51
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ATR Signaling Uncouples the Role of RAD51 Paralogs in Homologous Recombination and Replication Stress Response. Cell Rep 2019; 29:551-559.e4. [DOI: 10.1016/j.celrep.2019.09.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 07/31/2019] [Accepted: 09/04/2019] [Indexed: 01/09/2023] Open
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52
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Hirth G, Svensson CM, Böttcher K, Ullrich S, Figge MT, Jungnickel B. Regulation of the Germinal Center Reaction and Somatic Hypermutation Dynamics by Homologous Recombination. THE JOURNAL OF IMMUNOLOGY 2019; 203:1493-1501. [DOI: 10.4049/jimmunol.1900483] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 07/04/2019] [Indexed: 01/09/2023]
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53
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Jalan M, Olsen KS, Powell SN. Emerging Roles of RAD52 in Genome Maintenance. Cancers (Basel) 2019; 11:E1038. [PMID: 31340507 PMCID: PMC6679097 DOI: 10.3390/cancers11071038] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/17/2019] [Accepted: 07/18/2019] [Indexed: 12/22/2022] Open
Abstract
The maintenance of genome integrity is critical for cell survival. Homologous recombination (HR) is considered the major error-free repair pathway in combatting endogenously generated double-stranded lesions in DNA. Nevertheless, a number of alternative repair pathways have been described as protectors of genome stability, especially in HR-deficient cells. One of the factors that appears to have a role in many of these pathways is human RAD52, a DNA repair protein that was previously considered to be dispensable due to a lack of an observable phenotype in knock-out mice. In later studies, RAD52 deficiency has been shown to be synthetically lethal with defects in BRCA genes, making RAD52 an attractive therapeutic target, particularly in the context of BRCA-deficient tumors.
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Affiliation(s)
- Manisha Jalan
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Kyrie S Olsen
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Simon N Powell
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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54
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Quan Y, Lin J, Deng B. The response of human mesenchymal stem cells to internal exposure to tritium β-rays. JOURNAL OF RADIATION RESEARCH 2019; 60:476-482. [PMID: 31165153 PMCID: PMC6640910 DOI: 10.1093/jrr/rrz037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 02/04/2019] [Indexed: 05/04/2023]
Abstract
There is no doubt that estimating the exposure risk of external and internal low-dose radiation is an imperative issue in radiobiological study. Human mesenchymal stem cells (hMSCs) are multipotent and self-renewing, supporting the regeneration of damaged tissue, including tissue damaged by radiation. However, the responses of hMSCs to internal exposure to radionuclides are still insufficiently understood. In order to evaluate the adverse effects produced by internal exposure to tritiated water (HTO) at a low dose, hMSCs were exposed to 2 × 107 Bq/ml HTO, and the biological effects after the exposure were examined. Apoptosis and DNA double-strand breaks (DSBs) were assayed to analyze the cellular response to the damage induced by HTO. Slight enhancement of apoptosis was found after treatment, except at the dose of 9 mGy. The number of DSBs at 24 h post-irradiation showed that the DNA damage was able to be efficiently repaired by the hMSCs. Moreover, the increasing proportion of the cell population in S phase proved that the persistence of residual γH2AX foci at lower concentrations of HTO was attributable to the secondary production of DSBs in DNA replication. Our work adds to the available data, helping us understand the risk of stem cell transformation due to internal exposure and its correlation with low-dose radiation-induced carcinogenesis.
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Affiliation(s)
- Yi Quan
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, People’s Republic of China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, People’s Republic of China
| | - Jinxian Lin
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, People’s Republic of China
| | - Bing Deng
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, People’s Republic of China
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, People’s Republic of China
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55
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Velagapudi UK, Langelier MF, Delgado-Martin C, Diolaiti ME, Bakker S, Ashworth A, Patel BA, Shao X, Pascal JM, Talele TT. Design and Synthesis of Poly(ADP-ribose) Polymerase Inhibitors: Impact of Adenosine Pocket-Binding Motif Appendage to the 3-Oxo-2,3-dihydrobenzofuran-7-carboxamide on Potency and Selectivity. J Med Chem 2019; 62:5330-5357. [PMID: 31042381 PMCID: PMC7378964 DOI: 10.1021/acs.jmedchem.8b01709] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Poly(adenosine 5'-diphosphate-ribose) polymerase (PARP) inhibitors are a class of anticancer drugs that block the catalytic activity of PARP proteins. Optimization of our lead compound 1 (( Z)-2-benzylidene-3-oxo-2,3-dihydrobenzofuran-7-carboxamide; PARP-1 IC50 = 434 nM) led to a tetrazolyl analogue (51, IC50 = 35 nM) with improved inhibition. Isosteric replacement of the tetrazole ring with a carboxyl group (60, IC50 = 68 nM) gave a promising new lead, which was subsequently optimized to obtain analogues with potent PARP-1 IC50 values (4-197 nM). PARP enzyme profiling revealed that the majority of compounds are selective toward PARP-2 with IC50 values comparable to clinical inhibitors. X-ray crystal structures of the key inhibitors bound to PARP-1 illustrated the mode of interaction with analogue appendages extending toward the PARP-1 adenosine-binding pocket. Compound 81, an isoform-selective PARP-1/-2 (IC50 = 30 nM/2 nM) inhibitor, demonstrated selective cytotoxic effect toward breast cancer gene 1 ( BRCA1)-deficient cells compared to isogenic BRCA1-proficient cells.
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Affiliation(s)
- Uday Kiran Velagapudi
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John’s University, Queens, New York 11439, United States
| | - Marie-France Langelier
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal H3T 1J4 Canada
| | - Cristina Delgado-Martin
- UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California 94158, United States
| | - Morgan E. Diolaiti
- UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California 94158, United States
| | - Sietske Bakker
- UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California 94158, United States
| | - Alan Ashworth
- UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California 94158, United States
- Department of Medicine, University of California, San Francisco, California 94158, United States
| | - Bhargav A. Patel
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John’s University, Queens, New York 11439, United States
| | - Xuwei Shao
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John’s University, Queens, New York 11439, United States
| | - John M. Pascal
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal H3T 1J4 Canada
| | - Tanaji T. Talele
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John’s University, Queens, New York 11439, United States
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56
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Ulyanenko S, Pustovalova M, Koryakin S, Beketov E, Lychagin A, Ulyanenko L, Kaprin A, Grekhova A, M Ozerova A, V Ozerov I, Vorobyeva N, Shegay P, Ivanov S, Leonov S, Klokov D, Osipov AN. Formation of γH2AX and pATM Foci in Human Mesenchymal Stem Cells Exposed to Low Dose-Rate Gamma-Radiation. Int J Mol Sci 2019; 20:E2645. [PMID: 31146367 PMCID: PMC6600277 DOI: 10.3390/ijms20112645] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/21/2019] [Accepted: 05/23/2019] [Indexed: 12/12/2022] Open
Abstract
DNA double-strand breaks (DSB) are among the most harmful DNA lesions induced by ionizing radiation (IR). Although the induction and repair of radiation-induced DSB is well studied for acute irradiation, responses to DSB produced by chronic IR exposures are poorly understood, especially in human stem cells. The aim of this study was to examine the formation of DSB markers (γH2AX and phosphorylated kinase ATM, pATM, foci) in human mesenchymal stem cells (MSCs) exposed to chronic gamma-radiation (0.1 mGy/min) in comparison with acute irradiation (30 mGy/min) at cumulative doses of 30, 100, 160, 240 and 300 mGy. A linear dose-dependent increase in the number of both γH2AX and pATM foci, as well as co-localized γH2AX/pATM foci ("true" DSB), were observed after an acute radiation exposure. In contrast, the response of MSCs to a chronic low dose-rate IR exposure deviated from linearity towards a threshold model, for γH2AX, pATM foci and γH2AX/pATM foci, with an indication of a "plateau". The state of equilibrium between newly formed DSB at a low rate during the protracted exposure time and the elimination of a fraction of DSB is proposed as a mechanistic explanation of the non-linear DSB responses following a low dose-rate irradiation. This notion is supported by the observation of the elimination of a substantial fraction of DSB 6 h after the cessation of the exposures. Our results demonstrate non-linear dose responses for γH2AX and pATM foci in human MSCs exposed to low dose-rate IR and showed the existence of a threshold, which may have implications for radiation protection in humans.
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Affiliation(s)
- Stepan Ulyanenko
- A. Tsyb Medical Radiological Research Centre-Branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, Koroleva 4, Obninsk 249030, Russia.
| | - Margarita Pustovalova
- State Research Center-Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow 123098, Russia.
- Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow 119991, Russia.
- Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia.
| | - Sergey Koryakin
- A. Tsyb Medical Radiological Research Centre-Branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, Koroleva 4, Obninsk 249030, Russia.
| | - Evgenii Beketov
- A. Tsyb Medical Radiological Research Centre-Branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, Koroleva 4, Obninsk 249030, Russia.
| | - Anatolii Lychagin
- A. Tsyb Medical Radiological Research Centre-Branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, Koroleva 4, Obninsk 249030, Russia.
| | - Liliya Ulyanenko
- A. Tsyb Medical Radiological Research Centre-Branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, Koroleva 4, Obninsk 249030, Russia.
| | - Andrey Kaprin
- National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, Moscow 125284, Russia.
| | - Anna Grekhova
- State Research Center-Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow 123098, Russia.
- Emanuel Institute for Biochemical Physics, Russian Academy of Sciences, Moscow 119991, Russia.
| | - Alexandra M Ozerova
- Faculty of Biology, Lomonosov Moscow State University, GSP-1, Leninskie Gory, Moscow 119991, Russia.
| | - Ivan V Ozerov
- State Research Center-Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow 123098, Russia.
| | - Natalia Vorobyeva
- State Research Center-Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow 123098, Russia.
- Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow 119991, Russia.
| | - Peter Shegay
- Center for Innovative Radiological and Regenerative Technologies of the Ministry of Health of the Russian Federation, Koroleva 4, Obninsk 249030, Russia.
| | - Sergey Ivanov
- A. Tsyb Medical Radiological Research Centre-Branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, Koroleva 4, Obninsk 249030, Russia.
| | - Sergey Leonov
- Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia.
- Institute of Cell Biophysics, Russian Academy of Sciences, Institutskaya St., 3, Pushchino 142290, Russia.
| | - Dmitry Klokov
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
| | - Andreyan N Osipov
- State Research Center-Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow 123098, Russia.
- Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow 119991, Russia.
- Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia.
- Center for Innovative Radiological and Regenerative Technologies of the Ministry of Health of the Russian Federation, Koroleva 4, Obninsk 249030, Russia.
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57
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Alfano L, Caporaso A, Altieri A, Dell’Aquila M, Landi C, Bini L, Pentimalli F, Giordano A. Depletion of the RNA binding protein HNRNPD impairs homologous recombination by inhibiting DNA-end resection and inducing R-loop accumulation. Nucleic Acids Res 2019; 47:4068-4085. [PMID: 30799487 PMCID: PMC6486545 DOI: 10.1093/nar/gkz076] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 01/24/2019] [Accepted: 02/01/2019] [Indexed: 12/12/2022] Open
Abstract
DNA double strand break (DSB) repair through homologous recombination (HR) is crucial to maintain genome stability. DSB resection generates a single strand DNA intermediate, which is crucial for the HR process. We used a synthetic DNA structure, mimicking a resection intermediate, as a bait to identify proteins involved in this process. Among these, LC/MS analysis identified the RNA binding protein, HNRNPD. We found that HNRNPD binds chromatin, although this binding occurred independently of DNA damage. However, upon damage, HNRNPD re-localized to γH2Ax foci and its silencing impaired CHK1 S345 phosphorylation and the DNA end resection process. Indeed, HNRNPD silencing reduced: the ssDNA fraction upon camptothecin treatment; AsiSI-induced DSB resection; and RPA32 S4/8 phosphorylation. CRISPR/Cas9-mediated HNRNPD knockout impaired in vitro DNA resection and sensitized cells to camptothecin and olaparib treatment. We found that HNRNPD interacts with the heterogeneous nuclear ribonucleoprotein SAF-A previously associated with DNA damage repair. HNRNPD depletion resulted in an increased amount of RNA:DNA hybrids upon DNA damage. Both the expression of RNase H1 and RNA pol II inhibition recovered the ability to phosphorylate RPA32 S4/8 in HNRNPD knockout cells upon DNA damage, suggesting that RNA:DNA hybrid resolution likely rescues the defective DNA damage response of HNRNPD-depleted cells.
