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Willman GH, Xu H, Zeigler TM, McIntosh MT, Bhaduri-McIntosh S. Polymerase theta is a synthetic lethal target for killing Epstein-Barr virus lymphomas. J Virol 2024:e0057224. [PMID: 38860782 DOI: 10.1128/jvi.00572-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/27/2024] [Indexed: 06/12/2024] Open
Abstract
Treatment options for Epstein-Barr virus (EBV)-cancers are limited, underscoring the need for new therapeutic approaches. We have previously shown that EBV-transformed cells and cancers lack homologous recombination (HR) repair, a prominent error-free pathway that repairs double-stranded DNA breaks; instead, EBV-transformed cells demonstrate genome-wide scars of the error-prone microhomology-mediated end joining (MMEJ) repair pathway. This suggests that EBV-cancers are vulnerable to synthetic lethal therapeutic approaches that target MMEJ repair. Indeed, we have previously found that targeting PARP, an enzyme that contributes to MMEJ, results in the death of EBV-lymphoma cells. With the emergence of clinical resistance to PARP inhibitors and the recent discovery of inhibitors of Polymerase theta (POLθ), the polymerase essential for MMEJ, we investigated the role of POLθ in EBV-lymphoma cells. We report that EBV-transformed cell lines, EBV-lymphoma cell lines, and EBV-lymphomas in AIDS patients demonstrate greater abundance of POLθ, driven by the EBV protein EBNA1, compared to EBV-uninfected primary lymphocytes and EBV-negative lymphomas from AIDS patients (a group that also abundantly expresses POLθ). We also find POLθ enriched at cellular DNA replication forks and exposure to the POLθ inhibitor Novobiocin impedes replication fork progress, impairs MMEJ-mediated repair of DNA double-stranded breaks, and kills EBV-lymphoma cells. Notably, cell killing is not due to Novobiocin-induced activation of the lytic/replicative phase of EBV. These findings support a role for POLθ not just in DNA repair but also DNA replication and as a therapeutic target in EBV-lymphomas and potentially other EBV-cancers as EBNA1 is expressed in all EBV-cancers.IMPORTANCEEpstein-Barr virus (EBV) contributes to ~2% of the global cancer burden. With a recent estimate of >200,000 deaths a year, identifying molecular vulnerabilities will be key to the management of these frequently aggressive and treatment-resistant cancers. Building on our earlier work demonstrating reliance of EBV-cancers on microhomology-mediated end-joining repair, we now report that EBV lymphomas and transformed B cell lines abundantly express the MMEJ enzyme POLθ that likely protects cellular replication forks and repairs replication-related cellular DNA breaks. Importantly also, we show that a newly identified POLθ inhibitor kills EBV-cancer cells, revealing a novel strategy to block DNA replication and repair of these aggressive cancers.
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Affiliation(s)
- Griffin H Willman
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, Florida, USA
| | - Huanzhou Xu
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, Florida, USA
| | - Travis M Zeigler
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, Florida, USA
| | - Michael T McIntosh
- Child Health Research Institute, Department of Pediatrics, University of Florida, Gainesville, Florida, USA
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, USA
| | - Sumita Bhaduri-McIntosh
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, Florida, USA
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, USA
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2
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Thomas C, Avalos-Irving L, Victorino J, Green S, Andrews M, Rodrigues N, Ebirim S, Mudd A, Towle-Weicksel JB. Melanoma-derived DNA polymerase theta variants exhibit altered DNA polymerase activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.566933. [PMID: 38014040 PMCID: PMC10680777 DOI: 10.1101/2023.11.14.566933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
DNA Polymerase θ (Pol θ or POLQ) is primarily involved in repairing double-stranded breaks in DNA through the alternative pathway known as microhomology-mediated end joining (MMEJ) or theta-mediated end joining (TMEJ). Unlike other DNA repair polymerases, Pol θ is thought to be highly error prone, yet critical for cell survival. We have identified several mutations in the POLQ gene from human melanoma tumors. Through biochemical analysis, we have demonstrated that all three cancer-associated variants experienced altered DNA polymerase activity including a propensity for incorrect nucleotide selection and reduced polymerization rates compared to WT Pol θ. Moreover, the variants are 30 fold less efficient at incorporating a nucleotide during repair and up to 70 fold less accurate at selecting the correct nucleotide opposite a templating base. Taken together, this suggests that aberrant Pol θ has reduced DNA repair capabilities and may also contribute to increased mutagenesis. While this may be beneficial to normal cell survival, the variants were identified in established tumors suggesting that cancer cells may use this promiscuous polymerase to its advantage to promote metastasis and drug resistance.
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3
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Nieminuszczy J, Martin PR, Broderick R, Krwawicz J, Kanellou A, Mocanu C, Bousgouni V, Smith C, Wen KK, Woodward B, Bakal C, Shackley F, Aguilera A, Stewart G, Vyas Y, Niedzwiedz W. Actin nucleators safeguard replication forks by limiting nascent strand degradation. Nucleic Acids Res 2023; 51:6337-6354. [PMID: 37224534 PMCID: PMC10325910 DOI: 10.1093/nar/gkad369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 04/17/2023] [Accepted: 05/11/2023] [Indexed: 05/26/2023] Open
Abstract
Accurate genome replication is essential for all life and a key mechanism of disease prevention, underpinned by the ability of cells to respond to replicative stress (RS) and protect replication forks. These responses rely on the formation of Replication Protein A (RPA)-single stranded (ss) DNA complexes, yet this process remains largely uncharacterized. Here, we establish that actin nucleation-promoting factors (NPFs) associate with replication forks, promote efficient DNA replication and facilitate association of RPA with ssDNA at sites of RS. Accordingly, their loss leads to deprotection of ssDNA at perturbed forks, impaired ATR activation, global replication defects and fork collapse. Supplying an excess of RPA restores RPA foci formation and fork protection, suggesting a chaperoning role for actin nucleators (ANs) (i.e. Arp2/3, DIAPH1) and NPFs (i.e, WASp, N-WASp) in regulating RPA availability upon RS. We also discover that β-actin interacts with RPA directly in vitro, and in vivo a hyper-depolymerizing β-actin mutant displays a heightened association with RPA and the same dysfunctional replication phenotypes as loss of ANs/NPFs, which contrasts with the phenotype of a hyper-polymerizing β-actin mutant. Thus, we identify components of actin polymerization pathways that are essential for preventing ectopic nucleolytic degradation of perturbed forks by modulating RPA activity.
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Affiliation(s)
- Jadwiga Nieminuszczy
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Peter R Martin
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Ronan Broderick
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Joanna Krwawicz
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Alexandra Kanellou
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Camelia Mocanu
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Vicky Bousgouni
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Charlotte Smith
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Kuo-Kuang Wen
- Department of Pediatrics, Division of Pediatric Hematology-Oncology, Penn State College of Medicine, Penn State Health Children's Hospital, Hershey, PA 17033, USA
| | - Beth L Woodward
- Genome Stability and Human Disease Laboratory, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Chris Bakal
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
| | - Fiona Shackley
- Paediatric Immunology, Allergy and Infectious Diseases, Sheffield Children's Hospital NHS Foundation Trust, Sheffield, UK
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Grant S Stewart
- Genome Stability and Human Disease Laboratory, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Yatin M Vyas
- Department of Pediatrics, Division of Pediatric Hematology-Oncology, Penn State College of Medicine, Penn State Health Children's Hospital, Hershey, PA 17033, USA
| | - Wojciech Niedzwiedz
- Division of Cancer Biology, The Institute of Cancer Research, London SW3 6JB, UK
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4
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Nieminuszczy J, Martin PR, Broderick R, Krwawicz J, Kanellou A, Mocanu C, Bousgouni V, Smith C, Wen KK, Woodward BL, Bakal C, Shackley F, Aguilera A, Stewart GS, Vyas YM, Niedzwiedz W. Actin nucleators safeguard replication forks by limiting nascent strand degradation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.12.523639. [PMID: 36711944 PMCID: PMC9882250 DOI: 10.1101/2023.01.12.523639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Accurate genome replication is essential for all life and a key mechanism of disease prevention, underpinned by the ability of cells to respond to replicative stress (RS) and protect replication forks. These responses rely on the formation of Replication Protein A (RPA)-single stranded (ss) DNA complexes, yet this process remains largely uncharacterized. Here we establish that actin nucleation-promoting factors (NPFs) associate with replication forks, promote efficient DNA replication and facilitate association of RPA with ssDNA at sites of RS. Accordingly, their loss leads to deprotection of ssDNA at perturbed forks, impaired ATR activation, global replication defects and fork collapse. Supplying an excess of RPA restores RPA foci formation and fork protection, suggesting a chaperoning role for actin nucleators (ANs) (i.e., Arp2/3, DIAPH1) and NPFs (i.e, WASp, N-WASp) in regulating RPA availability upon RS. We also discover that β-actin interacts with RPA directly in vitro , and in vivo a hyper-depolymerizing β-actin mutant displays a heightened association with RPA and the same dysfunctional replication phenotypes as loss of ANs/NPFs, which contrasts with the phenotype of a hyper-polymerizing β-actin mutant. Thus, we identify components of actin polymerization pathways that are essential for preventing ectopic nucleolytic degradation of perturbed forks by modulating RPA activity.
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Affiliation(s)
| | - Peter R. Martin
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Ronan Broderick
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Joanna Krwawicz
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | | | - Camelia Mocanu
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Vicky Bousgouni
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Charlotte Smith
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Kuo-Kuang Wen
- Department of Pediatrics, Division of Pediatric Hematology-Oncology, PennState College of Medicine, PennState Health Children’s Hospital, Hershey, Pennsylvania 17033, USA
| | - Beth L. Woodward
- Genome Stability and Human Disease Laboratory, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Chris Bakal
- Cancer Biology, The Institute of Cancer Research, London, SW3 6JB, UK
| | - Fiona Shackley
- Paediatric Immunology, Allergy and Infectious Diseases, Sheffield Children's Hospital NHS Foundation Trust, Sheffield, UK
| | - Andres Aguilera
- Centro Andaluz de Biologia Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC-Universidad Pablo de Olavide, Seville, Spain
| | - Grant S. Stewart
- Genome Stability and Human Disease Laboratory, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Yatin M. Vyas
- Department of Pediatrics, Division of Pediatric Hematology-Oncology, PennState College of Medicine, PennState Health Children’s Hospital, Hershey, Pennsylvania 17033, USA
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5
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RAD51 paralogs: Expanding roles in replication stress responses and repair. Curr Opin Pharmacol 2022; 67:102313. [PMID: 36343481 DOI: 10.1016/j.coph.2022.102313] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 09/26/2022] [Accepted: 09/29/2022] [Indexed: 11/06/2022]
Abstract
Mammalian RAD51 paralogs are essential for cell survival and are critical for RAD51-mediated repair of DNA double-strand breaks (DSBs) by homologous recombination (HR). However, the molecular mechanism by which RAD51 paralogs participate in HR is largely unclear. Germline mutations in RAD51 paralogs are associated with breast and ovarian cancers and Fanconi anemia-like disorder, underscoring the crucial roles of RAD51 paralogs in genome maintenance and tumor suppression. Despite their discovery over three decades ago, the essential functions of RAD51 paralogs in cell survival and genome stability remain obscure. Recent studies unravel DSB repair independent functions of RAD51 paralogs in replication stress responses. Here, we highlight the recent findings that uncovered the novel functions of RAD51 paralogs in replication fork progression, its stability, and restart and discuss RAD51 paralogs as a potential therapeutic target for cancer treatment.
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6
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Ding K, He Y, Wei J, Fu S, Wang J, Chen Z, Zhang H, Qu Y, Liang K, Gong X, Qiu L, Chen D, Xiao B, Du H. A score of DNA damage repair pathway with the predictive ability for chemotherapy and immunotherapy is strongly associated with immune signaling pathway in pan-cancer. Front Immunol 2022; 13:943090. [PMID: 36081518 PMCID: PMC9445361 DOI: 10.3389/fimmu.2022.943090] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/09/2022] [Indexed: 11/29/2022] Open
Abstract
DNA damage repair (DDR) is critical in maintaining normal cellular function and genome integrity and is associated with cancer risk, progression, and therapeutic response. However, there is still a lack of a thorough understanding of the effects of DDR genes’ expression level in cancer progression and therapeutic resistance. Therefore, we defined a tumor-related DDR score (TR-DDR score), utilizing the expression levels of 20 genes, to quantify the tumor signature of DNA damage repair pathways in tumors and explore the possible function and mechanism for the score among different cancers. The TR-DDR score has remarkably predictive power for tumor tissues. It is a more accurate indicator for the response of chemotherapy or immunotherapy combined with the tumor-infiltrating lymphocyte (TIL) and G2M checkpoint score than the pre-existing predictors (CD8 or PD-L1). This study points out that the TR-DDR score generally has positive correlations with patients of advanced-stage, genome-instability, and cell proliferation signature, while negative correlations with inflammatory response, apoptosis, and p53 pathway signature. In the context of tumor immune response, the TR-DDR score strongly positively correlates with the number of T cells (CD4+ activated memory cells, CD8+ cells, T regs, Tfh) and macrophages M1 polarization. In addition, by difference analysis and correlation analysis, COL2A1, MAGEA4, FCRL4, and ZIC1 are screened out as the potential modulating factors for the TR-DDR score. In summary, we light on a new biomarker for DNA damage repair pathways and explore its possible mechanism to guide therapeutic strategies and drug response prediction.
