage. As one important mode of DDT, translesion DNA synthesis (TLS) utilizes multiple low-fidelity DNA polymerases to incorporate nucleotides opposite DNA lesions to maintain genome integrity. Three different mechanisms have been proposed to regulate the polymerase switching between high-fidelity DNA polymerases in the replicative machinery and one or more specialized enzymes. Additionally, it is known that proliferating cell nuclear antigen (PCNA) mono-ubiquitination is essential for optimal TLS. Given its error-prone property, TLS is closely associated with spontaneous and drug-induced mutations in cells, which can potentially lead to tumorigenesis and chemotherapy resistance. Therefore, TLS process must be tightly modulated to avoid unwanted mutagenesis. In this review, we will focus on polymerase switching and PCNA mono-ubiquitination, the two key events in TLS pathway in mammalian cells, and summarize current understandings of regulation of TLS process at the levels of protein-protein interactions, post-translational modifications as well as transcription and noncoding RNAs. Environ. Mol. Mutagen. 61:680-692, 2020. © 2020 Wiley Periodicals, Inc.
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Affiliation(s)
- Xiaolu Ma
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
| | - Caixia Guo
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
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12
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Gralewska P, Gajek A, Marczak A, Rogalska A. Participation of the ATR/CHK1 pathway in replicative stress targeted therapy of high-grade ovarian cancer. J Hematol Oncol 2020; 13:39. [PMID: 32316968 PMCID: PMC7175546 DOI: 10.1186/s13045-020-00874-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/08/2020] [Indexed: 12/15/2022] Open
Abstract
Ovarian cancer is one of the most lethal gynecologic malignancies reported throughout the world. The initial, standard-of-care, adjuvant chemotherapy in epithelial ovarian cancer is usually a platinum drug, such as cisplatin or carboplatin, combined with a taxane. However, despite surgical removal of the tumor and initial high response rates to first-line chemotherapy, around 80% of women will develop cancer recurrence. Effective strategies, including chemotherapy and new research models, are necessary to improve the prognosis. The replication stress response (RSR) is characteristic of the development of tumors, including ovarian cancer. Hence, RSR pathway and DNA repair proteins have emerged as a new area for anticancer drug development. Although clinical trials have shown poly (ADP-ribose) polymerase inhibitors (PARPi) response rates of around 40% in women who carry a mutation in the BRCA1/2 genes, PARPi is responsible for tumor suppression, but not for complete tumor regression. Recent reports suggest that cells with impaired homologous recombination (HR) activities due to mutations in TP53 gene or specific DNA repair proteins are specifically sensitive to ataxia telangiectasia and Rad3-related protein (ATR) inhibitors. Replication stress activates DNA repair checkpoint proteins (ATR, CHK1), which prevent further DNA damage. This review describes the use of DNA repair checkpoint inhibitors as single agents and strategies combining these inhibitors with DNA-damaging compounds for ovarian cancer therapy, as well as the new platforms used for optimizing ovarian cancer therapy.
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Affiliation(s)
- Patrycja Gralewska
- Department of Medical Biophysics, Faculty of Biology and Environmental Protection, Institute of Biophysics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - Arkadiusz Gajek
- Department of Medical Biophysics, Faculty of Biology and Environmental Protection, Institute of Biophysics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - Agnieszka Marczak
- Department of Medical Biophysics, Faculty of Biology and Environmental Protection, Institute of Biophysics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland
| | - Aneta Rogalska
- Department of Medical Biophysics, Faculty of Biology and Environmental Protection, Institute of Biophysics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland.
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13
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Rai R, Gu P, Broton C, Kumar-Sinha C, Chen Y, Chang S. The Replisome Mediates A-NHEJ Repair of Telomeres Lacking POT1-TPP1 Independently of MRN Function. Cell Rep 2019; 29:3708-3725.e5. [PMID: 31825846 PMCID: PMC7001145 DOI: 10.1016/j.celrep.2019.11.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 09/22/2019] [Accepted: 11/04/2019] [Indexed: 02/07/2023] Open
Abstract
Telomeres use shelterin to protect chromosome ends from activating the DNA damage sensor MRE11-RAD50-NBS1 (MRN), repressing ataxia-telangiectasia, mutated (ATM) and ATM and Rad3-related (ATR) dependent DNA damage checkpoint responses. The MRE11 nuclease is thought to be essential for the resection of the 5' C-strand to generate the microhomologies necessary for alternative non-homologous end joining (A-NHEJ) repair. In the present study, we uncover DNA damage signaling and repair pathways engaged by components of the replisome complex to repair dysfunctional telomeres. In cells lacking MRN, single-stranded telomeric overhangs devoid of POT1-TPP1 do not recruit replication protein A (RPA), ATR-interacting protein (ATRIP), and RAD 51. Rather, components of the replisome complex, including Claspin, Proliferating cell nuclear antigen (PCNA), and Downstream neighbor of SON (DONSON), initiate DNA-PKcs-mediated p-CHK1 activation and A-NHEJ repair. In addition, Claspin directly interacts with TRF2 and recruits EXO1 to newly replicated telomeres to promote 5' end resection. Our data indicate that MRN is dispensable for the repair of dysfunctional telomeres lacking POT1-TPP1 and highlight the contributions of the replisome in telomere repair.
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Affiliation(s)
- Rekha Rai
- Departments of Laboratory Medicine, Yale University School of Medicine, 330 Cedar St., New Haven, CT 06520, USA.
| | - Peili Gu
- Departments of Laboratory Medicine, Yale University School of Medicine, 330 Cedar St., New Haven, CT 06520, USA
| | - Cayla Broton
- Departments of Laboratory Medicine, Yale University School of Medicine, 330 Cedar St., New Haven, CT 06520, USA; Tri-Institutional MD/PhD Program, Weill Cornell Medical College, New York, NY 10065, USA
| | - Chandan Kumar-Sinha
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Yong Chen
- National Center for Protein Science Shanghai, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China
| | - Sandy Chang
- Departments 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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14
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Masuda Y, Masutani C. Spatiotemporal regulation of PCNA ubiquitination in damage tolerance pathways. Crit Rev Biochem Mol Biol 2019; 54:418-442. [PMID: 31736364 DOI: 10.1080/10409238.2019.1687420] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
DNA is constantly exposed to a wide variety of exogenous and endogenous agents, and most DNA lesions inhibit DNA synthesis. To cope with such problems during replication, cells have molecular mechanisms to resume DNA synthesis in the presence of DNA lesions, which are known as DNA damage tolerance (DDT) pathways. The concept of ubiquitination-mediated regulation of DDT pathways in eukaryotes was established via genetic studies in the yeast Saccharomyces cerevisiae, in which two branches of the DDT pathway are regulated via ubiquitination of proliferating cell nuclear antigen (PCNA): translesion DNA synthesis (TLS) and homology-dependent repair (HDR), which are stimulated by mono- and polyubiquitination of PCNA, respectively. Over the subsequent nearly two decades, significant progress has been made in understanding the mechanisms that regulate DDT pathways in other eukaryotes. Importantly, TLS is intrinsically error-prone because of the miscoding nature of most damaged nucleotides and inaccurate replication of undamaged templates by TLS polymerases (pols), whereas HDR is theoretically error-free because the DNA synthesis is thought to be predominantly performed by pol δ, an accurate replicative DNA pol, using the undamaged sister chromatid as its template. Thus, the regulation of the choice between the TLS and HDR pathways is critical to determine the appropriate biological outcomes caused by DNA damage. In this review, we summarize our current understanding of the species-specific regulatory mechanisms of PCNA ubiquitination and how cells choose between TLS and HDR. We then provide a hypothetical model for the spatiotemporal regulation of DDT pathways in human cells.