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Affiliation(s)
- Luigi Alfano
- Oncology Research Center of Mercogliano (CROM); Istituto Nazionale Tumori, IRCCS, Fondazione G. Pascale, Napoli, Italia
| | - Antonella Caporaso
- Department of Medical Biotechnologies, University of Siena, Siena, Italia
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA
| | - Angela Altieri
- Department of Medical Biotechnologies, University of Siena, Siena, Italia
| | - Milena Dell’Aquila
- Department of Medical Biotechnologies, University of Siena, Siena, Italia
| | - Claudia Landi
- Department of Life Sciences, University of Siena, Siena, Italia
| | - Luca Bini
- Department of Life Sciences, University of Siena, Siena, Italia
| | - Francesca Pentimalli
- Oncology Research Center of Mercogliano (CROM); Istituto Nazionale Tumori, IRCCS, Fondazione G. Pascale, Napoli, Italia
| | - Antonio Giordano
- Department of Medical Biotechnologies, University of Siena, Siena, Italia
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA
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58
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Wilson A, Menon V, Khan Z, Alam A, Litovchick L, Yakovlev V. Nitric oxide-donor/PARP-inhibitor combination: A new approach for sensitization to ionizing radiation. Redox Biol 2019; 24:101169. [PMID: 30889466 PMCID: PMC6423503 DOI: 10.1016/j.redox.2019.101169] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/08/2019] [Accepted: 03/11/2019] [Indexed: 02/06/2023] Open
Abstract
Recently, clinical development of PARP inhibitors (PARPi) expanded from using them as a single agent to combining them with DNA-damaging therapy to derive additional therapeutic benefit from stimulated DNA damage. Furthermore, inhibiting PARP in cancers with BRCA1/2 mutations has been shown to be an effective synthetic lethality approach either as a single agent or in combination with the different DNA damaging agents: chemotherapy or ionizing radiation (IR). However, inherited BRCA1/2 mutations account only for 5–10% of breast cancers, 10–15% of ovarian cancers, and lesser for the other cancers. Hence, for most of the cancer patients with BRCA1/2-proficient tumors, sensitization to DNA-damaging agents with PARPi is significantly less effective. We recently demonstrated that moderate, non-toxic concentrations of NO-donors inhibited BRCA1 expression, with subsequent inhibition of error-free HRR and increase of error-prone non-homologous end joining (NHEJ). We also demonstrated that the effect of NO-dependent block of BRCA1 expression can only be achieved in the presence of oxidative stress, a condition that characterizes the tumor microenvironment and is also a potential effect of IR. Hence, NO-donors in combination with PARPi, with effects limited by tumor microenvironment and irradiated area, suggest a precise tumor-targeted approach for radio-sensitization of BRCA1/2-proficient tumors. The combination with NO-donors allows PARPi to be successfully applied to a wider variety of tumors. The present work demonstrates a new drug combination (NO-donors and PARP-inhibitors) which demonstrated a high potency in sensitization of wide variety of tumors to ionizing radiation treatment.
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Affiliation(s)
- Aaron Wilson
- Department of Radiation Oncology, Massey Cancer Center, Virginia Commonwealth University, 401 College St., Richmond, VA 23298, United States
| | - Vijay Menon
- Department of Internal Medicine, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, United States
| | - Zubair Khan
- Department of Radiation Oncology, Massey Cancer Center, Virginia Commonwealth University, 401 College St., Richmond, VA 23298, United States
| | - Asim Alam
- Department of Radiation Oncology, Massey Cancer Center, Virginia Commonwealth University, 401 College St., Richmond, VA 23298, United States
| | - Larisa Litovchick
- Department of Internal Medicine, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, United States; Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, United States
| | - Vasily Yakovlev
- Department of Radiation Oncology, Massey Cancer Center, Virginia Commonwealth University, 401 College St., Richmond, VA 23298, United States.
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59
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Reilly NM, Yard BD, Pittman DL. Homologous Recombination-Mediated DNA Repair and Implications for Clinical Treatment of Repair Defective Cancers. Methods Mol Biol 2019; 1999:3-29. [PMID: 31127567 DOI: 10.1007/978-1-4939-9500-4_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Double-strand DNA breaks (DSBs) are generated by ionizing radiation and as intermediates during the processing of DNA, such as repair of interstrand cross-links and collapsed replication forks. These potentially deleterious DSBs are repaired primarily by the homologous recombination (HR) and nonhomologous end joining (NHEJ) DNA repair pathways. HR utilizes a homologous template to accurately restore damaged DNA, whereas NHEJ utilizes microhomology to join breaks in close proximity. The pathway available for DSB repair is dependent upon the cell cycle stage; for example, HR primarily functions during the S/G2 stages while NHEJ can repair DSBs at any cell cycle stage. Posttranslational modifications (PTMs) promote activity of specific pathways and subpathways through enzyme activation and precisely timed protein recruitment and degradation. This chapter provides an overview of PTMs occurring during DSB repair. In addition, clinical phenotypes associated with HR-defective cancers, such as mutational signatures used to predict response to poly(ADP-ribose) polymerase inhibitors, are discussed. Understanding these processes will provide insight into mechanisms of genome maintenance and likely identify targets and new avenues for therapeutic interventions.
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Affiliation(s)
- Nicole M Reilly
- Fondazione Piemontese per la Ricerca sul Cancro ONLUS, Candiolo, Italy
| | - Brian D Yard
- Department of Translational Hematology and Oncology Research, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Douglas L Pittman
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA.
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60
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Whelan DR, Lee WTC, Yin Y, Ofri DM, Bermudez-Hernandez K, Keegan S, Fenyo D, Rothenberg E. Spatiotemporal dynamics of homologous recombination repair at single collapsed replication forks. Nat Commun 2018; 9:3882. [PMID: 30250272 PMCID: PMC6155164 DOI: 10.1038/s41467-018-06435-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 09/06/2018] [Indexed: 01/07/2023] Open
Abstract
Homologous recombination (HR) is a crucial pathway for the repair of DNA double-strand breaks. BRCA1/2 breast cancer proteins are key players in HR via their mediation of RAD51 nucleofilament formation and function; however, their individual roles and crosstalk in vivo are unknown. Here we use super-resolution (SR) imaging to map the spatiotemporal kinetics of HR proteins, revealing the interdependent relationships that govern the dynamic interplay and progression of repair events. We show that initial single-stranded DNA/RAD51 nucleofilament formation is mediated by RAD52 or, in the absence of RAD52, by BRCA2. In contrast, only BRCA2 can orchestrate later RAD51 recombinase activity during homology search and resolution. Furthermore, we establish that upstream BRCA1 activity is critical for BRCA2 function. Our analyses reveal the underlying epistatic landscape of RAD51 functional dependence on RAD52, BRCA1, and BRCA2 during HR and explain the phenotypic similarity of diseases associated with mutations in these proteins.
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Affiliation(s)
- Donna R Whelan
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA.,Department of Pharmacy and Applied Science, La Trobe Institute for Molecular Science, La Trobe University, Bendigo, VIC, Australia
| | - Wei Ting C Lee
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - Yandong Yin
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - Dylan M Ofri
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - Keria Bermudez-Hernandez
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - Sarah Keegan
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - David Fenyo
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA.
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61
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Romanova LY, Mushinski F, Kovalchuk AL. Transcriptional activation of p21 Waf1 contributes to suppression of HR by p53 in response to replication arrest induced by camptothecin. Oncotarget 2018; 9:25427-25440. [PMID: 29875999 PMCID: PMC5986631 DOI: 10.18632/oncotarget.25172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/21/2018] [Indexed: 11/25/2022] Open
Abstract
The inhibitory effect of p53 on homologous recombination (HR) is exerted through sequestration of replication protein A (RPA). Release of the p53/RPA complex in response to replication stress is crucially dependent on the phosphorylation status of both proteins and is required for efficient DNA repair by HR. Phosphorylation of RPA within its RPA2 subunit by cyclin-dependent kinases (CDK) is an early event in the replication stress response. Here we investigated the role of transcriptional activation of the p53 downstream target, p21Waf1, on RPA2 phosphorylation, the stability of the p53/RPA complex and HR in cells undergoing replication arrest induced by camptothecin (CPT). We show that in CPT-treated cells, activation of p53 and p21Waf1 impedes RPA2 phosphorylation, while their depletion by siRNA stimulates it. The p53/RPA complex is more stable in wild-type cells than in cells depleted of p21Waf1. We used nocodazole-synchronized cells treated with CPT at the entrance to S phase to assess rates of HR. Regardless of their p53 or p21Waf1 status, the cells proceed through S phase at a similar rate and enter G2. While HR is low in wild-type cells and high in p53-depleted cells, only partial inhibition of HR is observed in the p21Waf1-depleted cells. This correlates with the extent of RPA sequestration by p53. Thus, in CPT-treated cells, p53-induced transcriptional activation of p21Waf1 regulates RPA2 phosphorylation, the stability of the p53/RPA complex and HR.
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Affiliation(s)
- Larisa Y Romanova
- The Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA.,The Virology and Cellular Immunology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, Maryland, USA
| | - Frederick Mushinski
- The Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Alexander L Kovalchuk
- The Virology and Cellular Immunology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, Maryland, USA
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62
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Sunavala-Dossabhoy G. Preserving salivary gland physiology against genotoxic damage - the Tousled way. Oral Dis 2018; 24:1390-1398. [PMID: 29383801 DOI: 10.1111/odi.12836] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 01/23/2018] [Accepted: 01/23/2018] [Indexed: 12/23/2022]
Abstract
Tousled and its homologs are evolutionarily conserved serine/threonine kinases present in plants and animals. Human Tousled-like kinases, TLK1 and TLK2, are implicated in chromatin assembly during DNA replication, chromosome segregation during mitosis, as well as in DNA damage response and repair. They share a high degree of sequence similarity, but have few non-redundant functions. Our laboratory has studied TLK1 and found that it increases the resistance of cells to ionizing radiation (IR) damage through expedited double-strand break (DSB) repair. DSBs are life-threatening lesions which when repaired restore DNA integrity and promote cell survival. A major focus in our laboratory is to dissect TLK1's role in DSB response and repair and study its usefulness in averting salivary gland hypofunction, a condition that invariably afflicts patients undergoing regional radiotherapy. The identification of anti-silencing factor 1 (ASF1), histone H3, and Rad9 as substrates of TLK1 links the protein to chromatin organization and DNA damage response and repair. However, recent findings of new interacting partners that include NEK1 suggest that TLK1 may play a broader role in DSB repair. This review provides a brief overview of the DNA damage response and DSB repair, and it highlights our current understanding of TLK1 in the process.
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Affiliation(s)
- G Sunavala-Dossabhoy
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
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63
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Hum YF, Jinks-Robertson S. DNA strand-exchange patterns associated with double-strand break-induced and spontaneous mitotic crossovers in Saccharomyces cerevisiae. PLoS Genet 2018; 14:e1007302. [PMID: 29579095 PMCID: PMC5886692 DOI: 10.1371/journal.pgen.1007302] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 04/05/2018] [Accepted: 03/08/2018] [Indexed: 11/24/2022] Open
Abstract
Mitotic recombination can result in loss of heterozygosity and chromosomal rearrangements that shape genome structure and initiate human disease. Engineered double-strand breaks (DSBs) are a potent initiator of recombination, but whether spontaneous events initiate with the breakage of one or both DNA strands remains unclear. In the current study, a crossover (CO)-specific assay was used to compare heteroduplex DNA (hetDNA) profiles, which reflect strand exchange intermediates, associated with DSB-induced versus spontaneous events in yeast. Most DSB-induced CO products had the two-sided hetDNA predicted by the canonical DSB repair model, with a switch in hetDNA position from one product to the other at the position of the break. Approximately 40% of COs, however, had hetDNA on only one side of the initiating break. This anomaly can be explained by a modified model in which there is frequent processing of an early invasion (D-loop) intermediate prior to extension of the invading end. Finally, hetDNA tracts exhibited complexities consistent with frequent expansion of the DSB into a gap, migration of strand-exchange junctions, and template switching during gap-filling reactions. hetDNA patterns in spontaneous COs isolated in either a wild-type background or in a background with elevated levels of reactive oxygen species (tsa1Δ mutant) were similar to those associated with the DSB-induced events, suggesting that DSBs are the major instigator of spontaneous mitotic recombination in yeast.