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Affiliation(s)
- Ke Ding
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Youhua He
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Jinfen Wei
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Shuying Fu
- College of Life Science, Zhaoqing University, Zhaoqing, China
| | - Jiajian Wang
- Clinical Laboratory Department of Longgang District People’s Hospital of Shenzhen & The Second Affiliated Hospital of the Chinese University of Hong Kong, Shenzhen, China
| | - Zixi Chen
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Haibo Zhang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Yimo Qu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Keying Liang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Xiaocheng Gong
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Li Qiu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Dong Chen
- Fangrui Institute of Innovative Drugs, South China University of Technology, Guangzhou, China
| | - Botao Xiao
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
- *Correspondence: Botao Xiao, ; Hongli Du,
| | - Hongli Du
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
- *Correspondence: Botao Xiao, ; Hongli Du,
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7
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Brown JAL, Bourke E, Hancock WW, Richard DJ. Editorial: Mechanisms guarding the genome. Front Cell Dev Biol 2022; 10:974545. [PMID: 36046336 PMCID: PMC9421295 DOI: 10.3389/fcell.2022.974545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 07/05/2022] [Indexed: 11/23/2022] Open
Affiliation(s)
- James A. L. Brown
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
- Limerick Digital Cancer Research Centre, HRI, ULCaN, University of Limerick, Limerick, Ireland
- *Correspondence: James A. L. Brown,
| | - E Bourke
- Lambe Institute for Translational Research, Discipline of Pathology, Centre for Chromosome Biology, National University of Ireland, Galway, Ireland
| | - W. W Hancock
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - D. J Richard
- Cancer and Ageing Research Program, School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
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8
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Chen K, Yang A, Carbone DP, Kanu N, Liu K, Wang R, Nie Y, Shen H, Bai J, Wu L, Li H, Shi Y, Mok T, Yu J, Yang F, Wu S, Jamal-Hanjani M, Wang J. Spatiotemporal genomic analysis reveals distinct molecular features in recurrent stage I non-small cell lung cancers. Cell Rep 2022; 40:111047. [PMID: 35830809 DOI: 10.1016/j.celrep.2022.111047] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 04/26/2022] [Accepted: 06/13/2022] [Indexed: 11/21/2022] Open
Abstract
Stage I non-small cell lung cancer (NSCLC) presents diverse outcomes. To identify molecular features leading to tumor recurrence in early-stage NSCLC, we perform multiregional whole-exome sequencing (WES), RNA sequencing, and plasma-targeted circulating tumor DNA (ctDNA) detection analysis between recurrent and recurrent-free stage I NSCLC patients (CHN-P cohort) who had undergone R0 resection with a median 5-year follow-up time. Integrated analysis indicates that the multidimensional clinical and genomic model can stratify the prognosis of stage I NSCLC in both CHN-P and EUR-T cohorts and correlates with positive pre-surgical deep next generation sequencing (NGS) ctDNA detection. Increased genomic instability related to DNA interstrand crosslinks and double-strand break repair processes is significantly associated with early tumor relapse. This study reveals important molecular insights into stage I NSCLC and may inform clinical postoperative treatment and follow-up strategies.
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Affiliation(s)
- Kezhong Chen
- Thoracic Oncology Institute and Department of Thoracic Surgery, Peking University People's Hospital, Beijing 100044, China; Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Airong Yang
- Berry Oncology Corporation, Beijing 100102, China
| | | | - Nnennaya Kanu
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
| | - Ke Liu
- Berry Oncology Corporation, Beijing 100102, China
| | - Ruiru Wang
- Berry Oncology Corporation, Beijing 100102, China
| | - Yuntao Nie
- Thoracic Oncology Institute and Department of Thoracic Surgery, Peking University People's Hospital, Beijing 100044, China
| | - Haifeng Shen
- Thoracic Oncology Institute and Department of Thoracic Surgery, Peking University People's Hospital, Beijing 100044, China
| | - Jian Bai
- Berry Oncology Corporation, Beijing 100102, China
| | - Lin Wu
- Berry Oncology Corporation, Beijing 100102, China
| | - Hui Li
- Berry Oncology Corporation, Beijing 100102, China
| | - Yanbin Shi
- Berry Oncology Corporation, Beijing 100102, China
| | - Tony Mok
- Department of Clinical Oncology, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Jun Yu
- University of Chinese Academy of Sciences, Beijing 100101, China
| | - Fan Yang
- Thoracic Oncology Institute and Department of Thoracic Surgery, Peking University People's Hospital, Beijing 100044, China.
| | - Shuangxiu Wu
- Berry Oncology Corporation, Beijing 100102, China.
| | - Mariam Jamal-Hanjani
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK; Cancer Metastasis Laboratory, University College London Cancer Institute, London, UK; Department of Medical Oncology, University College London Hospitals, London, UK.
| | - Jun Wang
- Thoracic Oncology Institute and Department of Thoracic Surgery, Peking University People's Hospital, Beijing 100044, China.
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9
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Datta A, Brosh RM. WRN rescues replication forks compromised by a BRCA2 deficiency: Predictions for how inhibition of a helicase that suppresses premature aging tilts the balance to fork demise and chromosomal instability in cancer. Bioessays 2022; 44:e2200057. [PMID: 35751457 PMCID: PMC9527950 DOI: 10.1002/bies.202200057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/03/2022] [Accepted: 06/08/2022] [Indexed: 11/08/2022]
Abstract
Hereditary breast and ovarian cancers are frequently attributed to germline mutations in the tumor suppressor genes BRCA1 and BRCA2. BRCA1/2 act to repair double-strand breaks (DSBs) and suppress the demise of unstable replication forks. Our work elucidated a dynamic interplay between BRCA2 and the WRN DNA helicase/exonuclease defective in the premature aging disorder Werner syndrome. WRN and BRCA2 participate in complementary pathways to stabilize replication forks in cancer cells, allowing them to proliferate. Whether the functional overlap of WRN and BRCA2 is relevant to replication at gaps between newly synthesized DNA fragments, protection of telomeres, and/or metabolism of secondary DNA structures remain to be determined. Advances in understanding the mechanisms elicited during replication stress have prompted the community to reconsider avenues for cancer therapy. Insights from studies of PARP or topoisomerase inhibitors provide working models for the investigation of WRN's mechanism of action. We discuss these topics, focusing on the implications of the WRN-BRCA2 genetic interaction under conditions of replication stress.
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Affiliation(s)
- Arindam Datta
- Helicases and Genomic Integrity Section, Translational Gerontology Branch, National Institute on Aging, NIH, Baltimore, Maryland, USA
| | - Robert M Brosh
- Helicases and Genomic Integrity Section, Translational Gerontology Branch, National Institute on Aging, NIH, Baltimore, Maryland, USA
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10
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Feng W, Smith CM, Simpson DA, Gupta GP. Targeting Non-homologous and Alternative End Joining Repair to Enhance Cancer Radiosensitivity. Semin Radiat Oncol 2021; 32:29-41. [PMID: 34861993 DOI: 10.1016/j.semradonc.2021.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Many cancer therapies, including radiotherapy, induce DSBs as the major driving mechanism for inducing cancer cell death. Thus, modulating DSB repair has immense potential for radiosensitization, although such interventions must be carefully designed to be tumor selective to ensure that normal tissue toxicities are not also increased. Here, we review mechanisms of error-prone DSB repair through a highly efficient process called end joining. There are two major pathways of end-joining repair: non-homologous end joining (NHEJ) and alternative end joining (a-EJ), both of which can be selectively upregulated in cancer and thus represent attractive therapeutic targets for radiosensitization. These EJ pathways each have therapeutically targetable pioneer factors - DNA-dependent protein kinase catalytic subunit (DNA-PKcs) for NHEJ and DNA Polymerase Theta (Pol θ) for a-EJ. We summarize the current status of therapeutic targeting of NHEJ and a-EJ to enhance the effects of radiotherapy - focusing on challenges that must be overcome and opportunities that require further exploration. By leveraging preclinical insights into mechanisms of altered DSB repair programs in cancer, selective radiosensitization through NHEJ and/or a-EJ targeting remains a highly attractive avenue for ongoing and future clinical investigation.
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Affiliation(s)
| | - Chelsea M Smith
- Lineberger Comprehensive Cancer Center; Pathobiology and Translational Science Graduate Program
| | | | - Gaorav P Gupta
- Lineberger Comprehensive Cancer Center; Pathobiology and Translational Science Graduate Program; Department of Radiation Oncology; Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC.
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11
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Roy U, Kwon Y, Sung P, Greene EC. Single-molecule studies of yeast Rad51 paralogs. Methods Enzymol 2021; 661:343-362. [PMID: 34776219 DOI: 10.1016/bs.mie.2021.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Homologous recombination (HR) is a conserved mechanism essential for the accurate repair of DNA double stranded breaks and the exchange of genetic information during meiosis. The key steps in HR are carried out by the RecA/Rad51 class of recombinases, which form a helical filament on single-stranded DNA (ssDNA) and catalyze homology search and strand exchange with a complementary duplex DNA target. In eukaryotes, assembly of the Rad51-ssDNA filament requires regulatory factors called mediators, including Rad51 paralogs. A mechanistic understanding of the role of Rad51 paralogs in HR has been hampered by the transient and diverse nature of intermediates formed with the Rad51-ssDNA filament, which cannot be resolved by traditional ensemble methods. The biochemical characterization of Rad51 paralogs, including the S. cerevisiae complex Rad55-Rad57 has also been limited by their propensity to aggregate. Here we describe the preparation of monodisperse GFP-tagged Rad55-Rad57 complex and the methodology for its analysis in our single-molecule DNA curtain assay.
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Affiliation(s)
- Upasana Roy
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY, United States
| | - Youngho Kwon
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, TX, United States
| | - Patrick Sung
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, TX, United States
| | - Eric C Greene
- Department of Biochemistry & Molecular Biophysics, Columbia University, New York, NY, United States.
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12
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Dai J, Jiang M, He K, Wang H, Chen P, Guo H, Zhao W, Lu H, He Y, Zhou C. DNA Damage Response and Repair Gene Alterations Increase Tumor Mutational Burden and Promote Poor Prognosis of Advanced Lung Cancer. Front Oncol 2021; 11:708294. [PMID: 34604048 PMCID: PMC8479169 DOI: 10.3389/fonc.2021.708294] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 08/06/2021] [Indexed: 01/10/2023] Open
Abstract
DNA damage response and repair (DDR) gene alterations increase tumor-infiltrating lymphocytes, genomic instability, and tumor mutational burden (TMB). Whether DDR-related alterations relate to therapeutic response and prognosis in lung cancer lacking oncogenic drivers remains unknown. Pretherapeutic cancer samples of 122 patients [86 non-small cell lung cancer and 36 small cell lung cancer (SCLC)] harboring no EGFR/ALK alterations were collected. Through whole-exome sequencing, we outlined DDR mutational landscape and determined relationships between DDR gene alterations and TMB or intratumoral heterogeneity. Then, we evaluated the impacts of DDR gene alterations on therapeutic response and prognosis and established a DDR-based model for prognosis prediction. In addition, we investigated somatic interactions of DDR genes and immunomodulatory genes, immune expression patterns, immune microenvironment, and immune infiltration characteristics between DDR-deficient and DDR-proficient samples. Samples from cBioportal datasets were utilized for verification. We found that deleterious DDR gene alterations were closely associated with higher TMB than proficient-types (p < 0.001). DDR mechanisms attach great importance to the determination of patients’ prognosis after chemotherapy, and alterations of base excision repair pathway in adenocarcinoma, nucleotide excision repair in squamous carcinoma, and homologous recombination pathway in SCLC tend to associate with worse progression-free survival to first-line chemotherapy (all p < 0.05). A predictive nomogram model was constructed incorporating DDR-related alterations, clinical stage, and smoking status, with the area under curve values of 0.692–0.789 for 1- and 2-year receiver operating characteristic curves in training and testing cohorts. Furthermore, DDR-altered tumors contained enhanced frequencies of alterations in various genes of human leukocyte antigen (HLA) class I pathway including TAP1 and TAP2 than DDR-proficient samples. DDR-deficient types had lower expressions of STING1 (p = 0.01), CD28 (p = 0.020), HLA-DRB6 (p = 0.014) in adenocarcinoma, lower TNFRSF4 (p = 0.017), and TGFB1 expressions (p = 0.033) in squamous carcinoma, and higher CD40 (p = 0.012) and TNFRSF14 expressions (p = 0.022) in SCLC. DDR alteration enhanced activated mast cells in adenocarcinoma (p = 0.044) and M2 macrophage in squamous carcinoma (p = 0.004) than DDR-proficient types. Collectively, DDR gene alterations in lung cancer without oncogenic drivers are positively associated with high TMB. Specific DDR gene alterations tend to associate with worse progression-free survival to initial chemotherapy.
