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Gonzáles-Córdova RA, Dos Santos TR, Gachet-Castro C, Andrade Vieira J, Trajano-Silva LAM, Sakamoto-Hojo ET, Baqui MMA. Trypanosoma cruzi infection induces DNA double-strand breaks and activates DNA damage response pathway in host epithelial cells. Sci Rep 2024; 14:5225. [PMID: 38433244 PMCID: PMC10909859 DOI: 10.1038/s41598-024-53589-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 02/01/2024] [Indexed: 03/05/2024] Open
Abstract
Trypanosoma cruzi, the etiological agent of Chagas disease, invades many cell types affecting numerous host-signalling pathways. During the T. cruzi infection, we demonstrated modulations in the host RNA polymerase II activity with the downregulation of ribonucleoproteins affecting host transcription and splicing machinery. These alterations could be a result of the initial damage to the host DNA caused by the presence of the parasite, however, the mechanisms are not well understood. Herein, we examined whether infection by T. cruzi coincided with enhanced DNA damage in the host cell. We studied the engagement of the DNA damage response (DDR) pathways at the different time points (0-24 h post-infection, hpi) by T. cruzi in LLC-MK2 cells. In response to double-strand breaks (DSB), maximum phosphorylation of the histone variant H2AX is observed at 2hpi and promotes recruitment of the DDR p53-binding protein (53BP1). During T. cruzi infection, Ataxia-telangiectasia mutated protein (ATM) and DNA-PK protein kinases remained active in a time-dependent manner and played roles in regulating the host response to DSB. The host DNA lesions caused by the infection are likely orchestrated by the non-homologous end joining (NHEJ) pathway to maintain the host genome integrity.
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Affiliation(s)
- Raul Alexander Gonzáles-Córdova
- Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo-USP, Ribeirão Preto, 14049-900, Brazil
| | - Thamires Rossi Dos Santos
- Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo-USP, Ribeirão Preto, 14049-900, Brazil
| | - Camila Gachet-Castro
- Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo-USP, Ribeirão Preto, 14049-900, Brazil
| | - Johnathan Andrade Vieira
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo-USP, Ribeirão Preto, 14049-900, Brazil
| | - Lays Adrianne Mendonça Trajano-Silva
- Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo-USP, Ribeirão Preto, 14049-900, Brazil
| | - Elza Tiemi Sakamoto-Hojo
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo-USP, Ribeirão Preto, 14049-900, Brazil
- Department of Biology, Faculty of Philosophy Sciences and Letters at Ribeirão Preto, University of São Paulo, São Paulo, 14040-901, Brazil
| | - Munira Muhammad Abdel Baqui
- Department of Cellular and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School, University of São Paulo-USP, Ribeirão Preto, 14049-900, Brazil.
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2
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Paull TT, Woolley PR. A-T neurodegeneration and DNA damage-induced transcriptional stress. DNA Repair (Amst) 2024; 135:103647. [PMID: 38377644 DOI: 10.1016/j.dnarep.2024.103647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 02/08/2024] [Indexed: 02/22/2024]
Abstract
Loss of the ATM protein kinase in humans results in Ataxia-telangiectasia, a disorder characterized by childhood-onset neurodegeneration of the cerebellum as well as cancer predisposition and immunodeficiency. Although many aspects of ATM function are well-understood, the mechanistic basis of the progressive cerebellar ataxia that occurs in patients is not. Here we review recent progress related to the role of ATM in neurons and the cerebellum that comes from many sources: animal models, post-mortem brain tissue samples, and human neurons in culture. These observations have revealed new insights into the consequences of ATM loss on DNA damage, gene expression, and immune signaling in the brain. Many results point to the importance of reactive oxygen species as well as single-strand DNA breaks in the progression of molecular events leading to neuronal dysfunction. In addition, innate immunity signaling pathways appear to play a critical role in ATM functions in microglia, responding to various forms of nucleic acid sensors and regulating survival of neurons and other cell types. Overall, the results lead to an updated view of transcriptional stress and DNA damage resulting from ATM loss that results in changes in gene expression as well as neuroinflammation that contribute to the cerebellar neurodegeneration observed in patients.