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Affiliation(s)
- Yuji Masuda
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.,Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Chikahide Masutani
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.,Graduate School of Medicine, Nagoya University, Nagoya, Japan
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15
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González Besteiro MA, Calzetta NL, Loureiro SM, Habif M, Bétous R, Pillaire MJ, Maffia A, Sabbioneda S, Hoffmann JS, Gottifredi V. Chk1 loss creates replication barriers that compromise cell survival independently of excess origin firing. EMBO J 2019; 38:e101284. [PMID: 31294866 DOI: 10.15252/embj.2018101284] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 06/11/2019] [Accepted: 06/19/2019] [Indexed: 01/18/2023] Open
Abstract
The effectiveness of checkpoint kinase 1 (Chk1) inhibitors at killing cancer cells is considered to be fully dependent on their effect on DNA replication initiation. Chk1 inhibition boosts origin firing, presumably limiting the availability of nucleotides and in turn provoking the slowdown and subsequent collapse of forks, thus decreasing cell viability. Here we show that slow fork progression in Chk1-inhibited cells is not an indirect effect of excess new origin firing. Instead, fork slowdown results from the accumulation of replication barriers, whose bypass is impeded by CDK-dependent phosphorylation of the specialized DNA polymerase eta (Polη). Also in contrast to the linear model, the accumulation of DNA damage in Chk1-deficient cells depends on origin density but is largely independent of fork speed. Notwithstanding this, origin dysregulation contributes only mildly to the poor proliferation rates of Chk1-depleted cells. Moreover, elimination of replication barriers by downregulation of helicase components, but not their bypass by Polη, improves cell survival. Our results thus shed light on the molecular basis of the sensitivity of tumors to Chk1 inhibition.
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Affiliation(s)
- Marina A González Besteiro
- Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Nicolás L Calzetta
- Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Sofía M Loureiro
- Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Martín Habif
- Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Rémy Bétous
- Equipe «Labellisée LA LIGUE CONTRE LE CANCER», Laboratoire d'Excellence Toulouse Cancer LABEX TOUCAN - Cancer Research Center of Toulouse, Inserm U1037, CNRS ERL5294, University Paul Sabatier, Toulouse, France
| | - Marie-Jeanne Pillaire
- Equipe «Labellisée LA LIGUE CONTRE LE CANCER», Laboratoire d'Excellence Toulouse Cancer LABEX TOUCAN - Cancer Research Center of Toulouse, Inserm U1037, CNRS ERL5294, University Paul Sabatier, Toulouse, France
| | - Antonio Maffia
- Istituto di Genetica Molecolare "Luigi Luca Cavalli-Sforza" - CNR, Pavia, Italy
| | - Simone Sabbioneda
- Istituto di Genetica Molecolare "Luigi Luca Cavalli-Sforza" - CNR, Pavia, Italy
| | - Jean-Sébastien Hoffmann
- Equipe «Labellisée LA LIGUE CONTRE LE CANCER», Laboratoire d'Excellence Toulouse Cancer LABEX TOUCAN - Cancer Research Center of Toulouse, Inserm U1037, CNRS ERL5294, University Paul Sabatier, Toulouse, France
| | - Vanesa Gottifredi
- Fundación Instituto Leloir - Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
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16
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Azenha D, Lopes MC, Martins TC. Claspin: From replication stress and DNA damage responses to cancer therapy. DNA Repair (Amst) 2019; 115:203-246. [DOI: 10.1016/bs.apcsb.2018.10.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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17
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Leung W, Baxley RM, Moldovan GL, Bielinsky AK. Mechanisms of DNA Damage Tolerance: Post-Translational Regulation of PCNA. Genes (Basel) 2018; 10:genes10010010. [PMID: 30586904 PMCID: PMC6356670 DOI: 10.3390/genes10010010] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 12/18/2018] [Accepted: 12/19/2018] [Indexed: 12/12/2022] Open
Abstract
DNA damage is a constant source of stress challenging genomic integrity. To ensure faithful duplication of our genomes, mechanisms have evolved to deal with damage encountered during replication. One such mechanism is referred to as DNA damage tolerance (DDT). DDT allows for replication to continue in the presence of a DNA lesion by promoting damage bypass. Two major DDT pathways exist: error-prone translesion synthesis (TLS) and error-free template switching (TS). TLS recruits low-fidelity DNA polymerases to directly replicate across the damaged template, whereas TS uses the nascent sister chromatid as a template for bypass. Both pathways must be tightly controlled to prevent the accumulation of mutations that can occur from the dysregulation of DDT proteins. A key regulator of error-prone versus error-free DDT is the replication clamp, proliferating cell nuclear antigen (PCNA). Post-translational modifications (PTMs) of PCNA, mainly by ubiquitin and SUMO (small ubiquitin-like modifier), play a critical role in DDT. In this review, we will discuss the different types of PTMs of PCNA and how they regulate DDT in response to replication stress. We will also cover the roles of PCNA PTMs in lagging strand synthesis, meiotic recombination, as well as somatic hypermutation and class switch recombination.
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Affiliation(s)
- Wendy Leung
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Ryan M Baxley
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
| | - George-Lucian Moldovan
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
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18
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Moreno NC, Garcia CCM, Rocha CRR, Munford V, Menck CFM. ATR/Chk1 Pathway is Activated by Oxidative Stress in Response to UVA Light in Human Xeroderma Pigmentosum Variant Cells. Photochem Photobiol 2018; 95:345-354. [PMID: 30362123 DOI: 10.1111/php.13041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 10/03/2018] [Indexed: 12/14/2022]
Abstract
The crucial role of DNA polymerase eta in protecting against sunlight-induced tumors is evidenced in Xeroderma Pigmentosum Variant (XP-V) patients, who carry mutations in this protein and present increased frequency of skin cancer. XP-V cellular phenotypes may be aggravated if proteins of DNA damage response (DDR) pathway are blocked, as widely demonstrated by experiments with UVC light and caffeine. However, little is known about the participation of DDR in XP-V cells exposed to UVA light, the wavelengths patients are mostly exposed. Here, we demonstrate the participation of ATR kinase in protecting XP-V cells after receiving low UVA doses using a specific inhibitor, with a remarkable increase in sensitivity and γH2AX signaling. Corroborating ATR participation in UVA-DDR, a significant increase in Chk1 protein phosphorylation, as well as S-phase cell cycle arrest, is also observed. Moreover, the participation of oxidative stress is supported by the antioxidant action of N-acetylcysteine (NAC), which significantly protects XP-V cells from UVA light, even in the presence of the ATR inhibitor. These findings indicate that the ATR/Chk1 pathway is activated to control UVA-induced oxidatively generated DNA damage and emphasizes the role of ATR kinase as a mediator of genomic stability in pol eta defective cells.
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Affiliation(s)
- Natália Cestari Moreno
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | | | | | - Veridiana Munford
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
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19
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Kantidze OL, Velichko AK, Luzhin AV, Petrova NV, Razin SV. Synthetically Lethal Interactions of ATM, ATR, and DNA-PKcs. Trends Cancer 2018; 4:755-768. [PMID: 30352678 DOI: 10.1016/j.trecan.2018.09.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 09/10/2018] [Accepted: 09/18/2018] [Indexed: 12/12/2022]
Abstract
Synthetic lethality occurs when simultaneous perturbations of two genes or molecular processes result in a loss of cell viability. The number of known synthetically lethal interactions is growing steadily. We review here synthetically lethal interactions of ataxia-telangiectasia mutated (ATM), ATM- and Rad3-related (ATR), and DNA-dependent protein kinase catalytic subunit (DNA-PKcs). These kinases are appropriate for synthetic lethal therapies because their genes are frequently mutated in cancer, and specific inhibitors are currently in clinical trials. Understanding synthetically lethal interactions of a particular gene or gene family can facilitate predicting new synthetically lethal interactions, therapy toxicity, and mechanisms of resistance, as well as defining the spectrum of tumors amenable to these therapeutic approaches.
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Affiliation(s)
- Omar L Kantidze
- Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia; LFR2O, Institute Gustave Roussy, Villejuif, France.
| | - Artem K Velichko
- Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia; Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Artem V Luzhin
- Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia
| | | | - Sergey V Razin
- Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia; LFR2O, Institute Gustave Roussy, Villejuif, France; Lomonosov Moscow State University, Moscow, Russia
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20
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Whiteaker JR, Zhao L, Saul R, Kaczmarczyk JA, Schoenherr RM, Moore HD, Jones-Weinert C, Ivey RG, Lin C, Hiltke T, Reding KW, Whiteley G, Wang P, Paulovich AG. A Multiplexed Mass Spectrometry-Based Assay for Robust Quantification of Phosphosignaling in Response to DNA Damage. Radiat Res 2018; 189:505-518. [PMID: 29474155 PMCID: PMC5939939 DOI: 10.1667/rr14963.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A lack of analytically robust and multiplexed assays has hampered studies of the large, branched phosphosignaling network responsive to DNA damage. To address this need, we developed and fully analytically characterized a 62-plex assay quantifying protein expression and post-translational modification (phosphorylation and ubiquitination) after induction of DNA damage. The linear range was over 3 orders of magnitude, the median inter-assay variability was 10% CV and the vast majority (∼85%) of assays were stable after extended storage. The multiplexed assay was applied in proof-of-principle studies to quantify signaling after exposure to genotoxic stress (ionizing radiation and 4-nitroquinoline 1-oxide) in immortalized cell lines and primary human cells. The effects of genomic variants and pharmacologic kinase inhibition (ATM/ATR) were profiled using the assay. This study demonstrates the utility of a quantitative multiplexed assay for studying cellular signaling dynamics, and the potential application to studies on inter-individual variation in the radiation response.