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Affiliation(s)
- Jiawei Dai
- SJTU-Yale Joint Center for Biostatistics and Data Science, Department of Bioinformatics and Biostatistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Minlin Jiang
- Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, Shanghai, China.,Medical School, Tongji University, Shanghai, China
| | - Kan He
- SJTU-Yale Joint Center for Biostatistics and Data Science, Department of Bioinformatics and Biostatistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Hao Wang
- Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, Shanghai, China.,Medical School, Tongji University, Shanghai, China
| | - Peixin Chen
- Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, Shanghai, China.,Medical School, Tongji University, Shanghai, China
| | - Haoyue Guo
- Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, Shanghai, China.,Medical School, Tongji University, Shanghai, China
| | - Wencheng Zhao
- Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, Shanghai, China.,Medical School, Tongji University, Shanghai, China
| | - Hui Lu
- SJTU-Yale Joint Center for Biostatistics and Data Science, Department of Bioinformatics and Biostatistics, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yayi He
- Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, Shanghai, China.,Medical School, Tongji University, Shanghai, China
| | - Caicun Zhou
- Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University Medical School Cancer Institute, Tongji University School of Medicine, Shanghai, China
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13
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Siri SO, Martino J, Gottifredi V. Structural Chromosome Instability: Types, Origins, Consequences, and Therapeutic Opportunities. Cancers (Basel) 2021; 13:3056. [PMID: 34205328 PMCID: PMC8234978 DOI: 10.3390/cancers13123056] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 01/04/2023] Open
Abstract
Chromosomal instability (CIN) refers to an increased rate of acquisition of numerical and structural changes in chromosomes and is considered an enabling characteristic of tumors. Given its role as a facilitator of genomic changes, CIN is increasingly being considered as a possible therapeutic target, raising the question of which variables may convert CIN into an ally instead of an enemy during cancer treatment. This review discusses the origins of structural chromosome abnormalities and the cellular mechanisms that prevent and resolve them, as well as how different CIN phenotypes relate to each other. We discuss the possible fates of cells containing structural CIN, focusing on how a few cell duplication cycles suffice to induce profound CIN-mediated genome alterations. Because such alterations can promote tumor adaptation to treatment, we discuss currently proposed strategies to either avoid CIN or enhance CIN to a level that is no longer compatible with cell survival.
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Affiliation(s)
- Sebastián Omar Siri
- Cell Cycle and Genome Stability Laboratory, Fundación Instituto Leloir, C1405 BWE Buenos Aires, Argentina;
- Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C1405 BWE Buenos Aires, Argentina
| | - Julieta Martino
- Cell Cycle and Genome Stability Laboratory, Fundación Instituto Leloir, C1405 BWE Buenos Aires, Argentina;
| | - Vanesa Gottifredi
- Cell Cycle and Genome Stability Laboratory, Fundación Instituto Leloir, C1405 BWE Buenos Aires, Argentina;
- Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C1405 BWE Buenos Aires, Argentina
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14
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Pellestor F, Gaillard JB, Schneider A, Puechberty J, Gatinois V. Chromoanagenesis, the mechanisms of a genomic chaos. Semin Cell Dev Biol 2021; 123:90-99. [PMID: 33608210 DOI: 10.1016/j.semcdb.2021.01.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 01/22/2021] [Indexed: 02/07/2023]
Abstract
Designated under the name of chromoanagenesis, the phenomena of chromothripsis, chromanasynthesis and chromoplexy constitute new types of complex rearrangements, including many genomic alterations localized on a few chromosomal regions, and whose discovery over the last decade has changed our perception about the formation of chromosomal abnormalities and their etiology. Although exhibiting specific features, these new catastrophic mechanisms generally occur within a single cell cycle and their emergence is closely linked to genomic instability. Various non-exclusive exogenous or cellular mechanisms capable of generating chromoanagenesis have been evoked. However, recent experimental data shed light on 2 major processes, which following a defect in the mitotic segregation of chromosomes, can generate a cascade of cellular events leading to chromoanagenesis. These mechanisms are the formation of micronuclei integrating isolated chromosomal material, and the occurrence of chromatin bridges around chromosomal material resulting from telomeric fusions. In both cases, the cellular and molecular mechanisms of fragmentation, repair and transmission of damaged chromosomal material are consistent with the features of chromoanagenesis-related complex chromosomal rearrangements. In this review, we introduce each type of chromoanagenesis, and describe the experimental models that have allowed to validate the existence of chromoanagenesis events and to better understand their cellular mechanisms of formation and transmission, as well as their impact on the stability and the plasticity of the genome.
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Affiliation(s)
- F Pellestor
- Unit of Chromosomal Genetics and Research Plateform Chromostem, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, 371 avenue du Doyen Gaston Giraud, Montpellier Cedex 5 34295, France; INSERM 1183 Unit "Genome and Stem Cell Plasticity in Development and Aging" Institute of Regenerative Medecine and Biotherapies, St Eloi Hospital, Montpellier, France.
| | - J B Gaillard
- Unit of Chromosomal Genetics and Research Plateform Chromostem, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, 371 avenue du Doyen Gaston Giraud, Montpellier Cedex 5 34295, France
| | - A Schneider
- Unit of Chromosomal Genetics and Research Plateform Chromostem, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, 371 avenue du Doyen Gaston Giraud, Montpellier Cedex 5 34295, France
| | - J Puechberty
- Unit of Chromosomal Genetics and Research Plateform Chromostem, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, 371 avenue du Doyen Gaston Giraud, Montpellier Cedex 5 34295, France
| | - V Gatinois
- Unit of Chromosomal Genetics and Research Plateform Chromostem, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, 371 avenue du Doyen Gaston Giraud, Montpellier Cedex 5 34295, France; INSERM 1183 Unit "Genome and Stem Cell Plasticity in Development and Aging" Institute of Regenerative Medecine and Biotherapies, St Eloi Hospital, Montpellier, France
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15
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Patel PS, Abraham KJ, Guturi KKN, Halaby MJ, Khan Z, Palomero L, Ho B, Duan S, St-Germain J, Algouneh A, Mateo F, El Ghamrasni S, Barbour H, Barnes DR, Beesley J, Sanchez O, Berman HK, Brown GW, El Bachir Affar, Chenevix-Trench G, Antoniou AC, Arrowsmith CH, Raught B, Pujana MA, Mekhail K, Hakem A, Hakem R. RNF168 regulates R-loop resolution and genomic stability in BRCA1/2-deficient tumors. J Clin Invest 2021; 131:140105. [PMID: 33529165 PMCID: PMC7843228 DOI: 10.1172/jci140105] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 12/09/2020] [Indexed: 12/23/2022] Open
Abstract
Germline mutations in BRCA1 and BRCA2 (BRCA1/2) genes considerably increase breast and ovarian cancer risk. Given that tumors with these mutations have elevated genomic instability, they exhibit relative vulnerability to certain chemotherapies and targeted treatments based on poly (ADP-ribose) polymerase (PARP) inhibition. However, the molecular mechanisms that influence cancer risk and therapeutic benefit or resistance remain only partially understood. BRCA1 and BRCA2 have also been implicated in the suppression of R-loops, triple-stranded nucleic acid structures composed of a DNA:RNA hybrid and a displaced ssDNA strand. Here, we report that loss of RNF168, an E3 ubiquitin ligase and DNA double-strand break (DSB) responder, remarkably protected Brca1-mutant mice against mammary tumorigenesis. We demonstrate that RNF168 deficiency resulted in accumulation of R-loops in BRCA1/2-mutant breast and ovarian cancer cells, leading to DSBs, senescence, and subsequent cell death. Using interactome assays, we identified RNF168 interaction with DHX9, a helicase involved in the resolution and removal of R-loops. Mechanistically, RNF168 directly ubiquitylated DHX9 to facilitate its recruitment to R-loop-prone genomic loci. Consequently, loss of RNF168 impaired DHX9 recruitment to R-loops, thereby abrogating its ability to resolve R-loops. The data presented in this study highlight a dependence of BRCA1/2-defective tumors on factors that suppress R-loops and reveal a fundamental RNF168-mediated molecular mechanism that governs cancer development and vulnerability.
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Affiliation(s)
- Parasvi S. Patel
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, and
| | - Karan Joshua Abraham
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Kiran Kumar Naidu Guturi
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, and
| | - Marie-Jo Halaby
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, and
| | - Zahra Khan
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, and
| | - Luis Palomero
- Program Against Cancer Therapeutic Resistance (ProCURE), Catalan Institute of Oncology (ICO), Bellvitge Institute for Biomedical Research (IDIBELL), L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain
| | - Brandon Ho
- Department of Biochemistry and Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - Shili Duan
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, and
| | - Jonathan St-Germain
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, and
| | - Arash Algouneh
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Francesca Mateo
- Program Against Cancer Therapeutic Resistance (ProCURE), Catalan Institute of Oncology (ICO), Bellvitge Institute for Biomedical Research (IDIBELL), L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain
| | - Samah El Ghamrasni
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, and
| | - Haithem Barbour
- Centre de Recherche, Hôpital Maisonneuve-Rosemont, Montreal, Quebec, Canada
| | - Daniel R. Barnes
- Centre for Cancer Genetic Epidemiology, Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom
| | - Jonathan Beesley
- Cancer Division, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Otto Sanchez
- University of Ontario Institute of Technology, Oshawa, Ontario, Canada
| | - Hal K. Berman
- Toronto General Research Institute, Toronto, Ontario, Canada
| | - Grant W. Brown
- Department of Biochemistry and Donnelly Centre, University of Toronto, Toronto, Ontario, Canada
| | - El Bachir Affar
- Centre de Recherche, Hôpital Maisonneuve-Rosemont, Montreal, Quebec, Canada
| | | | - Antonis C. Antoniou
- Centre for Cancer Genetic Epidemiology, Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom
| | - Cheryl H. Arrowsmith
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, and
| | - Brian Raught
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, and
| | - Miquel Angel Pujana
- Program Against Cancer Therapeutic Resistance (ProCURE), Catalan Institute of Oncology (ICO), Bellvitge Institute for Biomedical Research (IDIBELL), L’Hospitalet del Llobregat, Barcelona, Catalonia, Spain
| | - Karim Mekhail
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Anne Hakem
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, and
| | - Razqallah Hakem
- Princess Margaret Cancer Centre, University Health Network and Department of Medical Biophysics, and
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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16
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Abstract
Bladder cancer has been successfully treated with immunotherapy, whereas prostate cancer is a cold tumor with inadequate immune-related treatment response. A greater understanding of the tumor microenvironment and methods for harnessing the immune system to address tumor growth will be needed to improve immunotherapies for both prostate and bladder cancer. Here, we provide an overview of prostate and bladder cancer, including fundamental aspects of the disease and treatment, the elaborate cellular makeup of the tumor microenvironment, and methods for exploiting relevant pathways to develop more effective treatments.
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17
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Roy U, Greene EC. Single-Stranded DNA Curtains for Single-Molecule Visualization of Rad51-ssDNA Filament Dynamics. Methods Mol Biol 2021; 2281:193-207. [PMID: 33847959 DOI: 10.1007/978-1-0716-1290-3_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Homologous recombination (HR) is a highly conserved DNA repair pathway required for the accurate repair of DNA double-stranded breaks. DNA recombination is catalyzed by the RecA/Rad51 family of proteins, which are conserved from bacteria to humans. The key intermediate catalyzing DNA recombination is the presynaptic complex (PSC), which is a helical filament comprised of Rad51-bound single-stranded DNA (ssDNA). Multiple cellular factors either promote or downregulate PSC activity, and a fine balance between such regulators is required for the proper regulation of HR and maintenance of genomic integrity. However, dissecting the complex mechanisms regulating PSC activity has been a challenge using traditional ensemble methods due to the transient and dynamic nature of recombination intermediates. We have developed a single-molecule assay called ssDNA curtains that allows us to visualize individual DNA intermediates in real-time, using total internal reflection microscopy (TIRFM). This assay has allowed us to study many aspects of HR regulation that involve complex and heterogenous reaction intermediates. Here we describe the procedure for a basic ssDNA curtain assay to study PSC filament dynamics, and explain how to process and analyze the resulting data.
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Affiliation(s)
- Upasana Roy
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Eric C Greene
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
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18
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Götting I, Jendrossek V, Matschke J. A New Twist in Protein Kinase B/Akt Signaling: Role of Altered Cancer Cell Metabolism in Akt-Mediated Therapy Resistance. Int J Mol Sci 2020; 21:ijms21228563. [PMID: 33202866 PMCID: PMC7697684 DOI: 10.3390/ijms21228563] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/23/2020] [Accepted: 11/09/2020] [Indexed: 12/11/2022] Open
Abstract
Cancer resistance to chemotherapy, radiotherapy and molecular-targeted agents is a major obstacle to successful cancer therapy. Herein, aberrant activation of the phosphatidyl-inositol-3-kinase (PI3K)/protein kinase B (Akt) pathway is one of the most frequently deregulated pathways in cancer cells and has been associated with multiple aspects of therapy resistance. These include, for example, survival under stress conditions, apoptosis resistance, activation of the cellular response to DNA damage and repair of radiation-induced or chemotherapy-induced DNA damage, particularly DNA double strand breaks (DSB). One further important, yet not much investigated aspect of Akt-dependent signaling is the regulation of cell metabolism. In fact, many Akt target proteins are part of or involved in the regulation of metabolic pathways. Furthermore, recent studies revealed the importance of certain metabolites for protection against therapy-induced cell stress and the repair of therapy-induced DNA damage. Thus far, the likely interaction between deregulated activation of Akt, altered cancer metabolism and therapy resistance is not yet well understood. The present review describes the documented interactions between Akt, its target proteins and cancer cell metabolism, focusing on antioxidant defense and DSB repair. Furthermore, the review highlights potential connections between deregulated Akt, cancer cell metabolism and therapy resistance of cancer cells through altered DSB repair and discusses potential resulting therapeutic implications.