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Affiliation(s)
- Tanya T Paull
- The University of Texas at Austin, Department of Molecular Biosciences, Austin, TX 78712, USA.
| | - Phillip R Woolley
- The University of Texas at Austin, Department of Molecular Biosciences, Austin, TX 78712, USA
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3
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Li S, Liu B, Tan M, Juillard F, Szymula A, Álvarez Á, Van Sciver N, George A, Ramachandran A, Raina K, Tumuluri VS, Costa C, Simas J, Kaye K. Kaposi's sarcoma herpesvirus exploits the DNA damage response to circularize its genome. Nucleic Acids Res 2024; 52:1814-1829. [PMID: 38180827 PMCID: PMC10899755 DOI: 10.1093/nar/gkad1224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/05/2023] [Accepted: 12/16/2023] [Indexed: 01/07/2024] Open
Abstract
To establish lifelong, latent infection, herpesviruses circularize their linear, double-stranded, DNA genomes through an unknown mechanism. Kaposi's sarcoma (KS) herpesvirus (KSHV), a gamma herpesvirus, is tightly linked with KS, primary effusion lymphoma, and multicentric Castleman's disease. KSHV persists in latently infected cells as a multi-copy, extrachromosomal episome. Here, we show the KSHV genome rapidly circularizes following infection, and viral protein expression is unnecessary for this process. The DNA damage response (DDR) kinases, ATM and DNA-PKcs, each exert roles, and absence of both severely compromises circularization and latency. These deficiencies were rescued by expression of ATM and DNA-PKcs, but not catalytically inactive mutants. In contrast, γH2AX did not function in KSHV circularization. The linear viral genomic ends resemble a DNA double strand break, and non-homologous DNA end joining (NHEJ) and homologous recombination (HR) reporters indicate both NHEJ and HR contribute to KSHV circularization. Last, we show, similar to KSHV, ATM and DNA-PKcs have roles in circularization of the alpha herpesvirus, herpes simplex virus-1 (HSV-1), while γH2AX does not. Therefore, the DDR mediates KSHV and HSV-1 circularization. This strategy may serve as a general herpesvirus mechanism to initiate latency, and its disruption may provide new opportunities for prevention of herpesvirus disease.
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Affiliation(s)
- Shijun Li
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Bing Liu
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Min Tan
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Franceline Juillard
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Agnieszka Szymula
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Ángel L Álvarez
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Nicholas Van Sciver
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Athira George
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Akshaya Ramachandran
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Komal Raina
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Vinayak Sadasivam Tumuluri
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
| | - Catarina N Costa
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028 Lisboa, Portugal
- Universidade Católica Portuguesa, Católica Medical School, Católica Biomedical Research, Palma de Cima, 1649-023 Lisboa, Portugal
| | - J Pedro Simas
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028 Lisboa, Portugal
- Universidade Católica Portuguesa, Católica Medical School, Católica Biomedical Research, Palma de Cima, 1649-023 Lisboa, Portugal
| | - Kenneth M Kaye
- Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
- Program in Virology, Harvard Medical School, Boston, MA 02115, USA
- Broad Institute of Harvard University and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
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4
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Vogt A, He Y, Lees-Miller SP. How to fix DNA breaks: new insights into the mechanism of non-homologous end joining. Biochem Soc Trans 2023; 51:1789-1800. [PMID: 37787023 PMCID: PMC10657183 DOI: 10.1042/bst20220741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 08/26/2023] [Accepted: 09/22/2023] [Indexed: 10/04/2023]
Abstract
Non-homologous end joining (NHEJ) is the major pathway for the repair of ionizing radiation-induced DNA double-strand breaks (DSBs) in human cells and is essential for the generation of mature T and B cells in the adaptive immune system via the process of V(D)J recombination. Here, we review how recently determined structures shed light on how NHEJ complexes function at DNA DSBs, emphasizing how multiple structures containing the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) may function in NHEJ. Together, these studies provide an explanation for how NHEJ proteins assemble to detect and protect DSB ends, then proceed, through DNA-PKcs-dependent autophosphorylation, to a ligation-competent complex.