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Affiliation(s)
- Yee Fang Hum
- Department of Molecular Genetics and Microbiology and the University Program in Genetics and Genomics, Duke University, Durham, North Carolina, United States of America
| | - Sue Jinks-Robertson
- Department of Molecular Genetics and Microbiology and the University Program in Genetics and Genomics, Duke University, Durham, North Carolina, United States of America
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Bloom MS, Koshland D, Guacci V. Cohesin Function in Cohesion, Condensation, and DNA Repair Is Regulated by Wpl1p via a Common Mechanism in Saccharomyces cerevisiae. Genetics 2018; 208:111-124. [PMID: 29158426 PMCID: PMC5753852 DOI: 10.1534/genetics.117.300537] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 11/16/2017] [Indexed: 11/18/2022] Open
Abstract
Cohesin tethers DNA to mediate sister chromatid cohesion, chromosome condensation, and DNA repair. How the cell regulates cohesin to perform these distinct functions remains to be elucidated. One cohesin regulator, Wpl1p, was characterized in Saccharomyces cerevisiae as a promoter of efficient cohesion and an inhibitor of condensation. Wpl1p is also required for resistance to DNA-damaging agents. Here, we provide evidence that Wpl1p promotes the timely repair of DNA damage induced during S-phase. Previous studies have indicated that Wpl1p destabilizes cohesin's binding to DNA by modulating the interface between the cohesin subunits Mcd1p and Smc3p Our results suggest that Wpl1p likely modulates this interface to regulate all of cohesin's biological functions. Furthermore, we show that Wpl1p regulates cohesion and condensation through the formation of a functional complex with another cohesin-associated factor, Pds5p In contrast, Wpl1p regulates DNA repair independently of its interaction with Pds5p Together, these results suggest that Wpl1p regulates distinct biological functions of cohesin by Pds5p-dependent and -independent modulation of the Smc3p/Mcd1p interface.
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Affiliation(s)
- Michelle S Bloom
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720
| | - Douglas Koshland
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720
| | - Vincent Guacci
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720
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O’Kane GM, Connor AA, Gallinger S. Characterization, Detection, and Treatment Approaches for Homologous Recombination Deficiency in Cancer. Trends Mol Med 2017; 23:1121-1137. [DOI: 10.1016/j.molmed.2017.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 10/22/2017] [Accepted: 10/23/2017] [Indexed: 02/07/2023]
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66
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Gravells P, Neale J, Grant E, Nathubhai A, Smith KM, James DI, Bryant HE. Radiosensitization with an inhibitor of poly(ADP-ribose) glycohydrolase: A comparison with the PARP1/2/3 inhibitor olaparib. DNA Repair (Amst) 2017; 61:25-36. [PMID: 29179156 PMCID: PMC5765821 DOI: 10.1016/j.dnarep.2017.11.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 11/17/2017] [Accepted: 11/17/2017] [Indexed: 12/12/2022]
Abstract
PARG and PARP inhibition both radiosensitize. PARP and PARG inhibition both alter the DNA damage response following irradiation (IR). PARP and PARG inhibition both alter homologous recombination following IR. Only PARG inhibition induces rapid activation of non-homologous end-joining post-IR. Only inhibition of PARG causes accumulation of cells in metaphase post-IR.
Upon DNA binding the poly(ADP-ribose) polymerase family of enzymes (PARPs) add multiple ADP-ribose subunits to themselves and other acceptor proteins. Inhibitors of PARPs have become an exciting and real prospect for monotherapy and as sensitizers to ionising radiation (IR). The action of PARPs are reversed by poly(ADP-ribose) glycohydrolase (PARG). Until recently studies of PARG have been limited by the lack of an inhibitor. Here, a first in class, specific, and cell permeable PARG inhibitor, PDD00017273, is shown to radiosensitize. Further, PDD00017273 is compared with the PARP1/2/3 inhibitor olaparib. Both olaparib and PDD00017273 altered the repair of IR-induced DNA damage, resulting in delayed resolution of RAD51 foci compared with control cells. However, only PARG inhibition induced a rapid increase in IR-induced activation of PRKDC (DNA-PK) and perturbed mitotic progression. This suggests that PARG has additional functions in the cell compared with inhibition of PARP1/2/3, likely via reversal of tankyrase activity and/or that inhibiting the removal of poly(ADP-ribose) (PAR) has a different consequence to inhibiting PAR addition. Overall, our data are consistent with previous genetic findings, reveal new insights into the function of PAR metabolism following IR and demonstrate for the first time the therapeutic potential of PARG inhibitors as radiosensitizing agents.
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Affiliation(s)
- Polly Gravells
- Academic Unit of Molecular Oncology, Sheffield Institute for Nucleic Acids (SInFoNiA), Department of Oncology and Metabolism, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - James Neale
- Academic Unit of Molecular Oncology, Sheffield Institute for Nucleic Acids (SInFoNiA), Department of Oncology and Metabolism, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - Emma Grant
- Academic Unit of Molecular Oncology, Sheffield Institute for Nucleic Acids (SInFoNiA), Department of Oncology and Metabolism, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - Amit Nathubhai
- Drug and Target Discovery, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, Somerset, BA2 7AY, United Kingdom
| | - Kate M Smith
- Drug Discovery Unit, Cancer Research UK Manchester Institute, The University of Manchester, Wilmslow Road, Manchester, M20 4BX, United Kingdom
| | - Dominic I James
- Drug Discovery Unit, Cancer Research UK Manchester Institute, The University of Manchester, Wilmslow Road, Manchester, M20 4BX, United Kingdom
| | - Helen E Bryant
- Academic Unit of Molecular Oncology, Sheffield Institute for Nucleic Acids (SInFoNiA), Department of Oncology and Metabolism, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom.
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PARI Regulates Stalled Replication Fork Processing To Maintain Genome Stability upon Replication Stress in Mice. Mol Cell Biol 2017; 37:MCB.00117-17. [PMID: 28894029 DOI: 10.1128/mcb.00117-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 09/07/2017] [Indexed: 12/14/2022] Open
Abstract
DNA replication is frequently perturbed by intrinsic, as well as extrinsic, genotoxic stress. At damaged forks, DNA replication and repair activities require proper coordination to maintain genome integrity. We show here that PARI antirecombinase plays an essential role in modulating the initial response to replication stress in mice. PARI is functionally dormant at replisomes during normal replication, but upon replication stress, it enhances nascent-strand shortening that is regulated by RAD51 and MRE11. PARI then promotes double-strand break induction, followed by new origin firing instead of replication restart. Such PARI function is apparently obstructive to replication but is nonetheless physiologically required for chromosome stability in vivo and ex vivo Of note, Pari-deficient embryonic stem cells exhibit spontaneous chromosome instability, which is attenuated by differentiation induction, suggesting that pluripotent stem cells have a preferential requirement for PARI that acts against endogenous replication stress. PARI is a latent modulator of stalled fork processing, which is required for stable genome inheritance under both endogenous and exogenous replication stress in mice.
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68
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Reh WA, Nairn RS, Lowery MP, Vasquez KM. The homologous recombination protein RAD51D protects the genome from large deletions. Nucleic Acids Res 2017; 45:1835-1847. [PMID: 27924006 PMCID: PMC5389663 DOI: 10.1093/nar/gkw1204] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 11/28/2016] [Indexed: 12/20/2022] Open
Abstract
Homologous recombination (HR) is a DNA double-strand break (DSB) repair pathway that protects the genome from chromosomal instability. RAD51 mediator proteins (i.e. paralogs) are critical for efficient HR in mammalian cells. However, how HR-deficient cells process DSBs is not clear. Here, we utilized a loss-of-function HR-reporter substrate to simultaneously monitor HR-mediated gene conversion and non-conservative mutation events. The assay is designed around a heteroallelic duplication of the Aprt gene at its endogenous locus in isogenic Chinese hamster ovary cell lines. We found that RAD51D-deficient cells had a reduced capacity for HR-mediated gene conversion both spontaneously and in response to I-SceI-induced DSBs. Further, RAD51D-deficiency shifted DSB repair toward highly deleterious single-strand annealing (SSA) and end-joining processes that led to the loss of large chromosomal segments surrounding site-specific DSBs at an exceptionally high frequency. Deletions in the proximity of the break were due to a non-homologous end-joining pathway, while larger deletions were processed via a SSA pathway. Overall, our data revealed that, in addition to leading to chromosomal abnormalities, RAD51D-deficiency resulted in a high frequency of deletions advancing our understanding of how a RAD51 paralog is involved in maintaining genomic stability and how its deficiency may predispose cells to tumorigenesis.
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Affiliation(s)
- Wade A Reh
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, Austin, TX 78723, USA
| | - Rodney S Nairn
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center Science Park, Smithville, TX 78957, USA
| | - Megan P Lowery
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center Science Park, Smithville, TX 78957, USA
| | - Karen M Vasquez
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Dell Pediatric Research Institute, Austin, TX 78723, USA
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Wiest NE, Houghtaling S, Sanchez JC, Tomkinson AE, Osley MA. The SWI/SNF ATP-dependent nucleosome remodeler promotes resection initiation at a DNA double-strand break in yeast. Nucleic Acids Res 2017; 45:5887-5900. [PMID: 28398510 PMCID: PMC5449591 DOI: 10.1093/nar/gkx221] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/06/2017] [Indexed: 12/27/2022] Open
Abstract
DNA double-strand breaks (DSBs) are repaired by either the non-homologous end joining (NHEJ) or homologous recombination (HR) pathway. Pathway choice is determined by the generation of 3΄ single-strand DNA overhangs at the break that are initiated by the action of the Mre11-Rad50-Xrs2 (MRX) complex to direct repair toward HR. DSB repair occurs in the context of chromatin, and multiple chromatin regulators have been shown to play important roles in the repair process. We have investigated the role of the SWI/SNF ATP-dependent nucleosome-remodeling complex in the repair of a defined DNA DSB. SWI/SNF was previously shown to regulate presynaptic events in HR, but its function in these events is unknown. We find that in the absence of functional SWI/SNF, the initiation of DNA end resection is significantly delayed. The delay in resection initiation is accompanied by impaired recruitment of MRX to the DSB, and other functions of MRX in HR including the recruitment of long-range resection factors and activation of the DNA damage response are also diminished. These phenotypes are correlated with a delay in the eviction of nucleosomes surrounding the DSB. We propose that SWI/SNF orchestrates the recruitment of a pool of MRX that is specifically dedicated to HR.
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Affiliation(s)
- Nathaniel E Wiest
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA.,Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Scott Houghtaling
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Joseph C Sanchez
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Alan E Tomkinson
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA.,Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Mary Ann Osley
- Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
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Koosha F, Neshasteh-Riz A, Takavar A, Eyvazzadeh N, Mazaheri Z, Eynali S, Mousavi M. The combination of A-966492 and Topotecan for effective radiosensitization on glioblastoma spheroids. Biochem Biophys Res Commun 2017; 491:1092-1097. [PMID: 28797568 DOI: 10.1016/j.bbrc.2017.08.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 08/04/2017] [Indexed: 11/18/2022]
Abstract
Radiotherapy is one of the modalities in the treatment of glioblastoma patients, but glioma tumors are resistant to radiation and also chemotherapy drugs. Thus, researchers are investigating drugs which have radiosensitization capabilities in order to improve radiotherapy. PARP enzymes and topoisomerase I enzymes have a critical role in repairing DNA damage in tumor cells. Thus, inhibiting activity of these enzymes helps stop DNA damage repair and increase DSB lethal damages. In the current study, we investigated the combination of TPT as a topoisomerase I inhibitor, and A-966492 as a novel PARP inhibitor for further radiosensitization. U87MG cells (a human glioblastoma cell line) were cultured in Poly-Hema coated flasks to reach 300 μm-diameter spheroids. Treatments were accomplished by using non-toxic concentrations of A-966492 and Topotecan. The surviving fraction of treated cells was determined by clonogenic assay after treatment with drugs and 6 MV X-ray. The γ-H2AX expression was measured by an immunofluorescence staining method to examine the influence of A-966492, TPT and radiation on the induction of double stranded DNA breaks. Treatments using the A-966492 drug were conducted in concentration of 1 μM. Combining A-966492 and TPT with radiation yielded enhanced cell killing, as demonstrated by a sensitizer enhancement ratio at 50% survival (SER50) 1.39 and 1.16 respectively. Radio- and chemo-sensitization was further enhanced when A-966492 was combined with both X-ray and TPT, with SER50 of 1.53. Also γ-H2AX expression was higher in the group treated with a combination of drugs and radiation. A-966492 is an effective PARP inhibitor and has significant radio-sensitivity on U87MG spheroids. By accumulating cells in the S phase and by inhibiting the DNA damage repair, TPT enhanced radio-sensitivity. A-966492 combined with TPT as a topoisomerase I inhibitor had additive radio-sensitizing effects. As a result, applying PARP and topoisomerase I inhibitors can be a suitable strategy for improving radiotherapy in clinics.