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Affiliation(s)
- Jeffrey R. Whiteaker
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washingon
| | - Lei Zhao
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washingon
| | - Rick Saul
- Antibody Characterization Laboratory, Leidos Biochemical Research, Inc., Frederick National Laboratory for Cancer Research ATRF, Frederick, Maryland
| | - Jan A. Kaczmarczyk
- Antibody Characterization Laboratory, Leidos Biochemical Research, Inc., Frederick National Laboratory for Cancer Research ATRF, Frederick, Maryland
| | - Regine M. Schoenherr
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washingon
| | - Heather D. Moore
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washingon
| | - Corey Jones-Weinert
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washingon
| | - Richard G. Ivey
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washingon
| | - Chenwei Lin
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washingon
| | - Tara Hiltke
- Office of Cancer Clinical Proteomics Research, National Cancer Institute, Bethesda, Maryland
| | - Kerryn W. Reding
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washingon
- School of Public Health, University of Washington, Seattle, Washington
| | - Gordon Whiteley
- Antibody Characterization Laboratory, Leidos Biochemical Research, Inc., Frederick National Laboratory for Cancer Research ATRF, Frederick, Maryland
| | - Pei Wang
- Department of Genetics and Genomic Sciences, Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Amanda G. Paulovich
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washingon
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21
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Zhu X, Ma X, Tu Y, Huang M, Liu H, Wang F, Gong J, Wang J, Li X, Chen Q, Shen H, Zhu S, Wang Y, Liu Y, Guo C, Tang TS. Parkin regulates translesion DNA synthesis in response to UV radiation. Oncotarget 2018; 8:36423-36437. [PMID: 28430587 PMCID: PMC5482665 DOI: 10.18632/oncotarget.16855] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/27/2017] [Indexed: 01/12/2023] Open
Abstract
Deficiency of Parkin is a major cause of early-onset Parkinson's disease (PD). Notably, PD patients also exhibit a significantly higher risk in melanoma and other skin tumors, while the mechanism remains largely unknown. In this study, we show that depletion of Parkin causes compromised cell viability and genome stability after ultraviolet (UV) radiation. We demonstrate that Parkin promotes efficient Rad18-dependent proliferating cell nuclear antigen (PCNA) monoubiquitination by facilitating the formation of Replication protein A (RPA)-coated ssDNA upon UV radiation. Furthermore, Parkin is found to physically interact with NBS1 (Nijmegen breakage syndrome 1), and to be required for optimal recruitment of NBS1 and DNA polymerase eta (Polη) to UV-induced damage sites. Consequently, depletion of Parkin leads to increased UV-induced mutagenesis. These findings unveil an important role of Parkin in protecting genome stability through positively regulating translesion DNA synthesis (TLS) upon UV damage, providing a novel mechanistic link between Parkin deficiency and predisposition to skin cancers in PD patients.
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Affiliation(s)
- Xuefei Zhu
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaolu Ma
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Yingfeng Tu
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Min Huang
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Hongmei Liu
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Fengli Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Juanjuan Gong
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Jiuqiang Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaoling Li
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Qian Chen
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Hongyan Shen
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Shu Zhu
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Yun Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Yang Liu
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Caixia Guo
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
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22
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Azenha D, Lopes MC, Martins TC. Claspin functions in cell homeostasis-A link to cancer? DNA Repair (Amst) 2017; 59:27-33. [PMID: 28942358 DOI: 10.1016/j.dnarep.2017.09.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 09/06/2017] [Indexed: 10/18/2022]
Abstract
Cancer remains one of the leading causes of mortality worldwide. Most cancers present high degrees of genomic instability. DNA damage and replication checkpoints function as barriers to halt cell cycle progression until damage is resolved, preventing the perpetuation of errors. Activation of these checkpoints is critically dependent on Claspin, an adaptor protein that mediates the phosphorylation of the effector kinase Chk1 by ATR. However, Claspin also performs other roles related to the protection and maintenance of cell and genome integrity. For instance, following DNA damage and checkpoint activation, Claspin bridges checkpoint responses to DNA repair or to apoptosis. During DNA replication, Claspin acts a sensor and couples DNA unwinding to strand polymerization, and may also indirectly regulate replication initiation at firing origins. As Claspin participates in several processes that are vital to maintenance of cell homeostasis, its function is tightly regulated at multiple levels. Nevertheless, little is known about its role in cancer. Accumulating evidence suggests that Claspin inactivation could be an essential event during carcinogenesis, indicating that Claspin may function as a tumour suppressor. In this review, we will examine the functions of Claspin and how its deregulation may contribute to cancer initiation and progression. To conclude, we will discuss means by which Claspin can be targeted for cancer therapy.
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Affiliation(s)
- Diana Azenha
- Faculdade de Farmácia da Universidade de Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal; Centro de Neurociências e Biologia Celular, Universidade de Coimbra, Rua Larga, Faculdade de Medicina, Pólo I, 1º andar, 3004-504 Coimbra, Portugal; Instituto Português de Oncologia de Coimbra de Francisco Gentil, Av. Bissaya Barreto 98, Apartado 2005, 3000-651, Coimbra, Portugal.
| | - Maria Celeste Lopes
- Faculdade de Farmácia da Universidade de Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal; Centro de Neurociências e Biologia Celular, Universidade de Coimbra, Rua Larga, Faculdade de Medicina, Pólo I, 1º andar, 3004-504 Coimbra, Portugal.
| | - Teresa C Martins
- Centro de Neurociências e Biologia Celular, Universidade de Coimbra, Rua Larga, Faculdade de Medicina, Pólo I, 1º andar, 3004-504 Coimbra, Portugal; Instituto Português de Oncologia de Coimbra de Francisco Gentil, Av. Bissaya Barreto 98, Apartado 2005, 3000-651, Coimbra, Portugal.
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23
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Tu Y, Liu H, Zhu X, Shen H, Ma X, Wang F, Huang M, Gong J, Li X, Wang Y, Guo C, Tang TS. Ataxin-3 promotes genome integrity by stabilizing Chk1. Nucleic Acids Res 2017; 45:4532-4549. [PMID: 28180282 PMCID: PMC5416811 DOI: 10.1093/nar/gkx095] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/07/2017] [Indexed: 12/27/2022] Open
Abstract
The Chk1 protein is essential for genome integrity maintenance and cell survival in eukaryotic cells. After prolonged replication stress, Chk1 can be targeted for proteasomal degradation to terminate checkpoint signaling after DNA repair finishes. To ensure proper activation of DNA damage checkpoint and DNA repair signaling, a steady-state level of Chk1 needs to be retained under physiological conditions. Here, we report a dynamic signaling pathway that tightly regulates Chk1 stability. Under unperturbed conditions and upon DNA damage, ataxin-3 (ATX3) interacts with Chk1 and protects it from DDB1/CUL4A- and FBXO6/CUL1-mediated polyubiquitination and subsequent degradation, thereby promoting DNA repair and checkpoint signaling. Under prolonged replication stress, ATX3 dissociates from Chk1, concomitant with a stronger binding between Chk1 and its E3 ligase, which causes Chk1 proteasomal degradation. ATX3 deficiency results in pronounced reduction of Chk1 abundance, compromised DNA damage response, G2/M checkpoint defect and decreased cell survival after replication stress, which can all be rescued by ectopic expression of ATX3. Taken together, these findings reveal ATX3 to be a novel deubiquitinase of Chk1, providing a new mechanism of Chk1 stabilization in genome integrity maintenance.