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Affiliation(s)
- Alex Vogt
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, U.S.A
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, U.S.A
| | - Yuan He
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, U.S.A
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, U.S.A
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, U.S.A
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Northwestern University, Chicago, U.S.A
| | - Susan P. Lees-Miller
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre and Arnie Charbonneau Cancer Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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5
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Head PE, Kapoor-Vazirani P, Nagaraju GP, Zhang H, Rath S, Luong N, Haji-Seyed-Javadi R, Sesay F, Wang SY, Duong D, Daddacha W, Minten E, Song B, Danelia D, Liu X, Li S, Ortlund E, Seyfried N, Smalley D, Wang Y, Deng X, Dynan W, El-Rayes B, Davis A, Yu D. DNA-PK is activated by SIRT2 deacetylation to promote DNA double-strand break repair by non-homologous end joining. Nucleic Acids Res 2023; 51:7972-7987. [PMID: 37395399 PMCID: PMC10450170 DOI: 10.1093/nar/gkad549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 06/02/2023] [Accepted: 06/27/2023] [Indexed: 07/04/2023] Open
Abstract
DNA-dependent protein kinase (DNA-PK) plays a critical role in non-homologous end joining (NHEJ), the predominant pathway that repairs DNA double-strand breaks (DSB) in response to ionizing radiation (IR) to govern genome integrity. The interaction of the catalytic subunit of DNA-PK (DNA-PKcs) with the Ku70/Ku80 heterodimer on DSBs leads to DNA-PK activation; however, it is not known if upstream signaling events govern this activation. Here, we reveal a regulatory step governing DNA-PK activation by SIRT2 deacetylation, which facilitates DNA-PKcs localization to DSBs and interaction with Ku, thereby promoting DSB repair by NHEJ. SIRT2 deacetylase activity governs cellular resistance to DSB-inducing agents and promotes NHEJ. SIRT2 furthermore interacts with and deacetylates DNA-PKcs in response to IR. SIRT2 deacetylase activity facilitates DNA-PKcs interaction with Ku and localization to DSBs and promotes DNA-PK activation and phosphorylation of downstream NHEJ substrates. Moreover, targeting SIRT2 with AGK2, a SIRT2-specific inhibitor, augments the efficacy of IR in cancer cells and tumors. Our findings define a regulatory step for DNA-PK activation by SIRT2-mediated deacetylation, elucidating a critical upstream signaling event initiating the repair of DSBs by NHEJ. Furthermore, our data suggest that SIRT2 inhibition may be a promising rationale-driven therapeutic strategy for increasing the effectiveness of radiation therapy.
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Affiliation(s)
- PamelaSara E Head
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Priya Kapoor-Vazirani
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Ganji P Nagaraju
- School of Medicine, Division of Hematology and Medical Oncology, University of Alabama, Birmingham, AL 35233, USA
| | - Hui Zhang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Sandip K Rath
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Nho C Luong
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Ramona Haji-Seyed-Javadi
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Fatmata Sesay
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Shi-Ya Wang
- Department of Radiation Oncology, UT Southwestern Medical School, Dallas, TX 75390, USA
| | - Duc M Duong
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Waaqo Daddacha
- Department of Biochemistry and Molecular Biology, Augusta University, Augusta, GA 30912, USA
| | - Elizabeth V Minten
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Boying Song
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Diana Danelia
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Xu Liu
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Shuyi Li
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Eric A Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - David M Smalley
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Ya Wang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - Xingming Deng
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
| | - William S Dynan
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Bassel El-Rayes
- School of Medicine, Division of Hematology and Medical Oncology, University of Alabama, Birmingham, AL 35233, USA
| | - Anthony J Davis
- Department of Radiation Oncology, UT Southwestern Medical School, Dallas, TX 75390, USA
| | - David S Yu
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine,Atlanta, GA 30322, USA
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6
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Liu X, Burke RM, Lighthouse JK, Baker CD, Dirkx RA, Kang B, Chakraborty Y, Mickelsen DM, Twardowski J, Mello SS, Ashton JM, Small EM. p53 Regulates the Extent of Fibroblast Proliferation and Fibrosis in Left Ventricle Pressure Overload. Circ Res 2023; 133:271-287. [PMID: 37409456 PMCID: PMC10361635 DOI: 10.1161/circresaha.121.320324] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 06/22/2023] [Indexed: 07/07/2023]