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19
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Patterson-Fortin J, D'Andrea AD. Exploiting the Microhomology-Mediated End-Joining Pathway in Cancer Therapy. Cancer Res 2020; 80:4593-4600. [PMID: 32651257 PMCID: PMC7641946 DOI: 10.1158/0008-5472.can-20-1672] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/13/2020] [Accepted: 07/07/2020] [Indexed: 01/16/2023]
Abstract
Repair of DNA double-strand breaks (DSB) is performed by two major pathways, homology-dependent repair and classical nonhomologous end-joining. Recent studies have identified a third pathway, microhomology-mediated end-joining (MMEJ). MMEJ has similarities to homology-dependent repair, in that repair is initiated with end resection, leading to single-stranded 3' ends, which require microhomology upstream and downstream of the DSB. Importantly, the MMEJ pathway is commonly upregulated in cancers, especially in homologous recombination-deficient cancers, which display a distinctive mutational signature. Here, we review the molecular process of MMEJ as well as new targets and approaches exploiting the MMEJ pathway in cancer therapy.
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Affiliation(s)
| | - Alan D D'Andrea
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.
- Center for DNA Damage and Repair, Dana-Farber Cancer Institute, Boston, Massachusetts
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20
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Hays E, Nettleton E, Carter C, Morales M, Vo L, Passo M, Vélez-Cruz R. The SWI/SNF ATPase BRG1 stimulates DNA end resection and homologous recombination by reducing nucleosome density at DNA double strand breaks and by promoting the recruitment of the CtIP nuclease. Cell Cycle 2020; 19:3096-3114. [PMID: 33044911 PMCID: PMC7714457 DOI: 10.1080/15384101.2020.1831256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
DNA double strand breaks (DSBs) are among the most toxic DNA lesions and can be repaired accurately through homologous recombination (HR). HR requires processing of the DNA ends by nucleases (DNA end resection) in order to generate the required single-stranded DNA (ssDNA) regions. The SWI/SNF chromatin remodelers are 10–15 subunit complexes that contain one ATPase (BRG1 or BRM). Multiple subunits of these complexes have recently been identified as a novel family of tumor suppressors. These complexes are capable of remodeling chromatin by pushing nucleosomes along the DNA. More recent studies have identified these chromatin remodelers as important factors in DNA repair. Using the DR-U2OS reporter system, we show that the down regulation of BRG1 significantly reduces HR efficiency, while BRM has a minor effect. Inactivation of BRG1 impairs DSB repair and results in a defect in DNA end resection, as measured by the amount of BrdU-containing ssDNA generated after DNA damage. Inactivation of BRG1 also impairs the activation of the ATR kinase, reduces the levels of chromatin-bound RPA, and reduces the number of RPA and RAD51 foci after DNA damage. This defect in DNA end resection is explained by the defective recruitment of GFP-CtIP to laser-induced DSBs in the absence of BRG1. Importantly, we show that BRG1 reduces nucleosome density at DSBs. Finally, inactivation of BRG1 renders cells sensitive to anti-cancer drugs that induce DSBs. This study identifies BRG1 as an important factor for HR, which suggests that BRG1-mutated cancers have a DNA repair vulnerability that can be exploited therapeutically.
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Affiliation(s)
- Emily Hays
- Department of Biochemistry and Molecular Genetics, Midwestern University , Downers Grove, IL, USA.,College of Graduate Studies, Midwestern University , Downers Grove, IL, USA
| | - Elizabeth Nettleton
- Chicago College of Osteopathic Medicine, Midwestern University , Downers Grove, IL, USA
| | - Caitlin Carter
- Chicago College of Osteopathic Medicine, Midwestern University , Downers Grove, IL, USA
| | - Mariangel Morales
- College of Graduate Studies, Midwestern University , Downers Grove, IL, USA.,Biomedical Sciences Program, Midwestern University , Downers Grove, IL, USA
| | - Lynn Vo
- Chicago College of Osteopathic Medicine, Midwestern University , Downers Grove, IL, USA
| | - Max Passo
- College of Graduate Studies, Midwestern University , Downers Grove, IL, USA.,Biomedical Sciences Program, Midwestern University , Downers Grove, IL, USA
| | - Renier Vélez-Cruz
- Department of Biochemistry and Molecular Genetics, Midwestern University , Downers Grove, IL, USA.,College of Graduate Studies, Midwestern University , Downers Grove, IL, USA.,Chicago College of Optometry, Midwestern University , Downers Grove, IL, USA
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21
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Loeillet S, Herzog M, Puddu F, Legoix P, Baulande S, Jackson SP, Nicolas AG. Trajectory and uniqueness of mutational signatures in yeast mutators. Proc Natl Acad Sci U S A 2020; 117:24947-24956. [PMID: 32968016 PMCID: PMC7547211 DOI: 10.1073/pnas.2011332117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The acquisition of mutations plays critical roles in adaptation, evolution, senescence, and tumorigenesis. Massive genome sequencing has allowed extraction of specific features of many mutational landscapes but it remains difficult to retrospectively determine the mechanistic origin(s), selective forces, and trajectories of transient or persistent mutations and genome rearrangements. Here, we conducted a prospective reciprocal approach to inactivate 13 single or multiple evolutionary conserved genes involved in distinct genome maintenance processes and characterize de novo mutations in 274 diploid Saccharomyces cerevisiae mutation accumulation lines. This approach revealed the diversity, complexity, and ultimate uniqueness of mutational landscapes, differently composed of base substitutions, small insertions/deletions (InDels), structural variants, and/or ploidy variations. Several landscapes parallel the repertoire of mutational signatures in human cancers while others are either novel or composites of subsignatures resulting from distinct DNA damage lesions. Notably, the increase of base substitutions in the homologous recombination-deficient Rad51 mutant, specifically dependent on the Polζ translesion polymerase, yields COSMIC signature 3 observed in BRCA1/BRCA2-mutant breast cancer tumors. Furthermore, "mutome" analyses in highly polymorphic diploids and single-cell bottleneck lineages revealed a diverse spectrum of loss-of-heterozygosity (LOH) signatures characterized by interstitial and terminal chromosomal events resulting from interhomolog mitotic cross-overs. Following the appearance of heterozygous mutations, the strong stimulation of LOHs in the rad27/FEN1 and tsa1/PRDX1 backgrounds leads to fixation of homozygous mutations or their loss along the lineage. Overall, these mutomes and their trajectories provide a mechanistic framework to understand the origin and dynamics of genome variations that accumulate during clonal evolution.
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Affiliation(s)
- Sophie Loeillet
- Institut Curie, Paris Sciences et Lettres Research University, CNRS, UMR3244, 75248 Paris Cedex 05, France
- Sorbonne Universités, Université Pierre et Marie Curie Paris 06, CNRS, UMR3244, 75248 Paris Cedex 05, France
| | - Mareike Herzog
- Wellcome/Cancer Research UK Gurdon Institute and Department of Biochemistry, Cambridge CB2 1QN, United Kingdom
| | - Fabio Puddu
- Wellcome/Cancer Research UK Gurdon Institute and Department of Biochemistry, Cambridge CB2 1QN, United Kingdom
| | - Patricia Legoix
- ICGex NGS Platform, Institut Curie, 75248 Paris Cedex 05, France
| | - Sylvain Baulande
- ICGex NGS Platform, Institut Curie, 75248 Paris Cedex 05, France
| | - Stephen P Jackson
- Wellcome/Cancer Research UK Gurdon Institute and Department of Biochemistry, Cambridge CB2 1QN, United Kingdom
| | - Alain G Nicolas
- Institut Curie, Paris Sciences et Lettres Research University, CNRS, UMR3244, 75248 Paris Cedex 05, France;
- Sorbonne Universités, Université Pierre et Marie Curie Paris 06, CNRS, UMR3244, 75248 Paris Cedex 05, France
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22
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Gao A, Guo M. Epigenetic based synthetic lethal strategies in human cancers. Biomark Res 2020; 8:44. [PMID: 32974031 PMCID: PMC7493427 DOI: 10.1186/s40364-020-00224-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 09/04/2020] [Indexed: 02/08/2023] Open
Abstract
Over the past decades, it is recognized that loss of DNA damage repair (DDR) pathways is an early and frequent event in tumorigenesis, occurring in 40-50% of many cancer types. The basis of synthetic lethality in cancer therapy is DDR deficient cancers dependent on backup DNA repair pathways. In cancer, the concept of synthetic lethality has been extended to pairs of genes, in which inactivation of one by deletion or mutation and pharmacological inhibition of the other leads to death of cancer cells whereas normal cells are spared the effect of the drug. The paradigm study is to induce cell death by inhibiting PARP in BRCA1/2 defective cells. Since the successful application of PARP inhibitor, a growing number of developed DDR inhibitors are ongoing in preclinical and clinical testing, including ATM, ATR, CHK1/2 and WEE1 inhibitors. Combination of PARP inhibitors and other DDR inhibitors, or combination of multiple components of the same pathway may have great potential synthetic lethality efficiency. As epigenetics joins Knudson’s two hit theory, silencing of DDR genes by aberrant epigenetic changes provide new opportunities for synthetic lethal therapy in cancer. Understanding the causative epigenetic changes of loss-of-function has led to the development of novel therapeutic agents in cancer. DDR and related genes were found frequently methylated in human cancers, including BRCA1/2, MGMT, WRN, MLH1, CHFR, P16 and APC. Both genetic and epigenetic alterations may serve as synthetic lethal therapeutic markers.
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Affiliation(s)
- Aiai Gao
- Department of Gastroenterology and Hepatology, Chinese PLA General Hospital, #28 Fuxing Road, Beijing, 100853 China
| | - Mingzhou Guo
- Department of Gastroenterology and Hepatology, Chinese PLA General Hospital, #28 Fuxing Road, Beijing, 100853 China.,Henan Key Laboratory for Esophageal Cancer Research, Zhengzhou University, 40 Daxue Road, Zhengzhou, 450052 Henan China.,State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital, #28 Fuxing Road, Beijing, 100853 China
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23
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Xiang K, Jendrossek V, Matschke J. Oncometabolites and the response to radiotherapy. Radiat Oncol 2020; 15:197. [PMID: 32799884 PMCID: PMC7429799 DOI: 10.1186/s13014-020-01638-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/06/2020] [Indexed: 12/18/2022] Open
Abstract
Radiotherapy (RT) is applied in 45–60% of all cancer patients either alone or in multimodal therapy concepts comprising surgery, RT and chemotherapy. However, despite technical innovations approximately only 50% are cured, highlight a high medical need for innovation in RT practice. RT is a multidisciplinary treatment involving medicine and physics, but has always been successful in integrating emerging novel concepts from cancer and radiation biology for improving therapy outcome. Currently, substantial improvements are expected from integration of precision medicine approaches into RT concepts. Altered metabolism is an important feature of cancer cells and a driving force for malignant progression. Proper metabolic processes are essential to maintain and drive all energy-demanding cellular processes, e.g. repair of DNA double-strand breaks (DSBs). Consequently, metabolic bottlenecks might allow therapeutic intervention in cancer patients. Increasing evidence now indicates that oncogenic activation of metabolic enzymes, oncogenic activities of mutated metabolic enzymes, or adverse conditions in the tumor microenvironment can result in abnormal production of metabolites promoting cancer progression, e.g. 2-hyroxyglutarate (2-HG), succinate and fumarate, respectively. Interestingly, these so-called “oncometabolites” not only modulate cell signaling but also impact the response of cancer cells to chemotherapy and RT, presumably by epigenetic modulation of DNA repair. Here we aimed to introduce the biological basis of oncometabolite production and of their actions on epigenetic regulation of DNA repair. Furthermore, the review will highlight innovative therapeutic opportunities arising from the interaction of oncometabolites with DNA repair regulation for specifically enhancing the therapeutic effects of genotoxic treatments including RT in cancer patients.
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Affiliation(s)
- Kexu Xiang
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, Virchowstrasse 173, 45147, Essen, Germany
| | - Verena Jendrossek
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, Virchowstrasse 173, 45147, Essen, Germany
| | - Johann Matschke
- Institute of Cell Biology (Cancer Research), University Hospital Essen, University of Duisburg-Essen, Virchowstrasse 173, 45147, Essen, Germany.
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24
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Liu Y, Lu LY. BRCA1 and homologous recombination: implications from mouse embryonic development. Cell Biosci 2020; 10:49. [PMID: 32257107 PMCID: PMC7106644 DOI: 10.1186/s13578-020-00412-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 03/18/2020] [Indexed: 01/30/2023] Open
Abstract
As an important player in DNA damage response, BRCA1 maintains genomic stability and suppresses tumorigenesis by promoting DNA double-strand break (DSB) repair through homologous recombination (HR). Since the cloning of BRCA1 gene, many Brca1 mutant alleles have been generated in mice. Mice carrying homozygous Brca1 mutant alleles are embryonic lethal, suggesting that BRCA1's functions are important for embryonic development. Studies of embryonic development in Brca1 mutant mice not only reveal the physiological significance of BRCA1's known function in HR, but also lead to the discovery of BRCA1's new function in HR: regulation of DSB repair pathway choice.