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Affiliation(s)
- Fereshteh Koosha
- Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Neshasteh-Riz
- Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Radiation Sciences, School of Para Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Abbas Takavar
- Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| | - Nazila Eyvazzadeh
- Radiation Research Center, Faculty of Para Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Zohreh Mazaheri
- Department of Anatomical Sciences, Medical Sciences Faculty, Tarbiat Modares University, Tehran, Iran
| | - Samira Eynali
- Radiation Biology Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mehdi Mousavi
- School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran
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71
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Parrotta R, Okonska A, Ronner M, Weder W, Stahel R, Penengo L, Felley-Bosco E. A Novel BRCA1-Associated Protein-1 Isoform Affects Response of Mesothelioma Cells to Drugs Impairing BRCA1-Mediated DNA Repair. J Thorac Oncol 2017; 12:1309-1319. [DOI: 10.1016/j.jtho.2017.03.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 03/08/2017] [Accepted: 03/21/2017] [Indexed: 01/05/2023]
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72
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van den Tempel N, Odijk H, van Holthe N, Naipal K, Raams A, Eppink B, van Gent DC, Hardillo J, Verduijn GM, Drooger JC, van Rhoon GC, Smedts DHPM, van Doorn HC, Boormans JL, Jager A, Franckena M, Kanaar R. Heat-induced BRCA2 degradation in human tumours provides rationale for hyperthermia-PARP-inhibitor combination therapies. Int J Hyperthermia 2017; 34:407-414. [PMID: 28705099 DOI: 10.1080/02656736.2017.1355487] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Hyperthermia (40-44 °C) effectively sensitises tumours to radiotherapy by locally altering tumour biology. One of the effects of heat at the cellular level is inhibition of DNA repair by homologous recombination via degradation of the BRCA2-protein. This suggests that hyperthermia can expand the group of patients that benefit from PARP-inhibitors, a drug exploiting homologous recombination deficiency. Here, we explore whether the molecular mechanisms that cause heat-mediated degradation of BRCA2 are conserved in cell lines from various origins and, most importantly, whether, BRCA2 protein levels can be attenuated by heat in freshly biopted human tumours. EXPERIMENTAL DESIGN Cells from four established cell lines and from freshly biopsied material of cervical (15), head- and neck (9) or bladder tumours (27) were heated to 42 °C for 60 min ex vivo. In vivo hyperthermia was studied by taking two biopsies of the same breast or cervical tumour: one before and one after treatment. BRCA2 protein levels were measured by immunoblotting. RESULTS We found decreased BRCA2-levels after hyperthermia in all established cell lines and in 91% of all tumours treated ex vivo. For tumours treated with hyperthermia in vivo, technical issues and intra-tumour heterogeneity prevented obtaining interpretable results. CONCLUSIONS This study demonstrates that heat-mediated degradation of BRCA2 occurs in tumour material directly derived from patients. Although BRCA2-degradation may not be a practical biomarker for heat deposition in situ, it does suggest that application of hyperthermia could be an effective method to expand the patient group that could benefit from PARP-inhibitors.
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Affiliation(s)
- Nathalie van den Tempel
- a Department of Molecular Genetics , Cancer Genomics Centre Netherlands Erasmus University Medical Centre , Rotterdam , The Netherlands
| | - Hanny Odijk
- a Department of Molecular Genetics , Cancer Genomics Centre Netherlands Erasmus University Medical Centre , Rotterdam , The Netherlands
| | - Netteke van Holthe
- b Department of Radiation Oncology , Erasmus MC Cancer Institute , Rotterdam , The Netherlands
| | - Kishan Naipal
- a Department of Molecular Genetics , Cancer Genomics Centre Netherlands Erasmus University Medical Centre , Rotterdam , The Netherlands
| | - Anja Raams
- a Department of Molecular Genetics , Cancer Genomics Centre Netherlands Erasmus University Medical Centre , Rotterdam , The Netherlands
| | - Berina Eppink
- a Department of Molecular Genetics , Cancer Genomics Centre Netherlands Erasmus University Medical Centre , Rotterdam , The Netherlands
| | - Dik C van Gent
- a Department of Molecular Genetics , Cancer Genomics Centre Netherlands Erasmus University Medical Centre , Rotterdam , The Netherlands
| | - Jose Hardillo
- c Department of Otolaryngology and Head and Neck Surgery , Erasmus University Medical Centre , Rotterdam , The Netherlands
| | - Gerda M Verduijn
- b Department of Radiation Oncology , Erasmus MC Cancer Institute , Rotterdam , The Netherlands
| | - Jan C Drooger
- d Department of Medical Oncology , Ikazia Hospital , Rotterdam , The Netherlands
| | - Gerard C van Rhoon
- b Department of Radiation Oncology , Erasmus MC Cancer Institute , Rotterdam , The Netherlands
| | - Dineke H P M Smedts
- e Department of Gynaecological Oncology , Erasmus University Medical Centre , Rotterdam , The Netherlands
| | - Helena C van Doorn
- e Department of Gynaecological Oncology , Erasmus University Medical Centre , Rotterdam , The Netherlands
| | - Joost L Boormans
- f Department of Urology , Erasmus MC Cancer Institute , Rotterdam , The Netherlands
| | - Agnes Jager
- g Department of Medical Oncology , Erasmus MC Cancer Institute , Rotterdam , The Netherlands
| | - Martine Franckena
- b Department of Radiation Oncology , Erasmus MC Cancer Institute , Rotterdam , The Netherlands
| | - Roland Kanaar
- a Department of Molecular Genetics , Cancer Genomics Centre Netherlands Erasmus University Medical Centre , Rotterdam , The Netherlands
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Caruso D, Papa A, Tomao S, Vici P, Panici PB, Tomao F. Niraparib in ovarian cancer: results to date and clinical potential. Ther Adv Med Oncol 2017; 9:579-588. [PMID: 29081841 PMCID: PMC5564880 DOI: 10.1177/1758834017718775] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 06/09/2017] [Indexed: 12/26/2022] Open
Abstract
Ovarian cancer is the first cause of death from gynaecological malignancy. Germline mutation in BRCA1 and 2, two genes involved in the mechanisms of reparation of DNA damage, are showed to be related with the incidence of breast and ovarian cancer, both sporadic and familiar. PARP is a family of enzymes involved in the base excision repair (BER) system. The introduction of inhibitors of PARP in patients with BRCA-mutated ovarian cancer is correlated with the concept of synthetic lethality. Among the PARP inhibitors introduced in clinical practice, niraparib showed interesting results in a phase III trial in the setting of maintenance treatment in ovarian cancer, after platinum-based chemotherapy. Interestingly, was niraparib showed to be efficacious not only in BRCA-mutated patients, but also in patients with other alterations of the homologous recombination (HR) system and in patients with unknown alterations. These results position niraparib as the first PARP-inhibitor with clinically and statistically significant results also in patients with no alterations in BRCA 1/2 and other genes involved in the DNA repair system. Even if the results are potentially practice-changing, the action of niraparib must be further studied and deepened.
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Affiliation(s)
- Davide Caruso
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome 'Sapienza', Latina, Italy
| | - Anselmo Papa
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome 'Sapienza', Corso della Repubblica 79, 04100, Latina, Italy
| | - Silverio Tomao
- Department of Medico-Surgical Sciences and Biotechnologies, University of Rome 'Sapienza', Latina, Italy
| | - Patrizia Vici
- Division of Medical Oncology 2, 'Regina Elena' National Cancer Institute, Rome, Italy
| | | | - Federica Tomao
- Department of Gynaecology and Obstetrics, University of Rome 'Sapienza', Rome, Italy; Department of Gynecology, University of Heraklion, Heraklion, Greece
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Orta ML, Pastor N, Burgos-Morón E, Domínguez I, Calderón-Montaño JM, Huertas Castaño C, López-Lázaro M, Helleday T, Mateos S. Zebularine induces replication-dependent double-strand breaks which are preferentially repaired by homologous recombination. DNA Repair (Amst) 2017; 57:116-124. [PMID: 28732309 DOI: 10.1016/j.dnarep.2017.07.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 06/30/2017] [Accepted: 07/06/2017] [Indexed: 12/19/2022]
Abstract
Zebularine is a second-generation, highly stable hydrophilic inhibitor of DNA methylation with oral bioavailability that preferentially target cancer cells. It acts primarily as a trap for DNA methyl transferases (DNMTs) protein by forming covalent complexes between DNMT protein and zebularine-substrate DNA. It's well documented that replication-blocking DNA lesions can cause replication fork collapse and thereby to the formation of DNA double-strand breaks (DSB). DSB are dangerous lesions that can lead to potentially oncogenic genomic rearrangements or cell death. The two major pathways for repair of DSB are non-homologous end joining (NHEJ) and homologous recombination (HR). Recently, multiple functions for the HR machinery have been identified at arrested forks. Here we investigate in more detail the importance of the lesions induced by zebularine in terms of DNA damage and cytotoxicity as well as the role of HR in the repair of these lesions. When we examined the contribution of NHEJ and HR in the repair of DSB induced by zebularine we found that these breaks were preferentially repaired by HR. Also we show that the production of DSB is dependent on active replication. To test this, we determined chromosome damage by zebularine while transiently inhibiting DNA synthesis. Here we report that cells deficient in single-strand break (SSB) repair are hypersensitive to zebularine. We have observed more DSB induced by zebularine in XRCC1 deficient cells, likely to be the result of conversion of SSB into toxic DSB when encountered by a replication fork. Furthermore we demonstrate that HR is required for the repair of these breaks. Overall, our data suggest that zebularine induces replication-dependent DSB which are preferentially repaired by HR.
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Affiliation(s)
- Manuel Luis Orta
- Department of Cell Biology, University of Seville, Avda. Reina Mercedes 6, 41012 Seville, Spain,.
| | - Nuria Pastor
- Department of Cell Biology, University of Seville, Avda. Reina Mercedes 6, 41012 Seville, Spain
| | - Estefanía Burgos-Morón
- Department of Pharmacology, Faculty of Pharmacy, University of Seville, c/Professor García González, No. 2, 41012, Seville, Spain
| | - Inmaculada Domínguez
- Department of Cell Biology, University of Seville, Avda. Reina Mercedes 6, 41012 Seville, Spain
| | - José Manuel Calderón-Montaño
- Department of Pharmacology, Faculty of Pharmacy, University of Seville, c/Professor García González, No. 2, 41012, Seville, Spain
| | - Carlos Huertas Castaño
- Department of Cell Biology, University of Seville, Avda. Reina Mercedes 6, 41012 Seville, Spain
| | - Miguel López-Lázaro
- Department of Pharmacology, Faculty of Pharmacy, University of Seville, c/Professor García González, No. 2, 41012, Seville, Spain
| | - Thomas Helleday
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, S-17121, Stockholm, Sweden
| | - Santiago Mateos
- Department of Cell Biology, University of Seville, Avda. Reina Mercedes 6, 41012 Seville, Spain,.