Abstract
BACKGROUND Cardiomyopathy is characterized by the pathological accumulation of resident cardiac fibroblasts that deposit ECM (extracellular matrix) and generate a fibrotic scar. However, the mechanisms that control the timing and extent of cardiac fibroblast proliferation and ECM production are not known, hampering the development of antifibrotic strategies to prevent heart failure. METHODS We used the Tcf21 (transcription factor 21)MerCreMer mouse line for fibroblast-specific lineage tracing and p53 (tumor protein p53) gene deletion. We characterized cardiac physiology and used single-cell RNA-sequencing and in vitro studies to investigate the p53-dependent mechanisms regulating cardiac fibroblast cell cycle and fibrosis in left ventricular pressure overload induced by transaortic constriction. RESULTS Cardiac fibroblast proliferation occurs primarily between days 7 and 14 following transaortic constriction in mice, correlating with alterations in p53-dependent gene expression. p53 deletion in fibroblasts led to a striking accumulation of Tcf21-lineage cardiac fibroblasts within the normal proliferative window and precipitated a robust fibrotic response to left ventricular pressure overload. However, excessive interstitial and perivascular fibrosis does not develop until after cardiac fibroblasts exit the cell cycle. Single-cell RNA sequencing revealed p53 null fibroblasts unexpectedly express lower levels of genes encoding important ECM proteins while they exhibit an inappropriately proliferative phenotype. in vitro studies establish a role for p53 in suppressing the proliferative fibroblast phenotype, which facilitates the expression and secretion of ECM proteins. Importantly, Cdkn2a (cyclin-dependent kinase inhibitor 2a) expression and the p16Ink4a-retinoblastoma cell cycle control pathway is induced in p53 null cardiac fibroblasts, which may eventually contribute to cell cycle exit and fulminant scar formation. CONCLUSIONS This study reveals a mechanism regulating cardiac fibroblast accumulation and ECM secretion, orchestrated in part by p53-dependent cell cycle control that governs the timing and extent of fibrosis in left ventricular pressure overload.
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Affiliation(s)
- Xiaoyi Liu
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Ryan M. Burke
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Janet K. Lighthouse
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
- Wegmans School of Pharmacy, Department of Pharmaceutical Sciences, St. John Fisher College, Rochester, NY, USA
| | - Cameron D. Baker
- Genomics Research Center, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Ronald A. Dirkx
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Brian Kang
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Yashoswini Chakraborty
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Deanne M. Mickelsen
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Jennifer Twardowski
- Department of Biomedical Genetics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Stephano S. Mello
- Department of Biomedical Genetics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - John M. Ashton
- Genomics Research Center, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Eric M. Small
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
- Department of Medicine, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642
- Department of Biomedical Engineering, University of Rochester, Rochester, NY 14642
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7
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Lu H, Zhang Q, Laverty DJ, Puncheon AC, Augustine M, Williams G, Nagel Z, Chen BC, Davis A. ATM phosphorylates the FATC domain of DNA-PKcs at threonine 4102 to promote non-homologous end joining. Nucleic Acids Res 2023; 51:6770-6783. [PMID: 37309889 PMCID: PMC10359628 DOI: 10.1093/nar/gkad505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/26/2023] [Accepted: 05/31/2023] [Indexed: 06/14/2023] Open
Abstract
Ataxia-telangiectasia mutated (ATM) drives the DNA damage response via modulation of multiple signal transduction and DNA repair pathways. Previously, ATM activity was implicated in promoting the non-homologous end joining (NHEJ) pathway to repair a subset of DNA double-stranded breaks (DSBs), but how ATM performs this function is still unclear. In this study, we identified that ATM phosphorylates the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a core NHEJ factor, at its extreme C-terminus at threonine 4102 (T4102) in response to DSBs. Ablating phosphorylation at T4102 attenuates DNA-PKcs kinase activity and this destabilizes the interaction between DNA-PKcs and the Ku-DNA complex, resulting in decreased assembly and stabilization of the NHEJ machinery at DSBs. Phosphorylation at T4102 promotes NHEJ, radioresistance, and increases genomic stability following DSB induction. Collectively, these findings establish a key role for ATM in NHEJ-dependent repair of DSBs through positive regulation of DNA-PKcs.