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Affiliation(s)
- Yidan Liu
- 1Key Laboratory of Reproductive Genetics (Ministry of Education) and Women's Reproductive Health Laboratory of Zhejiang Province, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lin-Yu Lu
- 1Key Laboratory of Reproductive Genetics (Ministry of Education) and Women's Reproductive Health Laboratory of Zhejiang Province, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.,2Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
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25
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Chen J, Li P, Song L, Bai L, Huen MSY, Liu Y, Lu LY. 53BP1 loss rescues embryonic lethality but not genomic instability of BRCA1 total knockout mice. Cell Death Differ 2020; 27:2552-2567. [PMID: 32139898 PMCID: PMC7429965 DOI: 10.1038/s41418-020-0521-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 02/18/2020] [Accepted: 02/19/2020] [Indexed: 12/29/2022] Open
Abstract
BRCA1 is critical for DNA double-strand break (DSB) repair by homologous recombination (HR). BRCA1 deficient mice are embryonic lethal. Previous studies have shown that 53BP1 knockout (KO) rescues embryonic lethality of BRCA1 hypomorphic mutant mice by restoring HR. Here, we show that 53BP1 KO can partially rescue embryonic lethality of BRCA1 total KO mice, but HR is not restored in BRCA1-53BP1 double knockout (DKO) mice. As a result, BRCA1-53BP1 DKO cells are extremely sensitive to PARP inhibitors (PARPi). In addition to HR deficiency, BRCA1-53BP1 DKO cells have elevated microhomology-mediated end joining (MMEJ) activity and G2/M cell cycle checkpoint defects, causing severe genomic instability in these cells. Interestingly, BRCA1-53BP1 DKO mice rapidly develop thymic lymphoma that is 100% penetrant, which is not observed in any BRCA1 mutant mice rescued by 53BP1 KO. Taken together, our study reveals that 53BP1 KO can partially rescue embryonic lethality caused by complete BRCA1 loss without rescuing HR-related defects. This finding suggests that loss of 53BP1 can support the development of cancers with silenced BRCA1 expression without causing PARPi resistance.
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Affiliation(s)
- Jiyuan Chen
- Key Laboratory of Reproductive Genetics (Ministry of Education) and Women's Reproductive Health Laboratory of Zhejiang Province, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Peng Li
- Key Laboratory of Reproductive Genetics (Ministry of Education) and Women's Reproductive Health Laboratory of Zhejiang Province, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Licun Song
- Key Laboratory of Reproductive Genetics (Ministry of Education) and Women's Reproductive Health Laboratory of Zhejiang Province, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Long Bai
- Key Laboratory of Reproductive Genetics (Ministry of Education) and Women's Reproductive Health Laboratory of Zhejiang Province, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Michael S Y Huen
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Yidan Liu
- Key Laboratory of Reproductive Genetics (Ministry of Education) and Women's Reproductive Health Laboratory of Zhejiang Province, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.
| | - Lin-Yu Lu
- Key Laboratory of Reproductive Genetics (Ministry of Education) and Women's Reproductive Health Laboratory of Zhejiang Province, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China. .,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China.
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26
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RAD52: Viral Friend or Foe? Cancers (Basel) 2020; 12:cancers12020399. [PMID: 32046320 PMCID: PMC7072633 DOI: 10.3390/cancers12020399] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/06/2020] [Accepted: 02/06/2020] [Indexed: 02/06/2023] Open
Abstract
Mammalian Radiation Sensitive 52 (RAD52) is a gene whose scientific reputation has recently seen a strong resurgence. In the past decade, RAD52, which was thought to be dispensable for most DNA repair and recombination reactions in mammals, has been shown to be important for a bevy of DNA metabolic pathways. One of these processes is termed break-induced replication (BIR), a mechanism that can be used to re-start broken replication forks and to elongate the ends of chromosomes in telomerase-negative cells. Viruses have historically evolved a myriad of mechanisms in which they either conscript cellular factors or, more frequently, inactivate them as a means to enable their own replication and survival. Recent data suggests that Adeno-Associated Virus (AAV) may replicate its DNA in a BIR-like fashion and/or utilize RAD52 to facilitate viral transduction and, as such, likely conscripts/requires the host RAD52 protein to promote its perpetuation.
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27
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Sakofsky CJ, Saini N, Klimczak LJ, Chan K, Malc EP, Mieczkowski PA, Burkholder AB, Fargo D, Gordenin DA. Repair of multiple simultaneous double-strand breaks causes bursts of genome-wide clustered hypermutation. PLoS Biol 2019; 17:e3000464. [PMID: 31568516 PMCID: PMC6786661 DOI: 10.1371/journal.pbio.3000464] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/10/2019] [Accepted: 09/12/2019] [Indexed: 12/17/2022] Open
Abstract
A single cancer genome can harbor thousands of clustered mutations. Mutation signature analyses have revealed that the origin of clusters are lesions in long tracts of single-stranded (ss) DNA damaged by apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) cytidine deaminases, raising questions about molecular mechanisms that generate long ssDNA vulnerable to hypermutation. Here, we show that ssDNA intermediates formed during the repair of gamma-induced bursts of double-strand breaks (DSBs) in the presence of APOBEC3A in yeast lead to multiple APOBEC-induced clusters similar to cancer. We identified three independent pathways enabling cluster formation associated with repairing bursts of DSBs: 5′ to 3′ bidirectional resection, unidirectional resection, and break-induced replication (BIR). Analysis of millions of mutations in APOBEC-hypermutated cancer genomes revealed that cancer tolerance to formation of hypermutable ssDNA is similar to yeast and that the predominant pattern of clustered mutagenesis is the same as in resection-defective yeast, suggesting that cluster formation in cancers is driven by a BIR-like mechanism. The phenomenon of genome-wide burst of clustered mutagenesis revealed by our study can play an important role in generating somatic hypermutation in cancers as well as in noncancerous cells. This study uses yeast expressing a human cytidine deaminase to reveal simultaneous stretches of long single-strand DNA and multiple vast mutation clusters in a single eukaryotic cell repairing multiple double-strand breaks. This is reminiscent of the phenomenon of “kataegis” or hypermutation observed in cancer genomes, suggesting that a similar mechanism is involved.
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Affiliation(s)
- Cynthia J. Sakofsky
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, US National Institutes of Health, North Carolina, United States of America
| | - Natalie Saini
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, US National Institutes of Health, North Carolina, United States of America
| | - Leszek J. Klimczak
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences, US National Institutes of Health, North Carolina, United States of America
| | - Kin Chan
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, US National Institutes of Health, North Carolina, United States of America
| | - Ewa P. Malc
- Department of Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Piotr A. Mieczkowski
- Department of Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Adam B. Burkholder
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences, US National Institutes of Health, North Carolina, United States of America
| | - David Fargo
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences, US National Institutes of Health, North Carolina, United States of America
| | - Dmitry A. Gordenin
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, US National Institutes of Health, North Carolina, United States of America
- * E-mail:
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28
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Feng W, Simpson DA, Carvajal-Garcia J, Price BA, Kumar RJ, Mose LE, Wood RD, Rashid N, Purvis JE, Parker JS, Ramsden DA, Gupta GP. Genetic determinants of cellular addiction to DNA polymerase theta. Nat Commun 2019; 10:4286. [PMID: 31537809 PMCID: PMC6753077 DOI: 10.1038/s41467-019-12234-1] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 08/22/2019] [Indexed: 02/07/2023] Open
Abstract
Polymerase theta (Pol θ, gene name Polq) is a widely conserved DNA polymerase that mediates a microhomology-mediated, error-prone, double strand break (DSB) repair pathway, referred to as Theta Mediated End Joining (TMEJ). Cells with homologous recombination deficiency are reliant on TMEJ for DSB repair. It is unknown whether deficiencies in other components of the DNA damage response (DDR) also result in Pol θ addiction. Here we use a CRISPR genetic screen to uncover 140 Polq synthetic lethal (PolqSL) genes, the majority of which were previously unknown. Functional analyses indicate that Pol θ/TMEJ addiction is associated with increased levels of replication-associated DSBs, regardless of the initial source of damage. We further demonstrate that approximately 30% of TCGA breast cancers have genetic alterations in PolqSL genes and exhibit genomic scars of Pol θ/TMEJ hyperactivity, thereby substantially expanding the subset of human cancers for which Pol θ inhibition represents a promising therapeutic strategy.
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Affiliation(s)
- Wanjuan Feng
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Dennis A Simpson
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Juan Carvajal-Garcia
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Brandon A Price
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Rashmi J Kumar
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Lisle E Mose
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Richard D Wood
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Smithville, TX, 78957, USA
| | - Naim Rashid
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jeremy E Purvis
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Joel S Parker
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Dale A Ramsden
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Gaorav P Gupta
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
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29
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Gómez-Miragaya J, Díaz-Navarro A, Tonda R, Beltran S, Palomero L, Palafox M, Dobrolecki LE, Huang C, Vasaikar S, Zhang B, Wulf GM, Collado-Sole A, Trinidad EM, Muñoz P, Paré L, Prat A, Bruna A, Caldas C, Arribas J, Soler-Monso MT, Petit A, Balmaña J, Cruz C, Serra V, Pujana MA, Lewis MT, Puente XS, González-Suárez E. Chromosome 12p Amplification in Triple-Negative/ BRCA1-Mutated Breast Cancer Associates with Emergence of Docetaxel Resistance and Carboplatin Sensitivity. Cancer Res 2019; 79:4258-4270. [PMID: 31213465 DOI: 10.1158/0008-5472.can-18-3835] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 03/05/2019] [Accepted: 06/07/2019] [Indexed: 11/16/2022]
Abstract
Taxanes are the mainstay of treatment in triple-negative breast cancer (TNBC), with de novo and acquired resistance limiting patient's survival. To investigate the genetic basis of docetaxel resistance in TNBC, exome sequencing was performed on matched TNBC patient-derived xenografts (PDX) sensitive to docetaxel and their counterparts that developed resistance in vivo upon continuous drug exposure. Most mutations, small insertions/deletions, and copy number alterations detected in the initial TNBC human metastatic samples were maintained after serial passages in mice and emergence of resistance. We identified a chromosomal amplification of chr12p in a human BRCA1-mutated metastatic sample and the derived chemoresistant PDX, but not in the matched docetaxel-sensitive PDX tumor. Chr12p amplification was validated in a second pair of docetaxel-sensitive/resistant BRCA1-mutated PDXs and after short-term docetaxel treatment in several TNBC/BRCA1-mutated PDXs and cell lines, as well as during metastatic recurrence in a patient with BRCA1-mutated breast cancer who had progressed on docetaxel treatment. Analysis of clinical data indicates an association between chr12p amplification and patients with TNBC/basal-like breast cancer, a BRCA1 mutational signature, and poor survival after chemotherapy. Detection of chr12p amplification in a cohort of TNBC PDX models was associated with an improved response to carboplatin. Our findings reveal tumor clonal dynamics during chemotherapy treatments and suggest that a preexisting population harboring chr12p amplification is associated with the emergence of docetaxel resistance and carboplatin responsiveness in TNBC/BRCA1-mutated tumors. SIGNIFICANCE: Chr12p copy number gains indicate rapid emergence of resistance to docetaxel and increased sensitivity to carboplatin, therefore sequential docetaxel/carboplatin treatment could improve survival in TNBC/BRCA1 patients. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/16/4258/F1.large.jpg.