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75
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Petibone DM, Mustafa T, Bourdo SE, Lafont A, Ding W, Karmakar A, Nima ZA, Watanabe F, Casciano D, Morris SM, Dobrovolsky VN, Biris AS. p53
-competent cells and p53
-deficient cells display different susceptibility to oxygen functionalized graphene cytotoxicity and genotoxicity. J Appl Toxicol 2017; 37:1333-1345. [DOI: 10.1002/jat.3472] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Dayton M. Petibone
- Division of Genetic and Molecular Toxicology; National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Thikra Mustafa
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
- Department of Medical Bioscience; College of Veterinary Medicine, University of Kirkuk; Kirkuk Iraq
| | - Shawn E. Bourdo
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
| | - Andersen Lafont
- Nanotechnology Core Facility, Office of Scientific Coordination, National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Wei Ding
- Division of Genetic and Molecular Toxicology; National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Alokita Karmakar
- Nanotechnology Core Facility, Office of Scientific Coordination, National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Zeid A. Nima
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
| | - Fumiya Watanabe
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
| | - Daniel Casciano
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
| | - Suzanne M. Morris
- Division of Genetic and Molecular Toxicology; National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Vasily N. Dobrovolsky
- Division of Genetic and Molecular Toxicology; National Center for Toxicological Research, FDA; Jefferson AR 72079 USA
| | - Alexandru S. Biris
- Center for Integrative Nanotechnology Sciences; University of Arkansas at Little Rock; Little Rock AR 72204 USA
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76
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Gadducci A, Guerrieri ME. PARP inhibitors alone and in combination with other biological agents in homologous recombination deficient epithelial ovarian cancer: From the basic research to the clinic. Crit Rev Oncol Hematol 2017; 114:153-165. [PMID: 28477743 DOI: 10.1016/j.critrevonc.2017.04.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/15/2017] [Accepted: 04/11/2017] [Indexed: 12/21/2022] Open
Abstract
Hereditary epithelial ovarian cancer [EOC] in germline BRCA mutation (gBRCAm) carriers has a distinct clinical behavior characterized by younger age, high- grade serous histology, advanced stage, visceral distribution of disease, high response to platinum and other non-platinum agents and better clinical outcome. Sporadic EOC with homologous recombination deficiency [HDR] but no gBRCAm has the same biological and clinical behavior as EOC in gBRCAm carriers ("BRCAness"phenotype). Biomarkers are in development to enable an accurate definition of molecular features of BRCAness phenotype, and trials are warranted to determine whether such HDR signature will predict sensitivity to PARP inhibitors in sporadic EOC. Moreover, the link between PARP inhibition and angiogenesis suppression, the immunologic properties of EOC in gBRCAm carriers, the HRD induced by PI3K inhibition in EOC cells in vitro strongly support novel clinical trials testing the combination of PARP inhibitors with other biological agents.
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Affiliation(s)
- Angiolo Gadducci
- Department of Clinical and Experimental Medicine, Division of Gynecology and Obstetrics, University of Pisa, Italy.
| | - Maria Elena Guerrieri
- Department of Clinical and Experimental Medicine, Division of Gynecology and Obstetrics, University of Pisa, Italy
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77
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Gravells P, Grant E, Smith KM, James DI, Bryant HE. Specific killing of DNA damage-response deficient cells with inhibitors of poly(ADP-ribose) glycohydrolase. DNA Repair (Amst) 2017; 52:81-91. [PMID: 28254358 PMCID: PMC5360195 DOI: 10.1016/j.dnarep.2017.02.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/16/2017] [Accepted: 02/13/2017] [Indexed: 12/12/2022]
Abstract
Poly(ADP-ribosylation) of proteins following DNA damage is well studied and the use of poly(ADP-ribose) polymerase (PARP) inhibitors as therapeutic agents is an exciting prospect for the treatment of many cancers. Poly(ADP-ribose) glycohydrolase (PARG) has endo- and exoglycosidase activities which can cleave glycosidic bonds, rapidly reversing the action of PARP enzymes. Like addition of poly(ADP-ribose) (PAR) by PARP, removal of PAR by PARG is also thought to be required for repair of DNA strand breaks and for continued replication at perturbed forks. Here we use siRNA to show a synthetic lethal relationship between PARG and BRCA1, BRCA2, PALB2, FAM175A (ABRAXAS) and BARD1. In addition, we demonstrate that MCF7 cells depleted of these proteins are sensitive to Gallotannin and a novel and specific PARG inhibitor PDD00017273. We confirm that PARG inhibition increases endogenous DNA damage, stalls replication forks and increases homologous recombination, and propose that it is the lack of homologous recombination (HR) proteins at PARG inhibitor-induced stalled replication forks that induces cell death. Interestingly not all genes that are synthetically lethal with PARP result in sensitivity to PARG inhibitors, suggesting that although there is overlap, the functions of PARP and PARG may not be completely identical. These data together add further evidence to the possibility that single treatment therapy with PARG inhibitors could be used for treatment of certain HR deficient tumours and provide insight into the relationship between PARP, PARG and the processes of DNA repair.
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Affiliation(s)
- Polly Gravells
- Academic Unit of Molecular Oncology, Sheffield Institute for Nucleic Acids (SInFoNiA), Department of Oncology and Metabolism, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - Emma Grant
- Academic Unit of Molecular Oncology, Sheffield Institute for Nucleic Acids (SInFoNiA), Department of Oncology and Metabolism, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom
| | - Kate M Smith
- Drug Discovery Unit, Cancer Research UK Manchester Institute, The University of Manchester, Wilmslow Road, Manchester, M20 4BX, United Kingdom
| | - Dominic I James
- Drug Discovery Unit, Cancer Research UK Manchester Institute, The University of Manchester, Wilmslow Road, Manchester, M20 4BX, United Kingdom
| | - Helen E Bryant
- Academic Unit of Molecular Oncology, Sheffield Institute for Nucleic Acids (SInFoNiA), Department of Oncology and Metabolism, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, United Kingdom.
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78
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Bothmer A, Phadke T, Barrera LA, Margulies CM, Lee CS, Buquicchio F, Moss S, Abdulkerim HS, Selleck W, Jayaram H, Myer VE, Cotta-Ramusino C. Characterization of the interplay between DNA repair and CRISPR/Cas9-induced DNA lesions at an endogenous locus. Nat Commun 2017; 8:13905. [PMID: 28067217 PMCID: PMC5227551 DOI: 10.1038/ncomms13905] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 11/11/2016] [Indexed: 12/25/2022] Open
Abstract
The CRISPR-Cas9 system provides a versatile toolkit for genome engineering that can introduce various DNA lesions at specific genomic locations. However, a better understanding of the nature of these lesions and the repair pathways engaged is critical to realizing the full potential of this technology. Here we characterize the different lesions arising from each Cas9 variant and the resulting repair pathway engagement. We demonstrate that the presence and polarity of the overhang structure is a critical determinant of double-strand break repair pathway choice. Similarly, single nicks deriving from different Cas9 variants differentially activate repair: D10A but not N863A-induced nicks are repaired by homologous recombination. Finally, we demonstrate that homologous recombination is required for repairing lesions using double-stranded, but not single-stranded DNA as a template. This detailed characterization of repair pathway choice in response to CRISPR-Cas9 enables a more deterministic approach for designing research and therapeutic genome engineering strategies.
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Affiliation(s)
- Anne Bothmer
- Editas Medicine, 11 Hurley Street, Cambridge, Massachusetts 02141, USA
| | - Tanushree Phadke
- Editas Medicine, 11 Hurley Street, Cambridge, Massachusetts 02141, USA
| | - Luis A. Barrera
- Editas Medicine, 11 Hurley Street, Cambridge, Massachusetts 02141, USA
| | | | - Christina S. Lee
- Editas Medicine, 11 Hurley Street, Cambridge, Massachusetts 02141, USA
| | - Frank Buquicchio
- Editas Medicine, 11 Hurley Street, Cambridge, Massachusetts 02141, USA
| | - Sean Moss
- Editas Medicine, 11 Hurley Street, Cambridge, Massachusetts 02141, USA
| | | | - William Selleck
- Editas Medicine, 11 Hurley Street, Cambridge, Massachusetts 02141, USA
| | - Hariharan Jayaram
- Editas Medicine, 11 Hurley Street, Cambridge, Massachusetts 02141, USA
| | - Vic E. Myer
- Editas Medicine, 11 Hurley Street, Cambridge, Massachusetts 02141, USA
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79
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Vriend LEM, Krawczyk PM. Nick-initiated homologous recombination: Protecting the genome, one strand at a time. DNA Repair (Amst) 2016; 50:1-13. [PMID: 28087249 DOI: 10.1016/j.dnarep.2016.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 12/17/2016] [Indexed: 01/13/2023]
Abstract
Homologous recombination (HR) is an essential, widely conserved mechanism that utilizes a template for accurate repair of DNA breaks. Some early HR models, developed over five decades ago, anticipated single-strand breaks (nicks) as initiating lesions. Subsequent studies favored a more double-strand break (DSB)-centered view of HR initiation and at present this pathway is primarily considered to be associated with DSB repair. However, mounting evidence suggests that nicks can indeed initiate HR directly, without first being converted to DSBs. Moreover, recent studies reported on novel branches of nick-initiated HR (nickHR) that rely on single-, rather than double-stranded repair templates and that are characterized by mechanistically and genetically unique properties. The physiological significance of nickHR is not well documented, but its high-fidelity nature and low mutagenic potential are relevant in recently developed, precise gene editing approaches. Here, we review the evidence for stimulation of HR by nicks, as well as the data on the interactions of nickHR with other DNA repair pathways and on its mechanistic properties. We conclude that nickHR is a bona-fide pathway for nick repair, sharing the molecular machinery with the canonical HR but nevertheless characterized by unique properties that secure its inclusion in DNA repair models and warrant future investigations.
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Affiliation(s)
- Lianne E M Vriend
- Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
| | - Przemek M Krawczyk
- Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands.
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80
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DNA damage repair in breast cancer and its therapeutic implications. Pathology 2016; 49:156-165. [PMID: 28034453 DOI: 10.1016/j.pathol.2016.11.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 10/06/2016] [Accepted: 11/02/2016] [Indexed: 11/23/2022]
Abstract
The DNA damage response (DDR) involves the activation of numerous cellular activities that repair DNA lesions and maintain genomic integrity, and is critical in preventing tumorigenesis. Inherited or acquired mutations in specific genes involved in the DNA damage response, for example the breast cancer susceptibility genes 1/2 (BRCA1/2), phosphatase and tensin homolog (PTEN) and P53 are associated with various subtypes of breast cancer. Such changes can render breast cancer cells particularly sensitive to specific DNA damage response inhibitors, for example BRCA1/2 germline mutated cells are sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. The aims of this review are to discuss specific DNA damage response defects in breast cancer and to present the current stage of development of various DDR inhibitors (namely PARP, ATM/ATR, DNA-PK, PARG, RECQL5, FEN1 and APE1) for breast cancer mono- and combination therapy.
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81
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Saini KS, Hamidullah, Ashraf R, Mandalapu D, Das S, Siddiqui MQ, Dwivedi S, Sarkar J, Sharma VL, Konwar R. New orally active DNA minor groove binding small molecule CT-1 acts against breast cancer by targeting tumor DNA damage leading to p53-dependent apoptosis. Mol Carcinog 2016; 56:1266-1280. [DOI: 10.1002/mc.22588] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 10/31/2016] [Accepted: 11/02/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Karan Singh Saini
- Division of Endocrinology; CSIR-Central Drug Research Institute; Lucknow India
| | - Hamidullah
- Division of Endocrinology; CSIR-Central Drug Research Institute; Lucknow India
| | - Raghib Ashraf
- Division of Biochemistry; CSIR-Central Drug Research Institute; Lucknow India
| | - Dhanaraju Mandalapu
- Medicinal & Process Chemistry Division; CSIR-Central Drug Research Institute; Lucknow India
| | - Sharmistha Das
- Division of Endocrinology; CSIR-Central Drug Research Institute; Lucknow India
| | - Mohd Quadir Siddiqui
- Advanced Centre for Treatment; Research and Education in Cancer, Kharghar, Navi Mumbai; Maharashtra India
| | - Sonam Dwivedi
- Division of Endocrinology; CSIR-Central Drug Research Institute; Lucknow India
| | - Jayanta Sarkar
- Division of Biochemistry; CSIR-Central Drug Research Institute; Lucknow India
- Academy of Scientific and Innovative Research (AcSIR); New Delhi India
| | - Vishnu Lal Sharma
- Medicinal & Process Chemistry Division; CSIR-Central Drug Research Institute; Lucknow India
- Academy of Scientific and Innovative Research (AcSIR); New Delhi India
| | - Rituraj Konwar
- Division of Endocrinology; CSIR-Central Drug Research Institute; Lucknow India
- Academy of Scientific and Innovative Research (AcSIR); New Delhi India
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82
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Liberio MS, Sadowski MC, Davis RA, Rockstroh A, Vasireddy R, Lehman ML, Nelson CC. The ascidian natural product eusynstyelamide B is a novel topoisomerase II poison that induces DNA damage and growth arrest in prostate and breast cancer cells. Oncotarget 2016; 6:43944-63. [PMID: 26733491 PMCID: PMC4791278 DOI: 10.18632/oncotarget.6267] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 10/08/2015] [Indexed: 12/25/2022] Open
Abstract
As part of an anti-cancer natural product drug discovery program, we recently identified eusynstyelamide B (EB), which displayed cytotoxicity against MDA-MB-231 breast cancer cells (IC50 = 5 μM) and induced apoptosis. Here, we investigated the mechanism of action of EB in cancer cell lines of the prostate (LNCaP) and breast (MDA-MB-231). EB inhibited cell growth (IC50 = 5 μM) and induced a G2 cell cycle arrest, as shown by a significant increase in the G2/M cell population in the absence of elevated levels of the mitotic marker phospho-histone H3. In contrast to MDA-MB-231 cells, EB did not induce cell death in LNCaP cells when treated for up to 10 days. Transcript profiling and Ingenuity Pathway Analysis suggested that EB activated DNA damage pathways in LNCaP cells. Consistent with this, CHK2 phosphorylation was increased, p21CIP1/WAF1 was up-regulated and CDC2 expression strongly reduced by EB. Importantly, EB caused DNA double-strand breaks, yet did not directly interact with DNA. Analysis of topoisomerase II-mediated decatenation discovered that EB is a novel topoisomerase II poison.