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Affiliation(s)
- Yingfeng Tu
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
- These authors contributed equally to the work as first authors
| | - Hongmei Liu
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
- These authors contributed equally to the work as first authors
| | - Xuefei Zhu
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
- These authors contributed equally to the work as first authors
| | - Hongyan Shen
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaolu Ma
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Fengli Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Min Huang
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Juanjuan Gong
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaoling Li
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Yun Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
| | - Caixia Guo
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
- To whom correspondence should be addressed. Tel: +86 10 64807296; Fax: +86 10 64807313; . Correspondence may also be addressed to Caixia Guo. Tel: +86 10 84097646; Fax: +86 10 84097720;
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China
- To whom correspondence should be addressed. Tel: +86 10 64807296; Fax: +86 10 64807313; . Correspondence may also be addressed to Caixia Guo. Tel: +86 10 84097646; Fax: +86 10 84097720;
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Choe KN, Moldovan GL. Forging Ahead through Darkness: PCNA, Still the Principal Conductor at the Replication Fork. Mol Cell 2017; 65:380-392. [PMID: 28157503 DOI: 10.1016/j.molcel.2016.12.020] [Citation(s) in RCA: 203] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 11/28/2016] [Accepted: 12/21/2016] [Indexed: 10/20/2022]
Abstract
Proliferating cell nuclear antigen (PCNA) lies at the center of the faithful duplication of eukaryotic genomes. With its distinctive doughnut-shaped molecular structure, PCNA was originally studied for its role in stimulating DNA polymerases. However, we now know that PCNA does much more than promote processive DNA synthesis. Because of the complexity of the events involved, cellular DNA replication poses major threats to genomic integrity. Whatever predicament lies ahead for the replication fork, PCNA is there to orchestrate the events necessary to handle it. Through its many protein interactions and various post-translational modifications, PCNA has far-reaching impacts on a myriad of cellular functions.
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Affiliation(s)
- Katherine N Choe
- 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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25
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FANCM, BRCA1, and BLM cooperatively resolve the replication stress at the ALT telomeres. Proc Natl Acad Sci U S A 2017; 114:E5940-E5949. [PMID: 28673972 DOI: 10.1073/pnas.1708065114] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
In the mammalian genome, certain genomic loci/regions pose greater challenges to the DNA replication machinery (i.e., the replisome) than others. Such known genomic loci/regions include centromeres, common fragile sites, subtelomeres, and telomeres. However, the detailed mechanism of how mammalian cells cope with the replication stress at these loci/regions is largely unknown. Here we show that depletion of FANCM, or of one of its obligatory binding partners, FAAP24, MHF1, and MHF2, induces replication stress primarily at the telomeres of cells that use the alternative lengthening of telomeres (ALT) pathway as their telomere maintenance mechanism. Using the telomere-specific single-molecule analysis of replicated DNA technique, we found that depletion of FANCM dramatically reduces the replication efficiency at ALT telomeres. We further show that FANCM, BRCA1, and BLM are actively recruited to the ALT telomeres that are experiencing replication stress and that the recruitment of BRCA1 and BLM to these damaged telomeres is interdependent and is regulated by both ATR and Chk1. Mechanistically, we demonstrated that, in FANCM-depleted ALT cells, BRCA1 and BLM help to resolve the telomeric replication stress by stimulating DNA end resection and homologous recombination (HR). Consistent with their roles in resolving the replication stress induced by FANCM deficiency, simultaneous depletion of BLM and FANCM, or of BRCA1 and FANCM, leads to increased micronuclei formation and synthetic lethality in ALT cells. We propose that these synthetic lethal interactions can be explored for targeting the ALT cancers.
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26
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Kanao R, Masutani C. Regulation of DNA damage tolerance in mammalian cells by post-translational modifications of PCNA. Mutat Res 2017; 803-805:82-88. [PMID: 28666590 DOI: 10.1016/j.mrfmmm.2017.06.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 05/25/2017] [Accepted: 06/19/2017] [Indexed: 11/29/2022]
Abstract
DNA damage tolerance pathways, which include translesion DNA synthesis (TLS) and template switching, are crucial for prevention of DNA replication arrest and maintenance of genomic stability. However, these pathways utilize error-prone DNA polymerases or template exchange between sister DNA strands, and consequently have the potential to induce mutations or chromosomal rearrangements. Post-translational modifications of proliferating cell nuclear antigen (PCNA) play important roles in controlling these pathways. For example, TLS is mediated by mono-ubiquitination of PCNA at lysine 164, for which RAD6-RAD18 is the primary E2-E3 complex. Elaborate protein-protein interactions between mono-ubiquitinated PCNA and Y-family DNA polymerases constitute the core of the TLS regulatory system, and enhancers of PCNA mono-ubiquitination and de-ubiquitinating enzymes finely regulate TLS and suppress TLS-mediated mutagenesis. The template switching pathway is promoted by K63-linked poly-ubiquitination of PCNA at lysine 164. Poly-ubiquitination is achieved by a coupled reaction mediated by two sets of E2-E3 complexes, RAD6-RAD18 and MMS2-UBC13-HTLF/SHPRH. In addition to these mono- and poly-ubiquitinations, simultaneous mono-ubiquitinations on multiple units of the PCNA homotrimeric ring promote an unidentified damage tolerance mechanism that remains to be fully characterized. Furthermore, SUMOylation of PCNA in mammalian cells can negatively regulate recombination. Other modifications, including ISGylation, acetylation, methylation, or phosphorylation, may also play roles in DNA damage tolerance and control of genomic stability.
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Affiliation(s)
- Rie Kanao
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Chikahide Masutani
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.
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27
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George E, Kim H, Krepler C, Wenz B, Makvandi M, Tanyi JL, Brown E, Zhang R, Brafford P, Jean S, Mach RH, Lu Y, Mills GB, Herlyn M, Morgan M, Zhang X, Soslow R, Drapkin R, Johnson N, Zheng Y, Cotsarelis G, Nathanson KL, Simpkins F. A patient-derived-xenograft platform to study BRCA-deficient ovarian cancers. JCI Insight 2017; 2:e89760. [PMID: 28097235 DOI: 10.1172/jci.insight.89760] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Approximately 50% of high-grade serous ovarian cancers (HGSOCs) have defects in genes involved in homologous recombination (HR) (i.e., BRCA1/2). Preclinical models to optimize therapeutic strategies for HR-deficient (HRD) HGSOC are lacking. We developed a preclinical platform for HRD HGSOCs that includes primary tumor cultures, patient-derived xenografts (PDXs), and molecular imaging. Models were characterized by immunohistochemistry, targeted sequencing, and reverse-phase protein array analysis. We also tested PDX tumor response to PARP, CHK1, and ATR inhibitors. Fourteen orthotopic HGSOC PDX models with BRCA mutations (BRCAMUT) were established with a 93% success rate. The orthotopic PDX model emulates the natural progression of HGSOC, including development of a primary ovarian tumor and metastasis to abdominal viscera. PDX response to standard chemotherapy correlated to that demonstrated in the patient. Pathogenic mutations and HGSOC markers were preserved after multiple mouse passages, indicating retention of underlying molecular mechanisms of carcinogenesis. A BRCA2MUT PDX with high p-CHK1 demonstrated a similar delay of tumor growth in response to PARP, CHK1, and ATR inhibitors. A poly (ADP-ribose) polymerase (PARP) inhibitor radiotracer correlated with PARP1 activity and showed response to PARP inhibition in the BRCA2MUT PDX model. In summary, the orthotopic HGSOC PDX represents a robust and reliable model to optimize therapeutic strategies for BRCAMUT HGSOC.
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Affiliation(s)
- Erin George
- Ovarian Cancer Research Center, Division of Gynecology Oncology, Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hyoung Kim
- Ovarian Cancer Research Center, Division of Gynecology Oncology, Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Brandon Wenz
- Oncogenomics, Abramson Cancer Center, Philadelphia, Pennsylvania, USA
| | - Mehran Makvandi
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Janos L Tanyi
- Ovarian Cancer Research Center, Division of Gynecology Oncology, Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Eric Brown
- Cancer Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Rugang Zhang
- The Wistar Institute, Philadelphia, Pennsylvania, USA
| | | | - Stephanie Jean
- Ovarian Cancer Research Center, Division of Gynecology Oncology, Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Robert H Mach
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Yiling Lu
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Gordon B Mills
- Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | | | - Mark Morgan
- Ovarian Cancer Research Center, Division of Gynecology Oncology, Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xiaochen Zhang
- Ovarian Cancer Research Center, Division of Gynecology Oncology, Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Robert Soslow
- Department of Pathology, Memorial Sloan Kettering, New York, New York, USA
| | - Ronny Drapkin
- Ovarian Cancer Research Center, Division of Gynecology Oncology, Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Neil Johnson
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
| | - Ying Zheng
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - George Cotsarelis
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Fiona Simpkins
- Ovarian Cancer Research Center, Division of Gynecology Oncology, Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,The Wistar Institute, Philadelphia, Pennsylvania, USA
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28
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Inhibition of ATR-dependent feedback activation of Chk1 sensitises cancer cells to Chk1 inhibitor monotherapy. Cancer Lett 2016; 383:41-52. [PMID: 27693461 DOI: 10.1016/j.canlet.2016.09.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 09/07/2016] [Accepted: 09/08/2016] [Indexed: 11/23/2022]
Abstract
The Chk1 and ATR kinases are critical mediators of the DNA damage response pathway and help protect cancer cells from endogenous and oncogene induced replication stress. Inhibitors of both kinases are currently being evaluated in clinical trials. Chk1 inhibition with V158411 increases DNA damage and activates the ATR, ATM and DNA-PKcs dependent DNA damage response pathways. Inhibiting ATR, ATM and/or DNA-PKcs has the potential to increase the therapeutic activity of Chk1 inhibitors. ATR inhibition but not ATM or DNA-PKcs inhibition potentiated the cytotoxicity of V158411 in p53 mutant and wild type human cancer cell lines. This increased cytotoxicity correlated with increased nuclear DNA damage and replication stress in a dose and time dependent manner. γH2AX induction following Chk1 inhibition protected cells from caspase-dependent apoptosis. Inhibition of ATR increased Chk1 inhibitor induced cell death independently of caspase activation. The effect of ATR, ATM and/or DNA-PK inhibition on Chk1 inhibitor induced replication stress was dependent on the concentration of Chk1 inhibitor. ATR inhibition potentiated Chk1 inhibitor induced replication stress and cytotoxicity via the abrogation of ATR-dependent feedback activation of Chk1 induced by Chk1 inhibitor generated replication stress. This study suggests that combining an ATR inhibitor to lower the threshold by which a Chk1 inhibitor induces replication stress, DNA damage and tumour cell death in a wide range of cancer types may be a useful clinical approach.