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Affiliation(s)
- Huiming Lu
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX75390, USA
| | - Qin Zhang
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX75390, USA
| | - Daniel J Laverty
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA02115, USA
| | - Andrew C Puncheon
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX75390, USA
| | - Mathew M Augustine
- Division of Surgical Oncology, Department of Surgery, UT Southwestern Medical Center, Dallas, TX75390, USA
- Department of Surgery, North Texas VA Medical Center, Dallas, TX75216, USA
| | - Gareth J Williams
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Zachary D Nagel
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA02115, USA
| | - Benjamin P C Chen
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX75390, USA
| | - Anthony J Davis
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX75390, USA
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8
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Qin S, Kitty I, Hao Y, Zhao F, Kim W. Maintaining Genome Integrity: Protein Kinases and Phosphatases Orchestrate the Balancing Act of DNA Double-Strand Breaks Repair in Cancer. Int J Mol Sci 2023; 24:10212. [PMID: 37373360 DOI: 10.3390/ijms241210212] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
DNA double-strand breaks (DSBs) are the most lethal DNA damages which lead to severe genome instability. Phosphorylation is one of the most important protein post-translation modifications involved in DSBs repair regulation. Kinases and phosphatases play coordinating roles in DSB repair by phosphorylating and dephosphorylating various proteins. Recent research has shed light on the importance of maintaining a balance between kinase and phosphatase activities in DSB repair. The interplay between kinases and phosphatases plays an important role in regulating DNA-repair processes, and alterations in their activity can lead to genomic instability and disease. Therefore, study on the function of kinases and phosphatases in DSBs repair is essential for understanding their roles in cancer development and therapeutics. In this review, we summarize the current knowledge of kinases and phosphatases in DSBs repair regulation and highlight the advancements in the development of cancer therapies targeting kinases or phosphatases in DSBs repair pathways. In conclusion, understanding the balance of kinase and phosphatase activities in DSBs repair provides opportunities for the development of novel cancer therapeutics.
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Affiliation(s)
- Sisi Qin
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Ichiwa Kitty
- Department of Integrated Biomedical Science, Soonchunhyang Institute of Medi-Bio Science (SIMS), Soonchunhyang University, Cheonan 31151, Chungcheongnam-do, Republic of Korea
| | - Yalan Hao
- Analytical Instrumentation Center, Hunan University, Changsha 410082, China
| | - Fei Zhao
- College of Biology, Hunan University, Changsha 410082, China
| | - Wootae Kim
- Department of Integrated Biomedical Science, Soonchunhyang Institute of Medi-Bio Science (SIMS), Soonchunhyang University, Cheonan 31151, Chungcheongnam-do, Republic of Korea
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9
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Xie D, Huang Q, Zhou P. Drug Discovery Targeting Post-Translational Modifications in Response to DNA Damages Induced by Space Radiation. Int J Mol Sci 2023; 24:ijms24087656. [PMID: 37108815 PMCID: PMC10142602 DOI: 10.3390/ijms24087656] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/07/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
DNA damage in astronauts induced by cosmic radiation poses a major barrier to human space exploration. Cellular responses and repair of the most lethal DNA double-strand breaks (DSBs) are crucial for genomic integrity and cell survival. Post-translational modifications (PTMs), including phosphorylation, ubiquitylation, and SUMOylation, are among the regulatory factors modulating a delicate balance and choice between predominant DSB repair pathways, such as non-homologous end joining (NHEJ) and homologous recombination (HR). In this review, we focused on the engagement of proteins in the DNA damage response (DDR) modulated by phosphorylation and ubiquitylation, including ATM, DNA-PKcs, CtIP, MDM2, and ubiquitin ligases. The involvement and function of acetylation, methylation, PARylation, and their essential proteins were also investigated, providing a repository of candidate targets for DDR regulators. However, there is a lack of radioprotectors in spite of their consideration in the discovery of radiosensitizers. We proposed new perspectives for the research and development of future agents against space radiation by the systematic integration and utilization of evolutionary strategies, including multi-omics analyses, rational computing methods, drug repositioning, and combinations of drugs and targets, which may facilitate the use of radioprotectors in practical applications in human space exploration to combat fatal radiation hazards.