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Affiliation(s)
- Michelle S Liberio
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, Queensland University of Technology, Princess Alexandra Hospital, Translational Research Institute, Brisbane, Queensland, Australia.,Eskitis Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| | - Martin C Sadowski
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, Queensland University of Technology, Princess Alexandra Hospital, Translational Research Institute, Brisbane, Queensland, Australia
| | - Rohan A Davis
- Eskitis Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| | - Anja Rockstroh
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, Queensland University of Technology, Princess Alexandra Hospital, Translational Research Institute, Brisbane, Queensland, Australia
| | - Raj Vasireddy
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, Queensland University of Technology, Princess Alexandra Hospital, Translational Research Institute, Brisbane, Queensland, Australia
| | - Melanie L Lehman
- Vancouver Prostate Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Colleen C Nelson
- Australian Prostate Cancer Research Centre - Queensland, Institute of Health and Biomedical Innovation, Queensland University of Technology, Princess Alexandra Hospital, Translational Research Institute, Brisbane, Queensland, Australia
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83
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Papa A, Caruso D, Strudel M, Tomao S, Tomao F. Update on Poly-ADP-ribose polymerase inhibition for ovarian cancer treatment. J Transl Med 2016; 14:267. [PMID: 27634150 PMCID: PMC5024442 DOI: 10.1186/s12967-016-1027-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 09/05/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Despite standard treatment for epithelial ovarian cancer (EOC), that involves cytoreductive surgery followed by platinum-based chemotherapy, and initial high response rates to these, up to 80 % of patients experience relapses with a median progression-free survival of 12-18 months. There remains an urgent need for novel targeted therapies to improve clinical outcomes in ovarian cancer. Of the many targeted therapies currently under evaluation, the most promising strategies developed thus far are antiangiogenic agents and Poly(ADP-ribose) polymerase (PARP) inhibitors. Particularly, PARP inhibitors are active in cells that have impaired repair of DNA by the homologous recombination (HR) pathway. Cells with mutated breast related cancer antigens (BRCA) function have HR deficiency, which is also present in a significant proportion of non-BRCA-mutated ovarian cancer ("BRCAness" ovarian cancer). The prevalence of germline BRCA mutations in EOC has historically been estimated to be around 10-15 %. However, recent reports suggest that this may be a gross underestimate, especially in women with high-grade serous ovarian cancer (HGSOC). The emergence of the DNA repair pathway as a rational target in various cancers led to the development of the PARP inhibitors. The concept of tumor-selective synthetic lethality heralded the beginning of an eventful decade, culminating in the approval by regulatory authorities both in Europe as a maintenance therapy and in the United States treatment for advanced recurrent disease of the first oral PARP inhibitor, olaparib, for the treatment of BRCA-mutated ovarian cancer patients. Other PARP inhibitors are clearly effective in this disease and, within the next years, the results of ongoing randomized trials will clarify their respective roles. CONCLUSION This review will discuss the different PARP inhibitors in development and the potential use of this class of agents in the future. Moreover, combination strategies involving PARP inhibitors are likely to receive increasing attention. The utility of PARP inhibitors combined with cytotoxic chemotherapy is of doubtful value, because of enhanced toxicity of this combination; while, more promising strategies include the combination with antiangiogenic agents, or with inhibitors of the P13K/AKT pathway and new generation of immunotherapy.
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Affiliation(s)
- Anselmo Papa
- Oncology Unit, Department of Medico-Surgical Sciences and Biotechnologies, University of Rome “Sapienza”, Latina, Italy
| | - Davide Caruso
- Oncology Unit, Department of Medico-Surgical Sciences and Biotechnologies, University of Rome “Sapienza”, Latina, Italy
| | - Martina Strudel
- Oncology Unit, Department of Medico-Surgical Sciences and Biotechnologies, University of Rome “Sapienza”, Latina, Italy
| | - Silverio Tomao
- Oncology Unit, Department of Radiological Sciences, Oncology and Pathology, University of Rome “Sapienza”, Latina, Italy
| | - Federica Tomao
- Department of Gynaecology and Obstetrics, University of Rome “Sapienza”, Policlinico “Umberto I”, Rome, Italy
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84
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Gewirtz DA, Alotaibi M, Yakovlev VA, Povirk LF. Tumor Cell Recovery from Senescence Induced by Radiation with PARP Inhibition. Radiat Res 2016; 186:327-332. [PMID: 27588595 DOI: 10.1667/rr14437.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Inhibitors of poly(ADP-ribose) polymerase (PARP) are clinically used as single-agent therapy for tumors with BRCA1 or BRCA2 mutations. One approach to expanding the use of PARP inhibitors to a wider range of tumors is to combine them with cytotoxic chemotherapy or radiotherapy. Preclinical studies in experimental animals and tumor cells in culture indicate that PARP inhibition modestly sensitizes most tumor cells to ionizing radiation. Studies of cell behavior after these combined treatments show that radiosensitization is manifested predominantly in an increase in prolonged growth arrest and senescence, with little or no contribution from apoptosis. The secretory phenotype associated with senescence can target these tumor cells for immune surveillance, and therefore increased senescence can effectively contribute to tumor control. However, the possible recovery of senescent cells and re-entry into cell cycle after prolonged arrest also needs to be considered. Such recovery could lead to tumor recurrence, yet may not be reflected in short-term assays commonly used to assess radiosensitization.
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Affiliation(s)
| | - Moureq Alotaibi
- Department of a Pharmacology, Toxicology and Medicine and.,c College of Pharmacy, King Saud University, Riyadh 11451, Kingdom of Saudi Arabia
| | - Vasily A Yakovlev
- b Radiation Oncology, Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia 23298; and
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85
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Moureau S, Luessing J, Harte EC, Voisin M, Lowndes NF. A role for the p53 tumour suppressor in regulating the balance between homologous recombination and non-homologous end joining. Open Biol 2016; 6:rsob.160225. [PMID: 27655732 PMCID: PMC5043586 DOI: 10.1098/rsob.160225] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 08/25/2016] [Indexed: 12/24/2022] Open
Abstract
Loss of p53, a transcription factor activated by cellular stress, is a frequent event in cancer. The role of p53 in tumour suppression is largely attributed to cell fate decisions. Here, we provide evidence supporting a novel role for p53 in the regulation of DNA double-strand break (DSB) repair pathway choice. 53BP1, another tumour suppressor, was initially identified as p53 Binding Protein 1, and has been shown to inhibit DNA end resection, thereby stimulating non-homologous end joining (NHEJ). Yet another tumour suppressor, BRCA1, reciprocally promotes end resection and homologous recombination (HR). Here, we show that in both human and mouse cells, the absence of p53 results in impaired 53BP1 focal recruitment to sites of DNA damage induced by ionizing radiation. This effect is largely independent of cell cycle phase and the extent of DNA damage. In p53-deficient cells, diminished localization of 53BP1 is accompanied by a reciprocal increase in BRCA1 recruitment to DSBs. Consistent with these findings, we demonstrate that DSB repair via NHEJ is abrogated, while repair via homology-directed repair (HDR) is stimulated. Overall, we propose that in addition to its role as an ‘effector’ protein in the DNA damage response, p53 plays a role in the regulation of DSB repair pathway choice.
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Affiliation(s)
- Sylvie Moureau
- Genome Stability Laboratory, Centre for Chromosome Biology and School of Natural Science, Biomedical Science Building, National University of Ireland Galway, Dangan, Ireland
| | - Janna Luessing
- Genome Stability Laboratory, Centre for Chromosome Biology and School of Natural Science, Biomedical Science Building, National University of Ireland Galway, Dangan, Ireland
| | - Emma Christina Harte
- Genome Stability Laboratory, Centre for Chromosome Biology and School of Natural Science, Biomedical Science Building, National University of Ireland Galway, Dangan, Ireland
| | - Muriel Voisin
- Genome Stability Laboratory, Centre for Chromosome Biology and School of Natural Science, Biomedical Science Building, National University of Ireland Galway, Dangan, Ireland
| | - Noel Francis Lowndes
- Genome Stability Laboratory, Centre for Chromosome Biology and School of Natural Science, Biomedical Science Building, National University of Ireland Galway, Dangan, Ireland
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86
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Mateo J, Boysen G, Barbieri CE, Bryant HE, Castro E, Nelson PS, Olmos D, Pritchard CC, Rubin MA, de Bono JS. DNA Repair in Prostate Cancer: Biology and Clinical Implications. Eur Urol 2016; 71:417-425. [PMID: 27590317 DOI: 10.1016/j.eururo.2016.08.037] [Citation(s) in RCA: 152] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 08/12/2016] [Indexed: 10/21/2022]
Abstract
CONTEXT For more precise, personalized care in prostate cancer (PC), a new classification based on molecular features relevant for prognostication and treatment stratification is needed. Genomic aberrations in the DNA damage repair pathway are common in PC, particularly in late-stage disease, and may be relevant for treatment stratification. OBJECTIVE To review current knowledge on the prevalence and clinical significance of aberrations in DNA repair genes in PC, particularly in metastatic disease. EVIDENCE ACQUISITION A literature search up to July 2016 was conducted, including clinical trials and preclinical basic research studies. Keywords included DNA repair, BRCA, ATM, CRPC, prostate cancer, PARP, platinum, predictive biomarkers, and hereditary cancer. EVIDENCE SYNTHESIS We review how the DNA repair pathway is relevant to prostate carcinogenesis and progression. Data on how this may be relevant to hereditary cancer and genetic counseling are included, as well as data from clinical trials of PARP inhibitors and platinum therapeutics in PC. CONCLUSIONS Relevant studies have identified genomic defects in DNA repair in PCs in 20-30% of advanced castration-resistant PC cases, a proportion of which are germline aberrations and heritable. Phase 1/2 clinical trial data, and other supporting clinical data, support the development of PARP inhibitors and DNA-damaging agents in this molecularly defined subgroup of PC following success in other cancer types. These studies may be an opportunity to improve patient care with personalized therapeutic strategies. PATIENT SUMMARY Key literature on how genomic defects in the DNA damage repair pathway are relevant for prostate cancer biology and clinical management is reviewed. Potential implications for future changes in patient care are discussed.