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Affiliation(s)
- Jorge Gómez-Miragaya
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Avinguda de la Gran Via, 199-203, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Ander Díaz-Navarro
- Departamento de Bioquímica y Biología Molecular, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), CIBERONC, Universidad de Oviedo, Oviedo, Spain
| | - Raul Tonda
- CNAG-CRG, Centre for Genomic Regulation (CRG), Institute of Science and Technology (BIST), Centre for Genomic Analysis (CNAG), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Sergi Beltran
- CNAG-CRG, Centre for Genomic Regulation (CRG), Institute of Science and Technology (BIST), Centre for Genomic Analysis (CNAG), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Luis Palomero
- Breast Cancer and Systems Biology Laboratory, Program Against Cancer Therapeutic Resistance (ProCURE), Catalan Institute of Oncology (ICO), Oncobell, Bellvitge Institute for Biomedical Research (IDIBELL), L'Hospitalet del Llobregat, Barcelona, Spain
| | - Marta Palafox
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Avinguda de la Gran Via, 199-203, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Lacey E Dobrolecki
- Departments of Molecular and Cellular Biology and Radiology, The Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas
| | - Chen Huang
- Departments of Molecular and Human Genetics, The Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas
| | - Suhas Vasaikar
- Departments of Molecular and Human Genetics, The Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas
| | - Bing Zhang
- Departments of Molecular and Human Genetics, The Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas
| | - Gerburg M Wulf
- Division of Hematology/Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Alejandro Collado-Sole
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Avinguda de la Gran Via, 199-203, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Eva M Trinidad
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Avinguda de la Gran Via, 199-203, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Purificación Muñoz
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Avinguda de la Gran Via, 199-203, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Laia Paré
- Translational Genomics and Targeted Therapeutics in Solid Tumors, Institut D'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - Aleix Prat
- Translational Genomics and Targeted Therapeutics in Solid Tumors, Institut D'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
- Department of Medical Oncology, Hospital Clinic, Barcelona, Spain
| | - Alejandra Bruna
- Cancer Research UK Cancer Centre, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Carlos Caldas
- Cancer Research UK Cancer Centre, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Joaquín Arribas
- Preclinical Research Program, Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | | | - Anna Petit
- Pathology Department, University Hospital of Bellvitge, IDIBELL, Barcelona, Spain
| | - Judith Balmaña
- Preclinical Research Program, Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Cristina Cruz
- Preclinical Research Program, Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Violeta Serra
- Preclinical Research Program, Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Miguel Angel Pujana
- Breast Cancer and Systems Biology Laboratory, Program Against Cancer Therapeutic Resistance (ProCURE), Catalan Institute of Oncology (ICO), Oncobell, Bellvitge Institute for Biomedical Research (IDIBELL), L'Hospitalet del Llobregat, Barcelona, Spain
| | - Michael T Lewis
- Departments of Molecular and Cellular Biology and Radiology, The Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas
| | - Xose S Puente
- Departamento de Bioquímica y Biología Molecular, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), CIBERONC, Universidad de Oviedo, Oviedo, Spain
| | - Eva González-Suárez
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Avinguda de la Gran Via, 199-203, L'Hospitalet de Llobregat, Barcelona, Spain.
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30
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Ladányi A, Tímár J. Immunologic and immunogenomic aspects of tumor progression. Semin Cancer Biol 2019; 60:249-261. [PMID: 31419526 DOI: 10.1016/j.semcancer.2019.08.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/12/2019] [Accepted: 08/12/2019] [Indexed: 12/11/2022]
Abstract
Tumor progression to metastatic disease is characterized by continuous genetic alterations due to instability of the genome. Immune sensitivity was found to be linked to tumor mutational burden (TMB) and the resulting amount of neoantigens. However, APOBEC activity resulting in increase in TMB causes immune evasion. On the other hand, clonal or acquired genetic loss of HLA class I also hampers immune sensitivity of tumors. Rare amplification of the PD-L1 gene in cancers may render them sensitive to immune checkpoint inhibitors but involvement of broader regions of chromosome 9p may ultimately lead again to immune evasion due to inactivation of the IFN-γ signaling pathway. Such genetic changes may occur not only in the primary tumor but at any phase of progression: in lymphatic as well as in visceral metastases. Accordingly, it is rational to monitor these changes continuously during disease progression similar to target therapies. Moreover, beside temporal variability, genomic features of tumors such as mutation profiles, as well as the tumor immune microenvironment also show considerable inter- and intratumoral spatial heterogeneity, suggesting the necessity of multiple sampling in biomarker studies.
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Affiliation(s)
| | - József Tímár
- 2nd Department of Pathology, Semmelweis University, Budapest, Hungary.
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31
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Nieminuszczy J, Broderick R, Bellani MA, Smethurst E, Schwab RA, Cherdyntseva V, Evmorfopoulou T, Lin YL, Minczuk M, Pasero P, Gagos S, Seidman MM, Niedzwiedz W. EXD2 Protects Stressed Replication Forks and Is Required for Cell Viability in the Absence of BRCA1/2. Mol Cell 2019; 75:605-619.e6. [PMID: 31255466 PMCID: PMC6695479 DOI: 10.1016/j.molcel.2019.05.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 04/15/2019] [Accepted: 05/17/2019] [Indexed: 12/15/2022]
Abstract
Accurate DNA replication is essential to preserve genomic integrity and prevent chromosomal instability-associated diseases including cancer. Key to this process is the cells' ability to stabilize and restart stalled replication forks. Here, we show that the EXD2 nuclease is essential to this process. EXD2 recruitment to stressed forks suppresses their degradation by restraining excessive fork regression. Accordingly, EXD2 deficiency leads to fork collapse, hypersensitivity to replication inhibitors, and genomic instability. Impeding fork regression by inactivation of SMARCAL1 or removal of RECQ1's inhibition in EXD2-/- cells restores efficient fork restart and genome stability. Moreover, purified EXD2 efficiently processes substrates mimicking regressed forks. Thus, this work identifies a mechanism underpinned by EXD2's nuclease activity, by which cells balance fork regression with fork restoration to maintain genome stability. Interestingly, from a clinical perspective, we discover that EXD2's depletion is synthetic lethal with mutations in BRCA1/2, implying a non-redundant role in replication fork protection.
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Affiliation(s)
| | | | - Marina A Bellani
- Laboratory of Molecular Gerontology, National Institute on Aging, Baltimore, MD, USA
| | | | | | - Veronica Cherdyntseva
- Laboratory of Genetics, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Theodora Evmorfopoulou
- Laboratory of Genetics, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Yea-Lih Lin
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Montpellier, France
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Philippe Pasero
- Institut de Génétique Humaine, CNRS, Université de Montpellier, Montpellier, France
| | - Sarantis Gagos
- Laboratory of Genetics, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Michael M Seidman
- Laboratory of Molecular Gerontology, National Institute on Aging, Baltimore, MD, USA
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32
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Pellestor F, Gatinois V. Chromoanasynthesis: another way for the formation of complex chromosomal abnormalities in human reproduction. Hum Reprod 2019; 33:1381-1387. [PMID: 30325427 DOI: 10.1093/humrep/dey231] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Indexed: 12/24/2022] Open
Abstract
Chromoanasynthesis has been described as a novel cause of massive constitutional chromosomal rearrangements. Based on DNA replication machinery defects, chromoanasynthesis is characterized by the presence of chromosomal duplications and triplications locally clustered on one single chromosome, or a few chromosomes, associated with various other types of structural rearrangements. Two distinct mechanisms have been described for the formation of these chaotic genomic disorders, i.e. the fork stalling and template switching and the microhomology-mediated break-induced replication. Micronucleus-based processes have been evidenced as a causative mechanism, thus, highlighting the close connection between segregation errors and structural rearrangements. Accumulating data indicate that chromoanasynthesis is operating in human germline cells and during early embryonic development. The development of new tools for quantifying chromoanasynthesis events should provide further insight into the impact of this catastrophic cellular phenomenon in human reproduction.
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Affiliation(s)
- Franck Pellestor
- Unit of Chromosomal Genetics, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, Montpellier, France
| | - Vincent Gatinois
- Unit of Chromosomal Genetics, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHU, Montpellier, France
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Crickard JB, Greene EC. Helicase Mechanisms During Homologous Recombination in Saccharomyces cerevisiae. Annu Rev Biophys 2019; 48:255-273. [PMID: 30857400 DOI: 10.1146/annurev-biophys-052118-115418] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Helicases are enzymes that move, manage, and manipulate nucleic acids. They can be subdivided into six super families and are required for all aspects of nucleic acid metabolism. In general, all helicases function by converting the chemical energy stored in the bond between the gamma and beta phosphates of adenosine triphosphate into mechanical work, which results in the unidirectional movement of the helicase protein along one strand of a nucleic acid. The results of this translocation activity can range from separation of strands within duplex nucleic acids to the physical remodeling or removal of nucleoprotein complexes. In this review, we focus on describing key helicases from the model organism Saccharomyces cerevisiae that contribute to the regulation of homologous recombination, which is an essential DNA repair pathway for fixing damaged chromosomes.
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Affiliation(s)
- J Brooks Crickard
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; ,
| | - Eric C Greene
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; ,
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Regulatory control of Sgs1 and Dna2 during eukaryotic DNA end resection. Proc Natl Acad Sci U S A 2019; 116:6091-6100. [PMID: 30850524 DOI: 10.1073/pnas.1819276116] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In the repair of DNA double-strand breaks by homologous recombination, the DNA break ends must first be processed into 3' single-strand DNA overhangs. In budding yeast, end processing requires the helicase Sgs1 (BLM in humans), the nuclease/helicase Dna2, Top3-Rmi1, and replication protein A (RPA). Here, we use single-molecule imaging to visualize Sgs1-dependent end processing in real-time. We show that Sgs1 is recruited to DNA ends through Top3-Rmi1-dependent or -independent means, and in both cases Sgs1 is maintained in an immoble state at the DNA ends. Importantly, the addition of Dna2 triggers processive Sgs1 translocation, but DNA resection only occurs when RPA is also present. We also demonstrate that the Sgs1-Dna2-Top3-Rmi1-RPA ensemble can efficiently disrupt nucleosomes, and that Sgs1 itself possesses nucleosome remodeling activity. Together, these results shed light on the regulatory interplay among conserved protein factors that mediate the nucleolytic processing of DNA ends in preparation for homologous recombination-mediated chromosome damage repair.
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Pellestor F. Chromoanagenesis: cataclysms behind complex chromosomal rearrangements. Mol Cytogenet 2019; 12:6. [PMID: 30805029 PMCID: PMC6371609 DOI: 10.1186/s13039-019-0415-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 01/17/2019] [Indexed: 12/21/2022] Open
Abstract
Background During the last decade, genome sequencing projects in cancer genomes as well as in patients with congenital diseases and healthy individuals have led to the identification of new types of massive chromosomal rearrangements arising during single chaotic cellular events. These unanticipated catastrophic phenomenon are termed chromothripsis, chromoanasynthesis and chromoplexis., and are grouped under the name of “chromoanagenesis”. Results For each process, several specific features have been described, allowing each phenomenon to be distinguished from each other and to understand its mechanism of formation and to better understand its aetiology. Thus, chromothripsis derives from chromosome shattering followed by the random restitching of chromosomal fragments with low copy-number change whereas chromoanasynthesis results from erroneous DNA replication of a chromosome through serial fork stalling and template switching with variable copy-number gains, and chromoplexy refers to the occurrence of multiple inter-and intra-chromosomal translocations and deletions with little or no copy-number alterations in prostate cancer. Cumulating data and experimental models have shown that chromothripsis and chromoanasynthesis may essentially result from lagging chromosome encapsulated in micronuclei or telomere attrition and end-to-end telomere fusion. Conclusion The concept of chromanagenesis has provided new insight into the aetiology of complex structural rearrangements, the connection between defective cell cycle progression and genomic instability, and the complexity of cancer evolution. Increasing reported chromoanagenesis events suggest that these chaotic mechanisms are probably much more frequent than anticipated.
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Affiliation(s)
- Franck Pellestor
- Unit of Chromosomal Genetics, Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier CHRU, 371, avenue du Doyen Gaston Giraud, 34295 Montpellier cedex 5, France.,INSERM 1183 Unit «Genome and Stem Cell Plasticity in Development and Aging », Institute of Regenerative Medicine and Biotherapies, St Eloi Hospital, Montpellier, France
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Witt DA, Donson AM, Amani V, Moreira DC, Sanford B, Hoffman LM, Handler MH, Mulcahy Levy JM, Jones KL, Nellan A, Foreman NK, Griesinger AM. Specific expression of PD-L1 in RELA-fusion supratentorial ependymoma: Implications for PD-1-targeted therapy. Pediatr Blood Cancer 2018; 65:e26960. [PMID: 29350470 PMCID: PMC5867234 DOI: 10.1002/pbc.26960] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/28/2017] [Accepted: 12/11/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND A desperate need for novel therapies in pediatric ependymoma (EPN) exists, as chemotherapy remains ineffective and radiotherapy often fails. EPN have significant infiltration of immune cells, which correlates with outcome. Immune checkpoint inhibitors provide an avenue for new treatments. This study characterizes tumor-infiltrating immune cells in EPN and aims at predicting candidates for clinical trials using checkpoint inhibitors targeting PD-L1/PD-1 (programmed death ligand 1/programmed death 1). METHODS The transcriptomic profiles of the primary study cohort of EPN and other pediatric brain tumors were interrogated to identify PD-L1 expression levels. Transcriptomic findings were validated using the western blotting, immunohistochemistry and flow cytometry. RESULTS We evaluated PD-L1 mRNA expression across four intracranial subtypes of EPN in two independent cohorts and found supratentorial RELA fusion (ST-RELA) tumors to have significantly higher levels. There was a correlation between high gene expression and protein PD-L1 levels in ST-RELA tumors by both the western blot and immunohistochemisty. The investigation of EPN cell populations revealed PD-L1 was expressed on both tumor and myeloid cells in ST-RELA. Other subtypes had little PD-L1 in either tumor or myeloid cell compartments. Lastly, we measured PD-1 levels on tumor-infiltrating T cells and found ST-RELA tumors express PD-1 in both CD4 and CD8 T cells. A functional T-cell exhaustion assay found ST-RELA T cells to be exhausted and unable to secrete IFNγ on stimulation. CONCLUSIONS These findings in ST-RELA suggest tumor evasion and immunsuppression due to PD-L1/PD-1-mediated T-cell exhaustion. Trials of checkpoint inhibitors in EPN should be enriched for ST-RELA tumors.