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29
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Abstract
The ATR (ATM and rad3-related) pathway is crucial for proliferation, responding to DNA replication stress and DNA damage. This critical signaling pathway is carefully orchestrated through a multistep process requiring initial priming of ATR prior to damage, recruitment of ATR to DNA damage lesions, activation of ATR signaling, and, finally, modulation of ATR activity through a variety of post-translational modifications. Following activation, ATR functions in several vital cellular processes, including suppression of replication origin firing, promotion of deoxynucleotide synthesis and replication fork restart, prevention of double-stranded DNA break formation, and avoidance of replication catastrophe and mitotic catastrophe. In many cancers, tumor cells have increased dependence on ATR signaling for survival, making ATR a promising target for cancer therapy. Tumor cells compromised in DNA repair pathways or DNA damage checkpoints, cells reliant on homologous recombination, and cells with increased replication stress are particularly sensitive to ATR inhibition. Understanding ATR signaling and modulation is essential to unraveling which tumors have increased dependence on ATR signaling as well as how the ATR pathway can best be exploited for targeted cancer therapy.
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Affiliation(s)
- Stephanie A Yazinski
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, Massachusetts 02129;
| | - Lee Zou
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, Massachusetts 02129; .,Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02115
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30
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Yang CC, Suzuki M, Yamakawa S, Uno S, Ishii A, Yamazaki S, Fukatsu R, Fujisawa R, Sakimura K, Tsurimoto T, Masai H. Claspin recruits Cdc7 kinase for initiation of DNA replication in human cells. Nat Commun 2016; 7:12135. [PMID: 27401717 PMCID: PMC4945878 DOI: 10.1038/ncomms12135] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 06/03/2016] [Indexed: 11/09/2022] Open
Abstract
Claspin transmits replication stress signal from ATR to Chk1 effector kinase as a mediator. It also plays a role in efficient replication fork progression during normal growth. Here we have generated conditional knockout of Claspin and show that Claspin knockout mice are dead by E12.5 and Claspin knockout mouse embryonic fibroblast (MEF) cells show defect in S phase. Using the mutant cell lines, we report the crucial roles of the acidic patch (AP) near the C terminus of Claspin in initiation of DNA replication. Cdc7 kinase binds to AP and this binding is required for phosphorylation of Mcm. AP is involved also in intramolecular interaction with a N-terminal segment, masking the DNA-binding domain and a newly identified PIP motif, and Cdc7-mediated phosphorylation reduces the intramolecular interaction. Our results suggest a new role of Claspin in initiation of DNA replication during normal S phase through the recruitment of Cdc7 that facilitates phosphorylation of Mcm proteins. Claspin mediates the transmission of a replication-stress signal from ATR to Chk1 and is necessary for efficient fork progression. Here the authors demonstrate that the C-terminal acidic patch is important for this role due to its interaction with Cdc7.
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Affiliation(s)
- Chi-Chun Yang
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Masahiro Suzuki
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Shiori Yamakawa
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Syuzi Uno
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Ai Ishii
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Satoshi Yamazaki
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Rino Fukatsu
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Ryo Fujisawa
- Department of Biology, Faculty of Science, Kyushu University 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Toshiki Tsurimoto
- Department of Biology, Faculty of Science, Kyushu University 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hisao Masai
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, 4-6-1 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
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31
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Cipolla L, Maffia A, Bertoletti F, Sabbioneda S. The Regulation of DNA Damage Tolerance by Ubiquitin and Ubiquitin-Like Modifiers. Front Genet 2016; 7:105. [PMID: 27379156 PMCID: PMC4904029 DOI: 10.3389/fgene.2016.00105] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/25/2016] [Indexed: 11/13/2022] Open
Abstract
DNA replication is an extremely complex process that needs to be executed in a highly accurate manner in order to propagate the genome. This task requires the coordination of a number of enzymatic activities and it is fragile and prone to arrest after DNA damage. DNA damage tolerance provides a last line of defense that allows completion of DNA replication in the presence of an unrepaired template. One of such mechanisms is called post-replication repair (PRR) and it is used by the cells to bypass highly distorted templates caused by damaged bases. PRR is extremely important for the cellular life and performs the bypass of the damage both in an error-free and in an error-prone manner. In light of these two possible outcomes, PRR needs to be tightly controlled in order to prevent the accumulation of mutations leading ultimately to genome instability. Post-translational modifications of PRR proteins provide the framework for this regulation with ubiquitylation and SUMOylation playing a pivotal role in choosing which pathway to activate, thus controlling the different outcomes of damage bypass. The proliferating cell nuclear antigen (PCNA), the DNA clamp for replicative polymerases, plays a central role in the regulation of damage tolerance and its modification by ubiquitin, and SUMO controls both the error-free and error-prone branches of PRR. Furthermore, a significant number of polymerases are involved in the bypass of DNA damage possess domains that can bind post-translational modifications and they are themselves target for ubiquitylation. In this review, we will focus on how ubiquitin and ubiquitin-like modifications can regulate the DNA damage tolerance systems and how they control the recruitment of different proteins to the replication fork.
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Affiliation(s)
- Lina Cipolla
- Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche, Pavia Italia
| | - Antonio Maffia
- Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche, Pavia Italia
| | - Federica Bertoletti
- Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche, Pavia Italia
| | - Simone Sabbioneda
- Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche, Pavia Italia
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32
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A Timeless Link Between Circadian Patterns and Disease. Trends Mol Med 2016; 22:68-81. [DOI: 10.1016/j.molmed.2015.11.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 11/16/2015] [Accepted: 11/18/2015] [Indexed: 02/06/2023]
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33
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Sanjiv K, Hagenkort A, Calderón-Montaño JM, Koolmeister T, Reaper PM, Mortusewicz O, Jacques SA, Kuiper RV, Schultz N, Scobie M, Charlton PA, Pollard JR, Berglund UW, Altun M, Helleday T. Cancer-Specific Synthetic Lethality between ATR and CHK1 Kinase Activities. Cell Rep 2015; 14:298-309. [PMID: 26748709 PMCID: PMC4713868 DOI: 10.1016/j.celrep.2015.12.032] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 11/04/2015] [Accepted: 12/03/2015] [Indexed: 02/05/2023] Open
Abstract
ATR and CHK1 maintain cancer cell survival under replication stress and inhibitors of both kinases are currently undergoing clinical trials. As ATR activity is increased after CHK1 inhibition, we hypothesized that this may indicate an increased reliance on ATR for survival. Indeed, we observe that replication stress induced by the CHK1 inhibitor AZD7762 results in replication catastrophe and apoptosis, when combined with the ATR inhibitor VE-821 specifically in cancer cells. Combined treatment with ATR and CHK1 inhibitors leads to replication fork arrest, ssDNA accumulation, replication collapse, and synergistic cell death in cancer cells in vitro and in vivo. Inhibition of CDK reversed replication stress and synthetic lethality, demonstrating that regulation of origin firing by ATR and CHK1 explains the synthetic lethality. In conclusion, this study exemplifies cancer-specific synthetic lethality between two proteins in the same pathway and raises the prospect of combining ATR and CHK1 inhibitors as promising cancer therapy.