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Affiliation(s)
- Joaquin Mateo
- Division of Cancer Therapeutics and Division of Clinical Studies, The Institute of Cancer Research, London, UK; Drug Development Unit, The Royal Marsden NHS Foundation Trust, London, UK
| | - Gunther Boysen
- Division of Cancer Therapeutics and Division of Clinical Studies, The Institute of Cancer Research, London, UK
| | - Christopher E Barbieri
- Department of Urology, Weill Cornell Medicine, New York, NY, USA; Caryl and Israel Englander Institute for Precision Medicine, New York Presbyterian Hospital-Weill Cornell Medicine. New York, NY, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - Helen E Bryant
- Sheffield Institute for Nucleic Acids, Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
| | - Elena Castro
- Prostate Cancer Unit, Spanish National Cancer Research Centre, Madrid, Spain
| | - Pete S Nelson
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA; Divisions of Human Biology and Clinical Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA
| | - David Olmos
- Prostate Cancer Unit, Spanish National Cancer Research Centre, Madrid, Spain; Medical Oncology Department, CNIO-IBIMA Genitourinary Cancer Unit, Hospital Virgen de la Victoria and Hospital Regional de Malaga, Malaga, Spain
| | - Colin C Pritchard
- Department of Laboratory Medicine, University of Washington, Seattle, WA, USA
| | - Mark A Rubin
- Caryl and Israel Englander Institute for Precision Medicine, New York Presbyterian Hospital-Weill Cornell Medicine. New York, NY, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA; Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, USA
| | - Johann S de Bono
- Division of Cancer Therapeutics and Division of Clinical Studies, The Institute of Cancer Research, London, UK; Drug Development Unit, The Royal Marsden NHS Foundation Trust, London, UK.
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87
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Low doses of X-rays induce prolonged and ATM-independent persistence of γH2AX foci in human gingival mesenchymal stem cells. Oncotarget 2016; 6:27275-87. [PMID: 26314960 PMCID: PMC4694989 DOI: 10.18632/oncotarget.4739] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 07/10/2015] [Indexed: 12/11/2022] Open
Abstract
Diagnostic imaging delivering low doses of radiation often accompany human mesenchymal stem cells (MSCs)-based therapies. However, effects of low dose radiation on MSCs are poorly characterized. Here we examine patterns of phosphorylated histone H2AX (γH2AX) and phospho-S1981 ATM (pATM) foci formation in human gingiva-derived MSCs exposed to X-rays in time-course and dose-response experiments. Both γH2AX and pATM foci accumulated linearly with dose early after irradiation (5–60 min), with a maximum induction observed at 30–60 min (37 ± 3 and 32 ± 3 foci/cell/Gy for γH2AX and pATM, respectively). The number of γH2AX foci produced by intermediate doses (160 and 250 mGy) significantly decreased (40–60%) between 60 and 240 min post-irradiation, indicating rejoining of DNA double-strand breaks. In contrast, γH2AX foci produced by low doses (20–80 mGy) did not change after 60 min. The number of pATM foci between 60 and 240 min decreased down to control values in a dose-independent manner. Similar kinetics was observed for pATM foci co-localized with γH2AX foci. Collectively, our results suggest differential DNA double-strand break signaling and processing in response to low vs. intermediate doses of X-rays in human MSCs. Furthermore, mechanisms governing the prolonged persistence of γH2AX foci in these cells appear to be ATM-independent.
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88
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Root H, Larsen A, Komosa M, Al-Azri F, Li R, Bazett-Jones DP, Stephen Meyn M. FANCD2 limits BLM-dependent telomere instability in the alternative lengthening of telomeres pathway. Hum Mol Genet 2016; 25:3255-3268. [DOI: 10.1093/hmg/ddw175] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 05/02/2016] [Accepted: 06/06/2016] [Indexed: 11/12/2022] Open
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89
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Getting Ready for the Dance: FANCJ Irons Out DNA Wrinkles. Genes (Basel) 2016; 7:genes7070031. [PMID: 27376332 PMCID: PMC4962001 DOI: 10.3390/genes7070031] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 06/13/2016] [Accepted: 06/27/2016] [Indexed: 12/21/2022] Open
Abstract
Mounting evidence indicates that alternate DNA structures, which deviate from normal double helical DNA, form in vivo and influence cellular processes such as replication and transcription. However, our understanding of how the cellular machinery deals with unusual DNA structures such as G-quadruplexes (G4), triplexes, or hairpins is only beginning to emerge. New advances in the field implicate a direct role of the Fanconi Anemia Group J (FANCJ) helicase, which is linked to a hereditary chromosomal instability disorder and important for cancer suppression, in replication past unusual DNA obstacles. This work sets the stage for significant progress in dissecting the molecular mechanisms whereby replication perturbation by abnormal DNA structures leads to genomic instability. In this review, we focus on FANCJ and its role to enable efficient DNA replication when the fork encounters vastly abundant naturally occurring DNA obstacles, which may have implications for targeting rapidly dividing cancer cells.
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90
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Whelan DR, Yin Y, Bermudez-Hernandez K, Keegan S, Fenyö D, Rothenberg E. Single Molecule Localization Microscopy of DNA Damage Response Pathways in Cancer. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2016; 22:1016-1017. [PMID: 28239291 PMCID: PMC5322745 DOI: 10.1017/s1431927616005924] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- Donna R Whelan
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Yandong Yin
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Keria Bermudez-Hernandez
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Sarah Keegan
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - David Fenyö
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
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91
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Vriend LEM, Prakash R, Chen CC, Vanoli F, Cavallo F, Zhang Y, Jasin M, Krawczyk PM. Distinct genetic control of homologous recombination repair of Cas9-induced double-strand breaks, nicks and paired nicks. Nucleic Acids Res 2016; 44:5204-17. [PMID: 27001513 PMCID: PMC4914091 DOI: 10.1093/nar/gkw179] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 03/05/2016] [Accepted: 03/07/2016] [Indexed: 12/29/2022] Open
Abstract
DNA double-strand breaks (DSBs) are known to be powerful inducers of homologous recombination (HR), but single-strand breaks (nicks) have also been shown to trigger HR. Both DSB- and nick-induced HR ((nick)HR) are exploited in advanced genome-engineering approaches based on the bacterial RNA-guided nuclease Cas9. However, the mechanisms of (nick)HR are largely unexplored. Here, we applied Cas9 nickases to study (nick)HR in mammalian cells. We find that (nick)HR is unaffected by inhibition of major damage signaling kinases and that it is not suppressed by nonhomologous end-joining (NHEJ) components, arguing that nick processing does not require a DSB intermediate to trigger HR. Relative to a single nick, nicking both strands enhances HR, consistent with a DSB intermediate, even when nicks are induced up to ∼1kb apart. Accordingly, HR and NHEJ compete for repair of these paired nicks, but, surprisingly, only when 5' overhangs or blunt ends can be generated. Our study advances the understanding of molecular mechanisms driving nick and paired-nick repair in mammalian cells and clarify phenomena associated with Cas9-mediated genome editing.
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Affiliation(s)
- Lianne E M Vriend
- Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, Amsterdam, 1105 AZ, The Netherlands Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Rohit Prakash
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Chun-Chin Chen
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA Weill Cornell Graduate School of Medical Sciences, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Fabio Vanoli
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Francesca Cavallo
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Yu Zhang
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Maria Jasin
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA Weill Cornell Graduate School of Medical Sciences, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Przemek M Krawczyk
- Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, Amsterdam, 1105 AZ, The Netherlands Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
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92
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Tsai RYL. Balancing self-renewal against genome preservation in stem cells: How do they manage to have the cake and eat it too? Cell Mol Life Sci 2016; 73:1803-23. [PMID: 26886024 PMCID: PMC5040593 DOI: 10.1007/s00018-016-2152-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 01/18/2016] [Accepted: 01/28/2016] [Indexed: 01/22/2023]
Abstract
Stem cells are endowed with the awesome power of self-renewal and multi-lineage differentiation that allows them to be major contributors to tissue homeostasis. Owing to their longevity and self-renewal capacity, they are also faced with a higher risk of genomic damage compared to differentiated cells. Damage on the genome, if not prevented or repaired properly, will threaten the survival of stem cells and culminate in organ failure, premature aging, or cancer formation. It is therefore of paramount importance that stem cells remain genomically stable throughout life. Given their unique biological and functional requirement, stem cells are thought to manage genotoxic stress somewhat differently from non-stem cells. The focus of this article is to review the current knowledge on how stem cells escape the barrage of oxidative and replicative DNA damage to stay in self-renewal. A clear statement on this subject should help us better understand tissue regeneration, aging, and cancer.
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Affiliation(s)
- Robert Y L Tsai
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University Health Science Center, 2121 W. Holcombe Blvd, Houston, TX, 77030, USA.
- Department of Molecular and Cellular Medicine, Texas A&M University Health Science Center, College Station, TX, 77843, USA.
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93
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Abstract
Loss of function or mutation of the ataxia-telangiectasia mutated gene product (ATM) results in inherited genetic disorders characterized by neurodegeneration, immunodeficiency, and cancer. Ataxia-telangiectasia mutated (ATM) gene product belongs to the PI3K-like protein kinase (PIKKs) family and is functionally implicated in mitogenic signal transduction, chromosome condensation, meiotic recombination, cell-cycle control, and telomere maintenance. The ATM protein kinase is primarily activated in response to DNA double strand breaks (DSBs), the most deleterious form of DNA damage produced by ionizing radiation (IR) or radiomimetic drugs. It is detected at DNA damage sites, where ATM autophosphorylation causes dissociation of the inactive homodimeric form to the activated monomeric form. Interestingly, heat shock can activate ATM independent of the presence of DNA strand breaks. ATM is an integral part of the sensory machinery that detects DSBs during meiosis, mitosis, or DNA breaks mediated by free radicals. These DNA lesions can trigger higher order chromatin reorganization fuelled by posttranslational modifications of histones and histone binding proteins. Our group, and others, have shown that ATM activation is tightly regulated by chromatin modifications. This review summarizes the multiple approaches used to discern the role of ATM and other associated proteins in chromatin modification in response to DNA damage.
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94
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Sakasai R, Iwabuchi K. The distinctive cellular responses to DNA strand breaks caused by a DNA topoisomerase I poison in conjunction with DNA replication and RNA transcription. Genes Genet Syst 2015; 90:187-94. [PMID: 26616758 DOI: 10.1266/ggs.15-00023] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Camptothecin (CPT) inhibits DNA topoisomerase I (Top1) through a non-catalytic mechanism that stabilizes the Top1-DNA cleavage complex (Top1cc) and blocks the DNA re-ligation step, resulting in the accumulation in the genome of DNA single-strand breaks (SSBs), which are converted to secondary strand breaks when they collide with the DNA replication and RNA transcription machinery. DNA strand breaks mediated by replication, which have one DNA end, are distinct in repair from the DNA double-strand breaks (DSBs) that have two ends and are caused by ionizing radiation and other agents. In contrast to two-ended DSBs, such one-ended DSBs are preferentially repaired through the homologous recombination pathway. Conversely, the repair of one-ended DSBs by the non-homologous end-joining pathway is harmful for cells and leads to cell death. The choice of repair pathway has a crucial impact on cell fate and influences the efficacy of anticancer drugs such as CPT derivatives. In addition to replication-mediated one-ended DSBs, transcription also generates DNA strand breaks upon collision with the Top1cc. Some reports suggest that transcription-mediated DNA strand breaks correlate with neurodegenerative diseases. However, the details of the repair mechanisms of, and cellular responses to, transcription-mediated DNA strand breaks still remain unclear. In this review, combining our recent results and those of previous reports, we introduce and discuss the responses to CPT-induced DNA damage mediated by DNA replication and RNA transcription.
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Affiliation(s)
- Ryo Sakasai
- Department of Biochemistry I, Kanazawa Medical University
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95
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Catalytic strand separation by RECQ1 is required for RPA-mediated response to replication stress. Curr Biol 2015; 25:2830-2838. [PMID: 26455304 DOI: 10.1016/j.cub.2015.09.026] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 08/19/2015] [Accepted: 09/09/2015] [Indexed: 11/21/2022]
Abstract
Three (BLM, WRN, and RECQ4) of the five human RecQ helicases are linked to genetic disorders characterized by genomic instability, cancer, and accelerated aging [1]. RECQ1, the first human RecQ helicase discovered [2-4] and the most abundant [5], was recently implicated in breast cancer [6, 7]. RECQ1 is an ATP-dependent DNA-unwinding enzyme (helicase) [8, 9] with roles in replication [10-12] and DNA repair [13-16]. RECQ1 is highly expressed in various tumors and cancer cell lines (for review, see [17]), and its suppression reduces cancer cell proliferation [14], suggesting a target for anti-cancer drugs. RECQ1's assembly state plays a critical role in modulating its helicase, branch migration (BM), or strand annealing [18, 19]. The crystal structure of truncated RECQ1 [20, 21] resembles that of E. coli RecQ [22] with two RecA-like domains, a RecQ-specific zinc-binding domain and a winged-helix domain, the latter implicated in DNA strand separation and oligomer formation. In addition, a conserved aromatic loop (AL) is important for DNA unwinding by bacterial RecQ [23, 24] and truncated RECQ1 helicases [21]. To better understand the roles of RECQ1, two AL mutants (W227A and F231A) in full-length RECQ1 were characterized biochemically and genetically. The RECQ1 mutants were defective in helicase or BM but retained DNA binding, oligomerization, ATPase, and strand annealing. RECQ1-depleted HeLa cells expressing either AL mutant displayed reduced replication tract length, elevated dormant origin firing, and increased double-strand breaks that could be suppressed by exogenously expressed replication protein A (RPA). Thus, RECQ1 governs RPA's availability in order to maintain normal replication dynamics, suppress DNA damage, and preserve genome homeostasis.