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Affiliation(s)
- Davis A. Witt
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado,Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children’s Hospital Colorado, Aurora, Colorado
| | - Andrew M. Donson
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado,Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children’s Hospital Colorado, Aurora, Colorado
| | - Vladimir Amani
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado,Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children’s Hospital Colorado, Aurora, Colorado
| | - Daniel C. Moreira
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado,Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children’s Hospital Colorado, Aurora, Colorado
| | - Bridget Sanford
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado
| | - Lindsey M. Hoffman
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado,Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children’s Hospital Colorado, Aurora, Colorado
| | - Michael H. Handler
- Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children’s Hospital Colorado, Aurora, Colorado,Department of Neurosurgery, University of Colorado Denver
| | - Jean M. Mulcahy Levy
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado,Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children’s Hospital Colorado, Aurora, Colorado
| | - Kenneth L. Jones
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado
| | - Anandani Nellan
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado,Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children’s Hospital Colorado, Aurora, Colorado
| | - Nicholas K. Foreman
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado,Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children’s Hospital Colorado, Aurora, Colorado
| | - Andrea M. Griesinger
- Department of Pediatrics, University of Colorado Denver, Aurora, Colorado,Morgan Adams Foundation Pediatric Brain Tumor Research Program, Children’s Hospital Colorado, Aurora, Colorado
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Knijnenburg TA, Wang L, Zimmermann MT, Chambwe N, Gao GF, Cherniack AD, Fan H, Shen H, Way GP, Greene CS, Liu Y, Akbani R, Feng B, Donehower LA, Miller C, Shen Y, Karimi M, Chen H, Kim P, Jia P, Shinbrot E, Zhang S, Liu J, Hu H, Bailey MH, Yau C, Wolf D, Zhao Z, Weinstein JN, Li L, Ding L, Mills GB, Laird PW, Wheeler DA, Shmulevich I, Monnat RJ, Xiao Y, Wang C. Genomic and Molecular Landscape of DNA Damage Repair Deficiency across The Cancer Genome Atlas. Cell Rep 2018; 23:239-254.e6. [PMID: 29617664 PMCID: PMC5961503 DOI: 10.1016/j.celrep.2018.03.076] [Citation(s) in RCA: 675] [Impact Index Per Article: 112.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 03/07/2018] [Accepted: 03/19/2018] [Indexed: 12/20/2022] Open
Abstract
DNA damage repair (DDR) pathways modulate cancer risk, progression, and therapeutic response. We systematically analyzed somatic alterations to provide a comprehensive view of DDR deficiency across 33 cancer types. Mutations with accompanying loss of heterozygosity were observed in over 1/3 of DDR genes, including TP53 and BRCA1/2. Other prevalent alterations included epigenetic silencing of the direct repair genes EXO5, MGMT, and ALKBH3 in ∼20% of samples. Homologous recombination deficiency (HRD) was present at varying frequency in many cancer types, most notably ovarian cancer. However, in contrast to ovarian cancer, HRD was associated with worse outcomes in several other cancers. Protein structure-based analyses allowed us to predict functional consequences of rare, recurrent DDR mutations. A new machine-learning-based classifier developed from gene expression data allowed us to identify alterations that phenocopy deleterious TP53 mutations. These frequent DDR gene alterations in many human cancers have functional consequences that may determine cancer progression and guide therapy.
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Affiliation(s)
| | - Linghua Wang
- Department of Genomic Medicine, Division of Cancer Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Michael T Zimmermann
- Genomic Sciences and Precision Medicine Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226-0509, USA; Department of Health Sciences Research, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | | | - Galen F Gao
- The Eli and Edythe L. Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02142, USA
| | - Andrew D Cherniack
- The Eli and Edythe L. Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA 02142, USA
| | - Huihui Fan
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Hui Shen
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Gregory P Way
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19103, USA
| | - Casey S Greene
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19103, USA
| | - Yuexin Liu
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Rehan Akbani
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Bin Feng
- TESARO Inc., Waltham, MA 02451, USA
| | - Lawrence A Donehower
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Chase Miller
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yang Shen
- Department of Electrical and Computer Engineering, 3128 TAMU, Texas A&M University, College Station, TX 77843, USA
| | - Mostafa Karimi
- Department of Electrical and Computer Engineering, 3128 TAMU, Texas A&M University, College Station, TX 77843, USA
| | - Haoran Chen
- Department of Electrical and Computer Engineering, 3128 TAMU, Texas A&M University, College Station, TX 77843, USA
| | - Pora Kim
- Center for Precision Health, School of Biomedical Informatics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Peilin Jia
- Center for Precision Health, School of Biomedical Informatics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Eve Shinbrot
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Shaojun Zhang
- Department of Genomic Medicine, Division of Cancer Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA
| | - Jianfang Liu
- Chan Soon-Shiong Institute of Molecular Medicine at Windber, Windber, PA 15963, USA
| | - Hai Hu
- Chan Soon-Shiong Institute of Molecular Medicine at Windber, Windber, PA 15963, USA
| | - Matthew H Bailey
- Division of Oncology, Department of Medicine, Washington University, St. Louis, MO 63110, USA; McDonnell Genome Institute, Washington University, St. Louis, MO 63110, USA
| | - Christina Yau
- University of California, San Francisco, San Francisco, CA 94115, USA; Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Denise Wolf
- University of California, San Francisco, San Francisco, CA 94115, USA
| | - Zhongming Zhao
- Center for Precision Health, School of Biomedical Informatics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - John N Weinstein
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Lei Li
- Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer, Houston, TX 77030, USA
| | - Li Ding
- Division of Oncology, Department of Medicine, Washington University, St. Louis, MO 63110, USA; McDonnell Genome Institute, Washington University, St. Louis, MO 63110, USA; Department of Genetics, Washington University, St. Louis, MO 63110, USA; Siteman Cancer Center, Washington University, St. Louis, MO 63110, USA
| | - Gordon B Mills
- Department of Systems Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Peter W Laird
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - David A Wheeler
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Raymond J Monnat
- Departments of Pathology & Genome Sciences, University of Washington, Seattle, WA 98195-7705, USA.
| | | | - Chen Wang
- Department of Health Sciences Research, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA; Department of Obstetrics and Gynecology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
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Machiela MJ, Jessop L, Zhou W, Yeager M, Chanock SJ. Characterization of breakpoint regions of large structural autosomal mosaic events. Hum Mol Genet 2018; 26:4388-4394. [PMID: 28973384 DOI: 10.1093/hmg/ddx324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 08/14/2017] [Indexed: 01/10/2023] Open
Abstract
Recent studies have reported a higher than anticipated frequency of large clonal autosomal mosaic events >2 Mb in size in the aging population. Mosaic events are detected from analyses of intensity parameters of linear stretches with deviations in heterozygous probes of single nucleotide polymorphism microarrays. The non-random distribution of detected mosaic events throughout the genome suggests common mechanisms could influence the formation of mosaic events. Here we use publicly available data tracks from the University of California Santa Cruz Genome Browser to investigate the genomic characteristics of the regions at the terminal ends of two frequent types of large structural mosaic events: telomeric neutral events and interstitial losses. We observed breakpoints are more likely to occur in regions enriched for open chromatin, increased gene density, elevated meiotic recombination rates and in the proximity of repetitive elements. These observations suggest that detected mosaic event breakpoints are preferentially recovered in genomic regions that are observed to be active and thus more accessible to environmental exposures and events related to gene transcription. We propose that errors in DNA repair pathways, such as non-homologous end joining and homologous recombination, may be important cellular mechanisms that lead to the formation of large structural mosaic events such as interstitial losses and copy neutral events that include telomeres. Further studies using next generation sequencing technologies should be instrumental in mapping the specific junctions of mosaic events to the nucleotide and provide insights into the molecular mechanisms responsible for clonal somatic structural events.
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Affiliation(s)
- Mitchell J Machiela
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - Lea Jessop
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - Weiyin Zhou
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA.,Cancer Genomics Research Laboratory, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD, USA
| | - Meredith Yeager
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA.,Cancer Genomics Research Laboratory, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD, USA
| | - Stephen J Chanock
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
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Abstract
Targeting cancers dependent on DNA polymerase θ has considerable clinical potential
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Affiliation(s)
- Geoff S Higgins
- Cancer Research UK-Medical Research Council Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, UK.
| | - Simon J Boulton
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
- Artios Pharma Limited, Maia, Babraham Research Campus, Cambridge CB22 3AT, UK
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Chen CC, Feng W, Lim PX, Kass EM, Jasin M. Homology-Directed Repair and the Role of BRCA1, BRCA2, and Related Proteins in Genome Integrity and Cancer. ANNUAL REVIEW OF CANCER BIOLOGY 2018; 2:313-336. [PMID: 30345412 PMCID: PMC6193498 DOI: 10.1146/annurev-cancerbio-030617-050502] [Citation(s) in RCA: 190] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Germ-line and somatic mutations in genes that promote homology-directed repair (HDR), especially BRCA1 and BRCA2, are frequently observed in several cancers, in particular, breast and ovary but also prostate and other cancers. HDR is critical for the error-free repair of DNA double-strand breaks and other lesions, and HDR factors also protect stalled replication forks. As a result, loss of BRCA1 or BRCA2 poses significant risks to genome integrity, leading not only to cancer predisposition but also to sensitivity to DNA-damaging agents, affecting therapeutic approaches. Here we review recent advances in our understanding of BRCA1 and BRCA2, including how they genetically interact with other repair factors, how they protect stalled replication forks, how they affect the response to aldehydes, and how loss of their functions links to mutation signatures. Importantly, given the recent advances with poly(ADP-ribose) polymerase inhibitors (PARPi) for the treatment of HDR-deficient tumors, we discuss mechanisms by which BRCA-deficient tumors acquire resistance to PARPi and other agents.
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Affiliation(s)
- Chun-Chin Chen
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY 10065
| | - Weiran Feng
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Pei Xin Lim
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Elizabeth M Kass
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065
- Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY 10065
- Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065
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Vlajnic T, Savic S, Barascud A, Baschiera B, Bihl M, Grilli B, Herzog M, Rebetez J, Bubendorf L. Detection of ROS1-positive non-small cell lung cancer on cytological specimens using immunocytochemistry. Cancer Cytopathol 2018; 126:421-429. [DOI: 10.1002/cncy.21983] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/26/2018] [Accepted: 01/26/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Tatjana Vlajnic
- Institute of Pathology; University Hospital Basel; Basel Switzerland
| | - Spasenija Savic
- Institute of Pathology; University Hospital Basel; Basel Switzerland
| | - Audrey Barascud
- Institute of Pathology; University Hospital Basel; Basel Switzerland
| | - Betty Baschiera
- Institute of Pathology; University Hospital Basel; Basel Switzerland
| | - Michel Bihl
- Institute of Pathology; University Hospital Basel; Basel Switzerland
| | - Bruno Grilli
- Institute of Pathology; University Hospital Basel; Basel Switzerland
| | - Michelle Herzog
- Institute of Pathology; University Hospital Basel; Basel Switzerland
| | - Julien Rebetez
- Institute of Pathology; University Hospital Basel; Basel Switzerland
| | - Lukas Bubendorf
- Institute of Pathology; University Hospital Basel; Basel Switzerland
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De Tullio L, Kaniecki K, Greene EC. Single-Stranded DNA Curtains for Studying the Srs2 Helicase Using Total Internal Reflection Fluorescence Microscopy. Methods Enzymol 2018; 600:407-437. [PMID: 29458768 DOI: 10.1016/bs.mie.2017.12.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Helicases are crucial participants in many types of DNA repair reactions, including homologous recombination. The properties of these enzymes can be assayed by traditional bulk biochemical analysis; however, these types of assays cannot directly access some types of information. In particular, bulk biochemical assays cannot readily access information that may be obscured in population averages. Single-molecule assays offer the potential advantage of being able to visualize the molecules in question in real time, thus providing direct access to questions relating to translocation velocity, processivity, and insights into how helicases may behave on different types of substrates. Here, we describe the use of single-stranded DNA (ssDNA) curtains as an assay for directly viewing the behavior of the Saccharomyces cerevisiae Srs2 helicase on single molecules of ssDNA. When used with total internal reflection fluorescence microscopy, these methods can be used to track the binding and movements of individual helicase complexes, and allow new insights into helicase behaviors at the single-molecule level.