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Affiliation(s)
- Kumar Sanjiv
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Anna Hagenkort
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - José Manuel Calderón-Montaño
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Tobias Koolmeister
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Philip M Reaper
- Vertex Pharmaceuticals (Europe) Ltd., Abingdon, Oxfordshire OX14 4RW, UK
| | - Oliver Mortusewicz
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Sylvain A Jacques
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Raoul V Kuiper
- Laboratory Medicine, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Niklas Schultz
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Martin Scobie
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Peter A Charlton
- Vertex Pharmaceuticals (Europe) Ltd., Abingdon, Oxfordshire OX14 4RW, UK
| | - John R Pollard
- Vertex Pharmaceuticals (Europe) Ltd., Abingdon, Oxfordshire OX14 4RW, UK
| | - Ulrika Warpman Berglund
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Mikael Altun
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden
| | - Thomas Helleday
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 21 Stockholm, Sweden.
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Abstract
The DNA damage response (DDR) has been broadly defined as a complex network of cellular pathways that cooperate to sense and repair lesions in DNA. Multiple types of DNA damage, some natural DNA sequences, nucleotide pool deficiencies and collisions with transcription complexes can cause replication arrest to elicit the DDR. However, in practice, the term DDR as applied to eukaryotic/mammalian cells often refers more specifically to pathways involving the activation of the ATM (ataxia-telangiectasia mutated) and ATR (ATM-Rad3-related) kinases in response to double-strand breaks or arrested replication forks, respectively. Nevertheless, there are distinct responses to particular types of DNA damage that do not involve ATM or ATR. In addition, some of the aberrations that cause replication arrest and elicit the DDR cannot be categorized as direct DNA damage. These include nucleotide pool deficiencies, nucleotide sequences that can adopt non-canonical DNA structures, and collisions between replication forks and transcription complexes. The response to these aberrations can be called the genomic stress response (GSR), a term that is meant to encompass the sensing of all types of DNA aberrations together with the mechanisms involved in coping with them. In addition to fully functional cells, the consequences of processing genomic aberrations may include mutagenesis, genomic rearrangements and lethality.
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Affiliation(s)
- Philip C Hanawalt
- Department of Biology, Stanford University, Stanford, CA 94305-5020, USA.
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35
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Niimi A, Hopkins SR, Downs JA, Masutani C. The BAH domain of BAF180 is required for PCNA ubiquitination. Mutat Res 2015; 779:16-23. [PMID: 26117423 DOI: 10.1016/j.mrfmmm.2015.06.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 06/03/2015] [Accepted: 06/14/2015] [Indexed: 06/04/2023]
Abstract
Monoubiquitination of proliferating cell nuclear antigen (PCNA) is a critical regulator of post replication repair (PRR). The depletion of BAF180, a unique subunit of the PBAF chromatin remodeling complex in human cells results in reduced PCNA ubiquitination leading to less efficient fork progression following DNA damage, but little is known about the mechanism. Here, we report that the expression of exogenous BAF180 in cells promotes PCNA ubiquitination during S-phase after UV irradiation and it persists for many hours. No correlation was observed between the protein level of ubiquitin-specific protease 1 (USP1) and ubiquitinated PCNA in BAF180 expressing cells. Analysis of cells expressing BAF180 deletion mutants showed that the bromo-adjacent homology (BAH) domains are responsible for this effect. Surprisingly, a deletion construct encoding only the BAH domain region is able to increase the level of ubiquitinated PCNA, even though it is unable to be assembled into the PBAF complex. These results suggest that the ATPase-dependent chromatin remodeling activity of PBAF is not necessary, but instead the BAH domains are sufficient to promote PCNA ubiquitination.
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Affiliation(s)
- Atsuko Niimi
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Suzanna R Hopkins
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Jessica A Downs
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Chikahide Masutani
- Department of Genome Dynamics, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
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36
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Abstract
Replicative polymerases (pols) cannot accommodate damaged template bases, and these pols stall when such offenses are encountered during S phase. Rather than repairing the damaged base, replication past it may proceed via one of two DNA damage tolerance (DDT) pathways, allowing replicative DNA synthesis to resume. In translesion DNA synthesis (TLS), a specialized TLS pol is recruited to catalyze stable, yet often erroneous, nucleotide incorporation opposite damaged template bases. In template switching, the newly synthesized sister strand is used as a damage-free template to synthesize past the lesion. In eukaryotes, both pathways are regulated by the conjugation of ubiquitin to the PCNA sliding clamp by distinct E2/E3 pairs. Whereas monoubiquitination by Rad6/Rad18 mediates TLS, extension of this ubiquitin to a polyubiquitin chain by Ubc13-Mms2/Rad5 routes DDT to the template switching pathway. In this review, we focus on the monoubiquitination of PCNA by Rad6/Rad18 and summarize the current knowledge of how this process is regulated.
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Affiliation(s)
- Mark Hedglin
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802; ,
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37
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González Besteiro MA, Gottifredi V. The fork and the kinase: a DNA replication tale from a CHK1 perspective. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2014; 763:168-80. [PMID: 25795119 DOI: 10.1016/j.mrrev.2014.10.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Revised: 10/07/2014] [Accepted: 10/10/2014] [Indexed: 11/30/2022]
Abstract
Replication fork progression is being continuously hampered by exogenously introduced and naturally occurring DNA lesions and other physical obstacles. Checkpoint kinase 1 (Chk1) is activated at replication forks that encounter damaged DNA. Subsequently, Chk1 inhibits the initiation of new replication factories and stimulates the firing of dormant origins (those in the vicinity of stalled forks). Chk1 also avoids fork collapse into DSBs (double strand breaks) and promotes fork elongation. At the molecular level, the current model considers stalled forks as the site of Chk1 activation and the nucleoplasm as the location where Chk1 phosphorylates target proteins. This model certainly serves to explain how Chk1 modulates origin firing, but how Chk1 controls the fate of stalled forks is less clear. Interestingly, recent reports demonstrating that Chk1 phosphorylates chromatin-bound proteins and even holds kinase-independent functions might shed light on how Chk1 contributes to the elongation of damaged DNA. Indeed, such findings have unveiled a puzzling connection between Chk1 and DNA lesion bypass, which might be central to promoting fork elongation and checkpoint attenuation. In summary, Chk1 is a multifaceted and versatile signaling factor that acts at ongoing forks and replication origins to determine the extent and quality of the cellular response to replication stress.
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Affiliation(s)
- Marina A González Besteiro
- Cell Cycle and Genomic Stability Laboratory, Fundación Instituto Leloir, CONICET, Buenos Aires, Argentina
| | - Vanesa Gottifredi
- Cell Cycle and Genomic Stability Laboratory, Fundación Instituto Leloir, CONICET, Buenos Aires, Argentina.
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38
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Han J, Liu T, Huen MSY, Hu L, Chen Z, Huang J. SIVA1 directs the E3 ubiquitin ligase RAD18 for PCNA monoubiquitination. ACTA ACUST UNITED AC 2014; 205:811-27. [PMID: 24958773 PMCID: PMC4068132 DOI: 10.1083/jcb.201311007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Translesion DNA synthesis (TLS) is a universal DNA damage tolerance mechanism conserved from yeast to mammals. A key event in the regulation of TLS is the monoubiquitination of proliferating cell nuclear antigen (PCNA). Extensive evidence indicates that the RAD6-RAD18 ubiquitin-conjugating/ligase complex specifically monoubiquitinates PCNA and regulates TLS repair. However, the mechanism by which the RAD6-RAD18 complex is targeted to PCNA has remained elusive. In this study, we used an affinity purification approach to isolate the PCNA-containing complex and have identified SIVA1 as a critical regulator of PCNA monoubiquitination. We show that SIVA1 constitutively interacts with PCNA via a highly conserved PCNA-interacting peptide motif. Knockdown of SIVA1 compromised RAD18-dependent PCNA monoubiquitination and Polη focus formation, leading to elevated ultraviolet sensitivity and mutation. Furthermore, we demonstrate that SIVA1 interacts with RAD18 and serves as a molecular bridge between RAD18 and PCNA, thus targeting the E3 ligase activity of RAD18 onto PCNA. Collectively, our results provide evidence that the RAD18 E3 ligase requires an accessory protein for binding to its substrate PCNA.