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96
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Yang Y, Liu Z, Wang F, Temviriyanukul P, Ma X, Tu Y, Lv L, Lin YF, Huang M, Zhang T, Pei H, Chen BPC, Jansen JG, de Wind N, Fischhaber PL, Friedberg EC, Tang TS, Guo C. FANCD2 and REV1 cooperate in the protection of nascent DNA strands in response to replication stress. Nucleic Acids Res 2015; 43:8325-39. [PMID: 26187992 PMCID: PMC4787816 DOI: 10.1093/nar/gkv737] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 07/08/2015] [Indexed: 12/12/2022] Open
Abstract
REV1 is a eukaryotic member of the Y-family of DNA polymerases involved in translesion DNA synthesis and genome mutagenesis. Recently, REV1 is also found to function in homologous recombination. However, it remains unclear how REV1 is recruited to the sites where homologous recombination is processed. Here, we report that loss of mammalian REV1 results in a specific defect in replication-associated gene conversion. We found that REV1 is targeted to laser-induced DNA damage stripes in a manner dependent on its ubiquitin-binding motifs, on RAD18, and on monoubiquitinated FANCD2 (FANCD2-mUb) that associates with REV1. Expression of a FANCD2-Ub chimeric protein in RAD18-depleted cells enhances REV1 assembly at laser-damaged sites, suggesting that FANCD2-mUb functions downstream of RAD18 to recruit REV1 to DNA breaks. Consistent with this suggestion we found that REV1 and FANCD2 are epistatic with respect to sensitivity to the double-strand break-inducer camptothecin. REV1 enrichment at DNA damage stripes also partially depends on BRCA1 and BRCA2, components of the FANCD2/BRCA supercomplex. Intriguingly, analogous to FANCD2-mUb and BRCA1/BRCA2, REV1 plays an unexpected role in protecting nascent replication tracts from degradation by stabilizing RAD51 filaments. Collectively these data suggest that REV1 plays multiple roles at stalled replication forks in response to replication stress.
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Affiliation(s)
- Yeran Yang
- Key Laboratory of Genomics and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhenbo Liu
- Key Laboratory of Genomics and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Fengli Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Piya Temviriyanukul
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Xiaolu Ma
- Key Laboratory of Genomics and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yingfeng Tu
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Lingna Lv
- Key Laboratory of Genomics and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yu-Fen Lin
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Min Huang
- Key Laboratory of Genomics and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Ting Zhang
- Key Laboratory of Genomics and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Huadong Pei
- Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Benjamin P C Chen
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jacob G Jansen
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Niels de Wind
- Department of Human Genetics, Leiden University Medical Center, 2300 RC, Leiden, The Netherlands
| | - Paula L Fischhaber
- Department of Chemistry and Biochemistry, California State University Northridge, Northridge, CA 91330-8262, USA
| | - Errol C Friedberg
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Caixia Guo
- Key Laboratory of Genomics and Precision Medicine, China Gastrointestinal Cancer Research Center, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
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97
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Yélamos J, Galindo M, Navarro J, Albanell J, Rovira A, Rojo F, Oliver J. Enhancing tumor-targeting monoclonal antibodies therapy by PARP inhibitors. Oncoimmunology 2015; 5:e1065370. [PMID: 26942084 DOI: 10.1080/2162402x.2015.1065370] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 06/16/2015] [Accepted: 06/17/2015] [Indexed: 12/17/2022] Open
Abstract
Monoclonal antibodies (mAbs) have become a successful therapeutic approach in cancer. However, some patients do not achieve long-term clinical benefit and most mAbs only exert modest effects as monotherapies. Therefore, combinations with chemotherapy are currently being investigated. Emerging studies have shown a synergistic therapeutic effect of PARP inhibitors and mAbs in cancer. PARP enzymes catalytically cleave β-NAD+ and transfer the ADP-ribose moiety to acceptor proteins, modifying their function. In here, we update recent data about the therapeutic effect of the combination of PARP inhibitors with mAbs in cancer treatment and discuss the molecular mechanisms involved in this synergy.
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Affiliation(s)
- José Yélamos
- Cancer Research Program, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain; Department of Immunology, Hospital del Mar, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain
| | - Miguel Galindo
- Cancer Research Program, Hospital del Mar Medical Research Institute (IMIM) , Barcelona, Spain
| | - Judith Navarro
- Cancer Research Program, Hospital del Mar Medical Research Institute (IMIM) , Barcelona, Spain
| | - Joan Albanell
- Cancer Research Program, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain; Department of Oncology, Hospital del Mar, Barcelona, Spain
| | - Ana Rovira
- Cancer Research Program, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain; Department of Oncology, Hospital del Mar, Barcelona, Spain
| | - Federico Rojo
- Cancer Research Program, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain; Department of Patology, IIS Fundación Jiménez Díaz, Madrid, Spain
| | - Javier Oliver
- Department of Cell Biology and Immunology; Instituto de Parasitología y Biomedicina López Neyra , Granada, Spain
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98
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Malyuchenko NV, Kotova EY, Kulaeva OI, Kirpichnikov MP, Studitskiy VM. PARP1 Inhibitors: antitumor drug design. Acta Naturae 2015; 7:27-37. [PMID: 26483957 PMCID: PMC4610162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
The poly (ADP-ribose) polymerase 1 (PARP1) enzyme is one of the promising molecular targets for the discovery of antitumor drugs. PARP1 is a common nuclear protein (1-2 million molecules per cell) serving as a "sensor" for DNA strand breaks. Increased PARP1 expression is sometimes observed in melanomas, breast cancer, lung cancer, and other neoplastic diseases. The PARP1 expression level is a prognostic indicator and is associated with a poor survival prognosis. There is evidence that high PARP1 expression and treatment-resistance of tumors are correlated. PARP1 inhibitors are promising antitumor agents, since they act as chemo- and radiosensitizers in the conventional therapy of malignant tumors. Furthermore, PARP1 inhibitors can be used as independent, effective drugs against tumors with broken DNA repair mechanisms. Currently, third-generation PARP1 inhibitors are being developed, many of which are undergoing Phase II clinical trials. In this review, we focus on the properties and features of the PARP1 inhibitors identified in preclinical and clinical trials. We also describe some problems associated with the application of PARP1 inhibitors. The possibility of developing new PARP1 inhibitors aimed at DNA binding and transcriptional activity rather than the catalytic domain of the protein is discussed.
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Affiliation(s)
- N. V. Malyuchenko
- Lomonosov Moscow State University, Leninskie Gory, 1/12, Moscow, 119991, Russia
| | - E. Yu. Kotova
- Fox Chase Cancer Center, Philadelphia, PA, 19111-2497, USA
| | - O. I. Kulaeva
- Lomonosov Moscow State University, Leninskie Gory, 1/12, Moscow, 119991, Russia
- Fox Chase Cancer Center, Philadelphia, PA, 19111-2497, USA
| | - M. P. Kirpichnikov
- Lomonosov Moscow State University, Leninskie Gory, 1/12, Moscow, 119991, Russia
| | - V. M. Studitskiy
- Lomonosov Moscow State University, Leninskie Gory, 1/12, Moscow, 119991, Russia
- Fox Chase Cancer Center, Philadelphia, PA, 19111-2497, USA
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99
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Ninomiya Y, Cui X, Yasuda T, Wang B, Yu D, Sekine-Suzuki E, Nenoi M. Arsenite induces premature senescence via p53/p21 pathway as a result of DNA damage in human malignant glioblastoma cells. BMB Rep 2015; 47:575-80. [PMID: 24499675 PMCID: PMC4261516 DOI: 10.5483/bmbrep.2014.47.10.254] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Indexed: 01/17/2023] Open
Abstract
In this study, we investigate whether arsenite-induced DNA damage leads to p53-dependent premature senescence using human glioblastoma cells with p53-wild type (U87MG-neo) and p53 deficient (U87MG-E6). A dose dependent relationship between arsenite and reduced cell growth is demonstrated, as well as induced γH2AX foci formation in both U87MG-neo and U87MG-E6 cells at low concentrations of arsenite. Senescence was induced by arsenite with senescence-associated β-galactosidase staining. Dimethyl- and trimethyl-lysine 9 of histone H3 (H3DMK9 and H3TMK9) foci formation was accompanied by p21 accumulation only in U87MG-neo but not in U87MG-E6 cells. This suggests that arsenite induces premature senescence as a result of DNA damage with heterochromatin forming through a p53/p21 dependent pathway. p21 and p53 siRNA consistently decreased H3TMK9 foci formation in U87M G-neo but not in U87MG-E6 cells after arsenite treatment. Taken together, arsenite reduces cell growth independently of p53 and induces premature senescence via p53/p21-dependent pathway following DNA damage. [BMB Reports 2014; 47(10): 575-580]
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Affiliation(s)
- Yasuharu Ninomiya
- Radiation Risk Reduction Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba 263-8555, Japan
| | - Xing Cui
- Medical Physics Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba 263-8555, Japan
| | - Takeshi Yasuda
- Radiation Emergency Medicine Research Program, Research Center for Radiation Emergency Medicine, National Institute of Radiological Sciences, Chiba 263-8555, Japan
| | - Bing Wang
- Radiation Risk Reduction Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba 263-8555, Japan
| | - Dong Yu
- School of Radiological Medicine and Protection, Medical College of Soochow University, 199 Ren Ai Rd, Suzhou Industrial Park, Suzhou 215123, China
| | - Emiko Sekine-Suzuki
- Research Program for Application of Heavy ions and Medical Science, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba 263-8555, Japan
| | - Mitsuru Nenoi
- Radiation Risk Reduction Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, Chiba 263-8555, Japan
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Willers H, Gheorghiu L, Liu Q, Efstathiou JA, Wirth LJ, Krause M, von Neubeck C. DNA Damage Response Assessments in Human Tumor Samples Provide Functional Biomarkers of Radiosensitivity. Semin Radiat Oncol 2015; 25:237-50. [PMID: 26384272 DOI: 10.1016/j.semradonc.2015.05.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Predictive biomarkers are urgently needed for individualization of radiation therapy and treatment with radiosensitizing anticancer agents. Genomic profiling of human cancers provides us with unprecedented insight into the mutational landscape of genes directly or indirectly involved in the response to radiation-induced DNA damage. However, to what extent this wealth of structural information about the cancer genome produces biomarkers of sensitivity to radiation remains to be seen. Investigators are increasingly studying the subnuclear accumulation (ie, foci) of proteins in the DNA damage response (DDR), such as gamma-H2AX, 53BP1, or RAD51, as a surrogate of treatment sensitivity. Recent findings from preclinical studies have demonstrated the predictive potential of DDR foci by correlating foci with clinically relevant end points such as tumor control probability. Therefore, preclinical investigations of DDR foci responses are increasingly moving into cells and tissues from patients, which is the major focus of this review. The advantage of using DDR foci as functional biomarkers is that they can detect alterations in DNA repair due to various mechanisms. Moreover, they provide a global measurement of DDR network function without needing to know the identities of all the components, many of which remain unknown. Foci assays are thus expected to yield functional insight that may complement or supersede genomic information, thereby giving radiation oncologists unique opportunities to individualize cancer treatments in the near future.
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Affiliation(s)
- Henning Willers
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA.
| | - Liliana Gheorghiu
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA
| | - Qi Liu
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA
| | - Jason A Efstathiou
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA
| | - Lori J Wirth
- Department of Medicine, Massachusetts General Hospital, Boston, MA
| | - Mechthild Krause
- German Cancer Consortium (DKTK) Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany; Department of Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany; OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology, Germany
| | - Cläre von Neubeck
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany
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