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Vidotto T, Tiezzi DG, Squire JA. Distinct subtypes of genomic PTEN deletion size influence the landscape of aneuploidy and outcome in prostate cancer. Mol Cytogenet 2018; 11:1. [PMID: 29308088 PMCID: PMC5753467 DOI: 10.1186/s13039-017-0348-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 12/01/2017] [Indexed: 12/16/2022] Open
Abstract
Background Inactivation of the PTEN tumor suppressor gene by deletion occurs in 20-30% of prostate cancer tumors and loss strongly correlates with a worse outcome. PTEN loss of function not only leads to activation of the PI3K/AKT pathway, but is also thought to affect genome stability and increase levels of tumor aneuploidy. We performed an in silico integrative genomic and transcriptomic analysis of 491 TCGA prostate cancer tumors. These data were used to map the genomic sizes of PTEN gene deletions and to characterize levels of instability and patterns of aneuploidy acquisition. Results PTEN homozygous deletions had a significant increase in aneuploidy compared to PTEN tumors without an apparent deletion, and hemizygous deletions showed an intermediate aneuploidy profile. A supervised clustering of somatic copy number alterations (SCNA) demonstrated that the size of PTEN deletions was not random, but comprised five distinct subtypes: (1) "Small Interstitial" (70 bp-789Kb); (2) "Large Interstitial" (1-7 MB); (3) "Large Proximal" (3-65 MB); (4) "Large Terminal" (8-64 MB), and (5) "Extensive" (71-132 MB). Many of the deleted fragments in each subtype were flanked by low copy repetitive (LCR) sequences. SCNAs such as gain at 3q21.1-3q29 and deletions at 8p, RB1, TP53 and TMPRSS2-ERG were variably present in all subtypes. Other SCNAs appeared to be recurrent in some deletion subtypes, but absent from others. To determine how the aneuploidy influenced global levels of gene expression, we performed a comparative transcriptome analysis. One deletion subtype (Large Interstitial) was characterized by gene expression changes associated with angiogenesis and cell adhesion, structure, and metabolism. Logistic regression demonstrated that this deletion subtype was associated with a high Gleason score (HR = 2.386; 95% C.I. 1.245-4.572), extraprostatic extension (HR = 2.423, 95% C.I. 1.157-5.075), and metastasis (HR = 7.135; 95% C.I. 1.540-33.044). Univariate and multivariate Cox Regression showed that presence of this deletion subtype was also strongly predictive of disease recurrence. Conclusions Our findings indicate that genomic deletions of PTEN fall into five different size distributions, with breakpoints that often occur close LCR regions, and that each subtype is associated with a characteristic aneuploidy signature. The Large Interstitial deletion had a distinct gene expression signature that was related to cancer progression and was also predictive of a worse prognosis.
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Affiliation(s)
- Thiago Vidotto
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Daniel Guimarães Tiezzi
- Deparment of Gynecology and Obstetrics, Clinical Hospital of Ribeirão Preto, Ribeirão Preto, Brazil
| | - Jeremy A Squire
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.,Department of Pathology and Legal Medicine, Ribeirão Preto Medical School, University of São Paulo, 3900 Bandeirantes Avenue, Monte Alegre, Ribeirão Preto, São Paulo 14040-900 Brazil.,Department of Pathology and Molecular Medicine, Queen's University, Kingston, Canada
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Böttcher R, Kweldam CF, Livingstone J, Lalonde E, Yamaguchi TN, Huang V, Yousif F, Fraser M, Bristow RG, van der Kwast T, Boutros PC, Jenster G, van Leenders GJLH. Cribriform and intraductal prostate cancer are associated with increased genomic instability and distinct genomic alterations. BMC Cancer 2018; 18:8. [PMID: 29295717 PMCID: PMC5751811 DOI: 10.1186/s12885-017-3976-z] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 12/21/2017] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Invasive cribriform and intraductal carcinoma (CR/IDC) is associated with adverse outcome of prostate cancer patients. The aim of this study was to determine the molecular aberrations associated with CR/IDC in primary prostate cancer, focusing on genomic instability and somatic copy number alterations (CNA). METHODS Whole-slide images of The Cancer Genome Atlas Project (TCGA, N = 260) and the Canadian Prostate Cancer Genome Network (CPC-GENE, N = 199) radical prostatectomy datasets were reviewed for Gleason score (GS) and presence of CR/IDC. Genomic instability was assessed by calculating the percentage of genome altered (PGA). Somatic copy number alterations (CNA) were determined using Fisher-Boschloo tests and logistic regression. Primary analysis were performed on TCGA (N = 260) as discovery and CPC-GENE (N = 199) as validation set. RESULTS CR/IDC growth was present in 80/260 (31%) TCGA and 76/199 (38%) CPC-GENE cases. Patients with CR/IDC and ≥ GS 7 had significantly higher PGA than men without this pattern in both TCGA (2.2 fold; p = 0.0003) and CPC-GENE (1.7 fold; p = 0.004) cohorts. CR/IDC growth was associated with deletions of 8p, 16q, 10q23, 13q22, 17p13, 21q22, and amplification of 8q24. CNAs comprised a total of 1299 gene deletions and 369 amplifications in the TCGA dataset, of which 474 and 328 events were independently validated, respectively. Several of the affected genes were known to be associated with aggressive prostate cancer such as loss of PTEN, CDH1, BCAR1 and gain of MYC. Point mutations in TP53, SPOP and FOXA1were also associated with CR/IDC, but occurred less frequently than CNAs. CONCLUSIONS CR/IDC growth is associated with increased genomic instability clustering to genetic regions involved in aggressive prostate cancer. Therefore, CR/IDC is a pathologic substrate for progressive molecular tumour derangement.
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Affiliation(s)
- René Böttcher
- Department of Urology, Erasmus MC, Rotterdam, the Netherlands
| | - Charlotte F. Kweldam
- Department of Pathology, Erasmus University Medical Center, Josephine Nefkens Institute building, Be-222, P.O. Box 2040, Rotterdam, 3000 CA The Netherlands
| | - Julie Livingstone
- Informatics & Biocomputing Program, Ontario Institute for Cancer Research, Toronto, ON Canada
| | - Emilie Lalonde
- Informatics & Biocomputing Program, Ontario Institute for Cancer Research, Toronto, ON Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON Canada
| | - Takafumi N. Yamaguchi
- Informatics & Biocomputing Program, Ontario Institute for Cancer Research, Toronto, ON Canada
| | - Vincent Huang
- Informatics & Biocomputing Program, Ontario Institute for Cancer Research, Toronto, ON Canada
| | - Fouad Yousif
- Informatics & Biocomputing Program, Ontario Institute for Cancer Research, Toronto, ON Canada
| | - Michael Fraser
- Ontario Cancer Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, ON Canada
| | - Robert G. Bristow
- Department of Medical Biophysics, University of Toronto, Toronto, ON Canada
- Ontario Cancer Institute, Princess Margaret Cancer Centre, University Health Network, Toronto, ON Canada
- Department of Radiation Oncology, University of Toronto, Toronto, ON Canada
| | - Theodorus van der Kwast
- Department of Pathology and Laboratory Medicine, Toronto General Hospital, University Health Network, Toronto, ON Canada
| | - Paul C. Boutros
- Informatics & Biocomputing Program, Ontario Institute for Cancer Research, Toronto, ON Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON Canada
| | - Guido Jenster
- Department of Urology, Erasmus MC, Rotterdam, the Netherlands
| | - Geert J. L. H. van Leenders
- Department of Pathology, Erasmus University Medical Center, Josephine Nefkens Institute building, Be-222, P.O. Box 2040, Rotterdam, 3000 CA The Netherlands
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Abstract
Genetic recombination occurs in all organisms and is vital for genome stability. Indeed, in humans, aberrant recombination can lead to diseases such as cancer. Our understanding of homologous recombination is built upon more than a century of scientific inquiry, but achieving a more complete picture using ensemble biochemical and genetic approaches is hampered by population heterogeneity and transient recombination intermediates. Recent advances in single-molecule and super-resolution microscopy methods help to overcome these limitations and have led to new and refined insights into recombination mechanisms, including a detailed understanding of DNA helicase function and synaptonemal complex structure. The ability to view cellular processes at single-molecule resolution promises to transform our understanding of recombination and related processes.
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Shapiro JA. Living Organisms Author Their Read-Write Genomes in Evolution. BIOLOGY 2017; 6:E42. [PMID: 29211049 PMCID: PMC5745447 DOI: 10.3390/biology6040042] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/17/2017] [Accepted: 11/28/2017] [Indexed: 12/18/2022]
Abstract
Evolutionary variations generating phenotypic adaptations and novel taxa resulted from complex cellular activities altering genome content and expression: (i) Symbiogenetic cell mergers producing the mitochondrion-bearing ancestor of eukaryotes and chloroplast-bearing ancestors of photosynthetic eukaryotes; (ii) interspecific hybridizations and genome doublings generating new species and adaptive radiations of higher plants and animals; and, (iii) interspecific horizontal DNA transfer encoding virtually all of the cellular functions between organisms and their viruses in all domains of life. Consequently, assuming that evolutionary processes occur in isolated genomes of individual species has become an unrealistic abstraction. Adaptive variations also involved natural genetic engineering of mobile DNA elements to rewire regulatory networks. In the most highly evolved organisms, biological complexity scales with "non-coding" DNA content more closely than with protein-coding capacity. Coincidentally, we have learned how so-called "non-coding" RNAs that are rich in repetitive mobile DNA sequences are key regulators of complex phenotypes. Both biotic and abiotic ecological challenges serve as triggers for episodes of elevated genome change. The intersections of cell activities, biosphere interactions, horizontal DNA transfers, and non-random Read-Write genome modifications by natural genetic engineering provide a rich molecular and biological foundation for understanding how ecological disruptions can stimulate productive, often abrupt, evolutionary transformations.
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Affiliation(s)
- James A Shapiro
- Department of Biochemistry and Molecular Biology, University of Chicago GCIS W123B, 979 E. 57th Street, Chicago, IL 60637, USA.
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Ruff P, Donnianni RA, Glancy E, Oh J, Symington LS. RPA Stabilization of Single-Stranded DNA Is Critical for Break-Induced Replication. Cell Rep 2017; 17:3359-3368. [PMID: 28009302 DOI: 10.1016/j.celrep.2016.12.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/28/2016] [Accepted: 11/30/2016] [Indexed: 01/12/2023] Open
Abstract
DNA double-strand breaks (DSBs) are cytotoxic lesions that must be accurately repaired to maintain genome stability. Replication protein A (RPA) plays an important role in homology-dependent repair of DSBs by protecting the single-stranded DNA (ssDNA) intermediates formed by end resection and by facilitating Rad51 loading. We found that hypomorphic mutants of RFA1 that support intra-chromosomal homologous recombination are profoundly defective for repair processes involving long tracts of DNA synthesis, in particular break-induced replication (BIR). The BIR defects of the rfa1 mutants could be partially suppressed by eliminating the Sgs1-Dna2 resection pathway, suggesting that Dna2 nuclease attacks the ssDNA formed during end resection when not fully protected by RPA. Overexpression of Rad51 was also found to suppress the rfa1 BIR defects. We suggest that Rad51 binding to the ssDNA formed by excessive end resection and during D-loop migration can partially compensate for dysfunctional RPA.
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Affiliation(s)
- Patrick Ruff
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Roberto A Donnianni
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Eleanor Glancy
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Julyun Oh
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Lorraine S Symington
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA.
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Pathways and Mechanisms that Prevent Genome Instability in Saccharomyces cerevisiae. Genetics 2017; 206:1187-1225. [PMID: 28684602 PMCID: PMC5500125 DOI: 10.1534/genetics.112.145805] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 04/26/2017] [Indexed: 12/13/2022] Open
Abstract
Genome rearrangements result in mutations that underlie many human diseases, and ongoing genome instability likely contributes to the development of many cancers. The tools for studying genome instability in mammalian cells are limited, whereas model organisms such as Saccharomyces cerevisiae are more amenable to these studies. Here, we discuss the many genetic assays developed to measure the rate of occurrence of Gross Chromosomal Rearrangements (called GCRs) in S. cerevisiae. These genetic assays have been used to identify many types of GCRs, including translocations, interstitial deletions, and broken chromosomes healed by de novo telomere addition, and have identified genes that act in the suppression and formation of GCRs. Insights from these studies have contributed to the understanding of pathways and mechanisms that suppress genome instability and how these pathways cooperate with each other. Integrated models for the formation and suppression of GCRs are discussed.
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Dungrawala H, Bhat KP, Le Meur R, Chazin WJ, Ding X, Sharan SK, Wessel SR, Sathe AA, Zhao R, Cortez D. RADX Promotes Genome Stability and Modulates Chemosensitivity by Regulating RAD51 at Replication Forks. Mol Cell 2017; 67:374-386.e5. [PMID: 28735897 PMCID: PMC5548441 DOI: 10.1016/j.molcel.2017.06.023] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/31/2017] [Accepted: 06/19/2017] [Indexed: 01/31/2023]
Abstract
RAD51 promotes homology-directed repair (HDR), replication fork reversal, and stalled fork protection. Defects in these functions cause genomic instability and tumorigenesis but also generate hypersensitivity to cancer therapeutics. Here we describe the identification of RADX as an RPA-like, single-strand DNA binding protein. RADX is recruited to replication forks, where it prevents fork collapse by regulating RAD51. When RADX is inactivated, excessive RAD51 activity slows replication elongation and causes double-strand breaks. In cancer cells lacking BRCA2, RADX deletion restores fork protection without restoring HDR. Furthermore, RADX inactivation confers chemotherapy and PARP inhibitor resistance to cancer cells with reduced BRCA2/RAD51 pathway function. By antagonizing RAD51 at forks, RADX allows cells to maintain a high capacity for HDR while ensuring that replication functions of RAD51 are properly regulated. Thus, RADX is essential to achieve the proper balance of RAD51 activity to maintain genome stability.
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Affiliation(s)
- Huzefa Dungrawala
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Kamakoti P Bhat
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Rémy Le Meur
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Walter J Chazin
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - Xia Ding
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
| | - Shyam K Sharan
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
| | - Sarah R Wessel
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Aditya A Sathe
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Runxiang Zhao
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - David Cortez
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA.
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