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Affiliation(s)
- Jinhua Han
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Ting Liu
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Michael S Y Huen
- Department of Anatomy and Center for Cancer Research, The University of Hong Kong, Hong Kong, China Department of Anatomy and Center for Cancer Research, The University of Hong Kong, Hong Kong, China
| | - Lin Hu
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Zhiqiu Chen
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jun Huang
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
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39
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Yan S, Sorrell M, Berman Z. Functional interplay between ATM/ATR-mediated DNA damage response and DNA repair pathways in oxidative stress. Cell Mol Life Sci 2014; 71:3951-67. [PMID: 24947324 DOI: 10.1007/s00018-014-1666-4] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 06/03/2014] [Accepted: 06/05/2014] [Indexed: 02/07/2023]
Abstract
To maintain genome stability, cells have evolved various DNA repair pathways to deal with oxidative DNA damage. DNA damage response (DDR) pathways, including ATM-Chk2 and ATR-Chk1 checkpoints, are also activated in oxidative stress to coordinate DNA repair, cell cycle progression, transcription, apoptosis, and senescence. Several studies demonstrate that DDR pathways can regulate DNA repair pathways. On the other hand, accumulating evidence suggests that DNA repair pathways may modulate DDR pathway activation as well. In this review, we summarize our current understanding of how various DNA repair and DDR pathways are activated in response to oxidative DNA damage primarily from studies in eukaryotes. In particular, we analyze the functional interplay between DNA repair and DDR pathways in oxidative stress. A better understanding of cellular response to oxidative stress may provide novel avenues of treating human diseases, such as cancer and neurodegenerative disorders.
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Affiliation(s)
- Shan Yan
- Department of Biological Sciences, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC, 28223, USA,
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40
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Leman AR, Noguchi E. The replication fork: understanding the eukaryotic replication machinery and the challenges to genome duplication. Genes (Basel) 2014; 4:1-32. [PMID: 23599899 PMCID: PMC3627427 DOI: 10.3390/genes4010001] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Eukaryotic cells must accurately and efficiently duplicate their genomes during each round of the cell cycle. Multiple linear chromosomes, an abundance of regulatory elements, and chromosome packaging are all challenges that the eukaryotic DNA replication machinery must successfully overcome. The replication machinery, the “replisome” complex, is composed of many specialized proteins with functions in supporting replication by DNA polymerases. Efficient replisome progression relies on tight coordination between the various factors of the replisome. Further, replisome progression must occur on less than ideal templates at various genomic loci. Here, we describe the functions of the major replisome components, as well as some of the obstacles to efficient DNA replication that the replisome confronts. Together, this review summarizes current understanding of the vastly complicated task of replicating eukaryotic DNA.
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Affiliation(s)
- Adam R. Leman
- Authors to whom correspondence should be addressed; E-Mails: (A.R.L.); (E.N.); Tel.: +1-215-762-4825 (E.N.); Fax: +1-215-762-4452 (E.N.)
| | - Eishi Noguchi
- Authors to whom correspondence should be addressed; E-Mails: (A.R.L.); (E.N.); Tel.: +1-215-762-4825 (E.N.); Fax: +1-215-762-4452 (E.N.)
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41
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Lin YF, Shih HY, Shang Z, Matsunaga S, Chen BP. DNA-PKcs is required to maintain stability of Chk1 and Claspin for optimal replication stress response. Nucleic Acids Res 2014; 42:4463-73. [PMID: 24500207 PMCID: PMC3985680 DOI: 10.1093/nar/gku116] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The ataxia telangiectasia mutated and Rad3-related (ATR)-checkpoint kinase 1 (Chk1) axis is the major signaling pathway activated in response to replication stress and is essential for the intra-S checkpoint. ATR phosphorylates and activates a number of molecules to coordinate cell cycle progression. Chk1 is the major effector downstream from ATR and plays a critical role in intra-S checkpoint on replication stress. Activation of Chk1 kinase also requires its association with Claspin, an adaptor protein essential for Chk1 protein stability, recruitment and ATR-dependent Chk1 phosphorylation. We have previously reported that, on replication stress, the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is rapidly phosphorylated by ATR at the stalled replication forks and is required for cellular resistance to replication stresses although the impact of DNA-PKcs onto the ATR signaling pathway remains elusive. Here we report that ATR-dependent Chk1 phosphorylation and Chk1 signaling are compromised in the absence of DNA-PKcs. Our investigation reveals that DNA-PKcs is required to maintain Chk1–Claspin complex stability and transcriptional regulation of Claspin expression. The impaired Chk1 activity results in a defective intra-S checkpoint response in DNA-PKcs–deficient cells. Taken together, these results suggest that DNA-PKcs, in addition to its direct role in DNA damage repair, facilitates ATR-Chk1 signaling pathway in response to replication stress.
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Affiliation(s)
- Yu-Fen Lin
- Division of Molecular Radiation Biology, Department of Radiation Oncology, University of Texas, Southwestern Medical Center at Dallas, Dallas, TX 75390, USA and Division of Molecular Pharmacology, Department of Pathophysiological and Therapeutic Science, Tottori University, Japan
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42
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Leman AR, Noguchi E. Chromatin immunoprecipitation to investigate origin association of replication factors in mammalian cells. Methods Mol Biol 2014; 1170:539-47. [PMID: 24906335 DOI: 10.1007/978-1-4939-0888-2_30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A variety of DNA-binding proteins regulate DNA transactions including DNA replication and DNA damage response. To initiate DNA replication in S phase of the cell cycle, numerous replication proteins must be recruited to the replication origin in order to unwind and synthesize DNA. Some replication factors stay at the origin, while replisome components move with the replication fork. When the replisome encounters DNA damage or other issues during DNA replication, the replication fork stalls and accumulates single-stranded DNA that triggers the ATR-dependent replication checkpoint, in order to slow down S phase and arrest the cell cycle at the G2-M transition. It is also possible that replication forks collapse, leading to double-strand breaks that recruit various DNA damage response proteins to activate cell cycle checkpoints and DNA repair pathways. Therefore, defining the localization of DNA transaction factors during the cell cycle should provide important insights into mechanistic understanding of DNA replication and its related processes. In this chapter, we describe a chromatin immunoprecipitation method to locate replisome components at replication origins in human cells.
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Affiliation(s)
- Adam R Leman
- Department of Biology, Duke University, Durham, NC, USA
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43
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Abstract
DNA damage is one of many possible perturbations that challenge the mechanisms that preserve genetic stability during the copying of the eukaryotic genome in S phase. This short review provides, in the first part, a general introduction to the topic and an overview of checkpoint responses. In the second part, the mechanisms of error-free tolerance in response to fork-arresting DNA damage will be discussed in some detail.
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Affiliation(s)
- Nimrat Chatterjee
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
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44
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Gallego-Sánchez A, Ufano S, Andrés S, Bueno A. Analysis of the tolerance to DNA alkylating damage in MEC1 and RAD53 checkpoint mutants of Saccharomyces cerevisiae. PLoS One 2013; 8:e81108. [PMID: 24260543 PMCID: PMC3834268 DOI: 10.1371/journal.pone.0081108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 10/18/2013] [Indexed: 01/04/2023] Open
Abstract
Checkpoint response, tolerance and repair are three major pathways that eukaryotic cells evolved independently to maintain genome stability and integrity. Here, we studied the sensitivity to DNA damage in checkpoint-deficient budding yeast cells and found that checkpoint kinases Mec1 and Rad53 may modulate the balance between error-free and error-prone branches of the tolerance pathway. We have consistently observed that mutation of the RAD53 counterbalances error-free and error-prone branches upon exposure of cells to DNA damage induced either by MMS alkylation or by UV-radiation. We have also found that the potential Mec1/Rad53 balance modulation is independent from Rad6/Rad18-mediated PCNA ubiquitylation, as mec1Δ or rad53Δ mutants show no defects in the modification of the sliding clamp, therefore, we infer that it is likely exerted by acting on TLS polymerases and/or template switching targets.