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Affiliation(s)
- Dafei Xie
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Taiping Road 27th, Haidian District, Beijing 100850, China
| | - Qi Huang
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Taiping Road 27th, Haidian District, Beijing 100850, China
- Department of Preventive Medicine, School of Public Health, University of South China, Changsheng West Road 28th, Zhengxiang District, Hengyang 421001, China
| | - Pingkun Zhou
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology (BKLRB), Beijing Institute of Radiation Medicine, Taiping Road 27th, Haidian District, Beijing 100850, China
- Department of Preventive Medicine, School of Public Health, University of South China, Changsheng West Road 28th, Zhengxiang District, Hengyang 421001, China
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10
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Chen W, Chiang J, Shang Z, Palchik G, Newman C, Zhang Y, Davis AJ, Lee H, Chen BPC. DNA-PKcs and ATM modulate mitochondrial ADP-ATP exchange as an oxidative stress checkpoint mechanism. EMBO J 2023; 42:e112094. [PMID: 36727301 PMCID: PMC10015379 DOI: 10.15252/embj.2022112094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 01/13/2023] [Accepted: 01/21/2023] [Indexed: 02/03/2023] Open
Abstract
DNA-PKcs is a key regulator of DNA double-strand break repair. Apart from its canonical role in the DNA damage response, DNA-PKcs is involved in the cellular response to oxidative stress (OS), but its exact role remains unclear. Here, we report that DNA-PKcs-deficient human cells display depolarized mitochondria membrane potential (MMP) and reoriented metabolism, supporting a role for DNA-PKcs in oxidative phosphorylation (OXPHOS). DNA-PKcs directly interacts with mitochondria proteins ANT2 and VDAC2, and formation of the DNA-PKcs/ANT2/VDAC2 (DAV) complex supports optimal exchange of ADP and ATP across mitochondrial membranes to energize the cell via OXPHOS and to maintain MMP. Moreover, we demonstrate that the DAV complex temporarily dissociates in response to oxidative stress to attenuate ADP-ATP exchange, a rate-limiting step for OXPHOS. Finally, we found that dissociation of the DAV complex is mediated by phosphorylation of DNA-PKcs at its Thr2609 cluster by ATM kinase. Based on these findings, we propose that the coordination between the DAV complex and ATM serves as a novel oxidative stress checkpoint to decrease ROS production from mitochondrial OXPHOS and to hasten cellular recovery from OS.
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Affiliation(s)
- Wei‐Min Chen
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
- Department of Life ScienceNational Taiwan UniversityTaipeiTaiwan
| | - Jui‐Chung Chiang
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
- Department of Life ScienceNational Taiwan UniversityTaipeiTaiwan
| | - Zengfu Shang
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
| | - Guillermo Palchik
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
| | - Ciara Newman
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
| | - Yuanyuan Zhang
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
| | - Anthony J Davis
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
| | - Hsinyu Lee
- Department of Life ScienceNational Taiwan UniversityTaipeiTaiwan
| | - Benjamin PC Chen
- Division of Molecular Radiation Biology, Department of Radiation OncologyUniversity of Texas Southwestern Medical Center at DallasDallasTXUSA
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11
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Murray HC, Miller K, Brzozowski JS, Kahl RGS, Smith ND, Humphrey SJ, Dun MD, Verrills NM. Synergistic Targeting of DNA-PK and KIT Signaling Pathways in KIT Mutant Acute Myeloid Leukemia. Mol Cell Proteomics 2023; 22:100503. [PMID: 36682716 PMCID: PMC9986649 DOI: 10.1016/j.mcpro.2023.100503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 12/19/2022] [Accepted: 01/13/2023] [Indexed: 01/21/2023] Open
Abstract