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Affiliation(s)
- Alfonso Gallego-Sánchez
- Instituto de Biología Molecular y Celular del Cáncer, Departamento de Microbiología y Genética, Universidad de Salamanca/CSIC, Salamanca, Spain
| | - Sandra Ufano
- Instituto de Biología Molecular y Celular del Cáncer, Departamento de Microbiología y Genética, Universidad de Salamanca/CSIC, Salamanca, Spain
| | - Sonia Andrés
- Instituto de Biología Molecular y Celular del Cáncer, Departamento de Microbiología y Genética, Universidad de Salamanca/CSIC, Salamanca, Spain
| | - Avelino Bueno
- Instituto de Biología Molecular y Celular del Cáncer, Departamento de Microbiología y Genética, Universidad de Salamanca/CSIC, Salamanca, Spain
- * E-mail:
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45
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Chaudhuri L, Vincelette ND, Koh BD, Naylor RM, Flatten KS, Peterson KL, McNally A, Gojo I, Karp JE, Mesa RA, Sproat LO, Bogenberger JM, Kaufmann SH, Tibes R. CHK1 and WEE1 inhibition combine synergistically to enhance therapeutic efficacy in acute myeloid leukemia ex vivo. Haematologica 2013; 99:688-96. [PMID: 24179152 DOI: 10.3324/haematol.2013.093187] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Novel combinations targeting new molecular vulnerabilities are needed to improve the outcome of patients with acute myeloid leukemia. We recently identified WEE1 kinase as a novel target in leukemias. To identify genes that are synthetically lethal with WEE1 inhibition, we performed a short interfering RNA screen directed against cell cycle and DNA repair genes during concurrent treatment with the WEE1 inhibitor MK1775. CHK1 and ATR, genes encoding two replication checkpoint kinases, were among the genes whose silencing enhanced the effects of WEE1 inhibition most, whereas CDK2 short interfering RNA antagonized MK1775 effects. Building on this observation, we examined the impact of combining MK1775 with selective small molecule inhibitors of CHK1, ATR and cyclin-dependent kinases. The CHK1 inhibitor MK8776 sensitized acute myeloid leukemia cell lines and primary leukemia specimens to MK1775 ex vivo, whereas smaller effects were observed with the MK1775/MK8776 combination in normal myeloid progenitors. The ATR inhibitor VE-821 likewise enhanced the antiproliferative effects of MK1775, whereas the cyclin-dependent kinase inhibitor roscovitine antagonized MK1775. Further studies showed that MK8776 enhanced MK1775-mediated activation of the ATR/CHK1 pathway in acute leukemia cell lines and ex vivo. These results indicate that combined cell cycle checkpoint interference with MK1775/MK8776 warrants further investigation as a potential treatment for acute myeloid leukemia.
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46
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Sproul CD, Rao S, Ibrahim JG, Kaufmann WK, Cordeiro-Stone M. Is activation of the intra-S checkpoint in human fibroblasts an important factor in protection against UV-induced mutagenesis? Cell Cycle 2013; 12:3555-63. [PMID: 24091629 DOI: 10.4161/cc.26590] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The ATR/CHK1-dependent intra-S checkpoint inhibits replicon initiation and replication fork progression in response to DNA damage caused by UV (UV) radiation. It has been proposed that this signaling cascade protects against UV-induced mutations by reducing the probability that damaged DNA will be replicated before it can be repaired. Normal human fibroblasts (NHF) were depleted of ATR or CHK1, or treated with the CHK1 kinase inhibitor TCS2312, and the UV-induced mutation frequency at the HPRT locus was measured. Despite clear evidence of S-phase checkpoint abrogation, neither ATR/CHK1 depletion nor CHK1 inhibition caused an increase in the UV-induced HPRT mutation frequency. These results question the premise that the UV-induced intra-S checkpoint plays a prominent role in protecting against UV-induced mutagenesis.
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Affiliation(s)
- Christopher D Sproul
- Curriculum in Toxicology; University of North Carolina-Chapel Hill; Chapel Hill, NC USA
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47
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BRCA1 promotes the ubiquitination of PCNA and recruitment of translesion polymerases in response to replication blockade. Proc Natl Acad Sci U S A 2013; 110:13558-63. [PMID: 23901102 DOI: 10.1073/pnas.1306534110] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Breast cancer gene 1 (BRCA1) deficient cells not only are hypersensitive to double-strand breaks but also are hypersensitive to UV irradiation and other agents that cause replication blockade; however, the molecular mechanisms behind these latter sensitivities are largely unknown. Here, we report that BRCA1 promotes cell survival by directly regulating the DNA damage tolerance pathway in response to agents that create cross-links in DNA. We show that BRCA1 not only promotes efficient mono- and polyubiquitination of proliferating cell nuclear antigen (PCNA) by regulating the recruitment of replication protein A, Rad18, and helicase-like transcription factor to chromatin but also directly recruits translesion polymerases, such as Polymerase eta and Rev1, to the lesions through protein-protein interactions. Our data suggest that BRCA1 plays a critical role in promoting translesion DNA synthesis as well as DNA template switching.
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48
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Mason JM, Das I, Arlt M, Patel N, Kraftson S, Glover TW, Sekiguchi JM. The SNM1B/APOLLO DNA nuclease functions in resolution of replication stress and maintenance of common fragile site stability. Hum Mol Genet 2013; 22:4901-13. [PMID: 23863462 DOI: 10.1093/hmg/ddt340] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
SNM1B/Apollo is a DNA nuclease that has important functions in telomere maintenance and repair of DNA interstrand crosslinks (ICLs) within the Fanconi anemia (FA) pathway. SNM1B is required for efficient localization of key repair proteins, such as the FA protein, FANCD2, to sites of ICL damage and functions epistatically to FANCD2 in cellular survival to ICLs and homology-directed repair. The FA pathway is also activated in response to replication fork stalling. Here, we sought to determine the importance of SNM1B in cellular responses to stalled forks in the absence of a blocking lesion, such as ICLs. We found that depletion of SNM1B results in hypersensitivity to aphidicolin, a DNA polymerase inhibitor that causes replication stress. We observed that the SNM1B nuclease is required for efficient localization of the DNA repair proteins, FANCD2 and BRCA1, to subnuclear foci upon aphidicolin treatment, thereby indicating SNM1B facilitates direct repair of stalled forks. Consistent with a role for SNM1B subsequent to recognition of the lesion, we found that SNM1B is dispensable for upstream events, including activation of ATR-dependent signaling and localization of RPA, γH2AX and the MRE11/RAD50/NBS1 complex to aphidicolin-induced foci. We determined that a major consequence of SNM1B depletion is a marked increase in spontaneous and aphidicolin-induced chromosomal gaps and breaks, including breakage at common fragile sites. Thus, this study provides evidence that SNM1B functions in resolving replication stress and preventing accumulation of genomic damage.
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49
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Mailand N, Gibbs-Seymour I, Bekker-Jensen S. Regulation of PCNA-protein interactions for genome stability. Nat Rev Mol Cell Biol 2013; 14:269-82. [PMID: 23594953 DOI: 10.1038/nrm3562] [Citation(s) in RCA: 265] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Proliferating cell nuclear antigen (PCNA) has a central role in promoting faithful DNA replication, providing a molecular platform that facilitates the myriad protein-protein and protein-DNA interactions that occur at the replication fork. Numerous PCNA-associated proteins compete for binding to a common surface on PCNA; hence these interactions need to be tightly regulated and coordinated to ensure proper chromosome replication and integrity. Control of PCNA-protein interactions is multilayered and involves post-translational modifications, in particular ubiquitylation, accessory factors and regulated degradation of PCNA-associated proteins. This regulatory framework allows cells to maintain a fine-tuned balance between replication fidelity and processivity in response to DNA damage.
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Affiliation(s)
- Niels Mailand
- Ubiquitin Signaling Group, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
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50
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Patil M, Pabla N, Dong Z. Checkpoint kinase 1 in DNA damage response and cell cycle regulation. Cell Mol Life Sci 2013; 70:4009-21. [PMID: 23508805 DOI: 10.1007/s00018-013-1307-3] [Citation(s) in RCA: 190] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 01/28/2013] [Accepted: 02/18/2013] [Indexed: 12/19/2022]
Abstract
Originally identified as a mediator of DNA damage response (DDR), checkpoint kinase 1 (Chk1) has a broader role in checkpoint activation in DDR and normal cell cycle regulation. Chk1 activation involves phosphorylation at conserved sites. However, recent work has identified a splice variant of Chk1, which may regulate Chk1 in both DDR and normal cell cycle via molecular interaction. Upon activation, Chk1 phosphorylates a variety of substrate proteins, resulting in the activation of DNA damage checkpoints, cell cycle arrest, DNA repair, and/or cell death. Chk1 and its related signaling may be an effective therapeutic target in diseases such as cancer.
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Affiliation(s)
- Mallikarjun Patil
- Department of Cellular Biology and Anatomy, Georgia Regents University and Charlie Norwood VA Medical Center, 1459 Laney Walker Blvd., Augusta, GA, 30912, USA
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