Acute myeloid leukemia (AML) is the most common and aggressive form of acute leukemia, with a 5-year survival rate of just 24%. Over a third of all AML patients harbor activating mutations in kinases, such as the receptor tyrosine kinases FLT3 (receptor-type tyrosine-protein kinase FLT3) and KIT (mast/stem cell growth factor receptor kit). FLT3 and KIT mutations are associated with poor clinical outcomes and lower remission rates in response to standard-of-care chemotherapy. We have recently identified that the core kinase of the non-homologous end joining DNA repair pathway, DNA-PK (DNA-dependent protein kinase), is activated downstream of FLT3; and targeting DNA-PK sensitized FLT3-mutant AML cells to standard-of-care therapies. Herein, we investigated DNA-PK as a possible therapeutic vulnerability in KIT mutant AML, using isogenic FDC-P1 mouse myeloid progenitor cell lines transduced with oncogenic mutant KIT (V560G and D816V) or vector control. Targeted quantitative phosphoproteomic profiling identified phosphorylation of DNA-PK in the T2599/T2605/S2608/S2610 cluster in KIT mutant cells, indicative of DNA-PK activation. Accordingly, proliferation assays revealed that KIT mutant FDC-P1 cells were more sensitive to the DNA-PK inhibitors M3814 or NU7441, compared with empty vector controls. DNA-PK inhibition combined with inhibition of KIT signaling using the kinase inhibitors dasatinib or ibrutinib, or the protein phosphatase 2A activators FTY720 or AAL(S), led to synergistic cell death. Global phosphoproteomic analysis of KIT-D816V cells revealed that dasatinib and M3814 single-agent treatments inhibited extracellular signal-regulated kinase and AKT (RAC-alpha serine/threonine-protein kinase)/MTOR (serine/threonine-protein kinase mTOR) activity, with greater inhibition of both pathways when used in combination. Combined dasatinib and M3814 treatment also synergistically inhibited phosphorylation of the transcriptional regulators MYC and MYB. This study provides insight into the oncogenic pathways regulated by DNA-PK beyond its canonical role in DNA repair and demonstrates that DNA-PK is a promising therapeutic target for KIT mutant cancers.
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Affiliation(s)
- Heather C Murray
- School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, University of Newcastle, and Hunter Cancer Research Alliance and Precision Medicine Program, Hunter Medical Research Institute, Callaghan, New South Wales, Australia
| | - Kasey Miller
- School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, University of Newcastle, and Hunter Cancer Research Alliance and Precision Medicine Program, Hunter Medical Research Institute, Callaghan, New South Wales, Australia
| | - Joshua S Brzozowski
- School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, University of Newcastle, and Hunter Cancer Research Alliance and Precision Medicine Program, Hunter Medical Research Institute, Callaghan, New South Wales, Australia
| | - Richard G S Kahl
- School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, University of Newcastle, and Hunter Cancer Research Alliance and Precision Medicine Program, Hunter Medical Research Institute, Callaghan, New South Wales, Australia
| | - Nathan D Smith
- Analytical and Biomolecular Research Facility, Advanced Mass Spectrometry Unit, University of Newcastle, Callaghan, New South Wales, Australia
| | - Sean J Humphrey
- School of Life and Environmental Sciences, and The Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia
| | - Matthew D Dun
- School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, University of Newcastle, and Hunter Cancer Research Alliance and Precision Medicine Program, Hunter Medical Research Institute, Callaghan, New South Wales, Australia
| | - Nicole M Verrills
- School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, University of Newcastle, and Hunter Cancer Research Alliance and Precision Medicine Program, Hunter Medical Research Institute, Callaghan, New South Wales, Australia.
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12
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Mendoza-Munoz PL, Gavande NS, VanderVere-Carozza PS, Pawelczak K, Dynlacht J, Garrett J, Turchi J. Ku-DNA binding inhibitors modulate the DNA damage response in response to DNA double-strand breaks. NAR Cancer 2023; 5:zcad003. [PMID: 36755959 PMCID: PMC9900423 DOI: 10.1093/narcan/zcad003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/09/2022] [Accepted: 01/30/2023] [Indexed: 02/09/2023] Open
Abstract
The DNA-dependent protein kinase (DNA-PK) plays a critical role in the DNA damage response (DDR) and non-homologous end joining (NHEJ) double-strand break (DSB) repair pathways. Consequently, DNA-PK is a validated therapeutic target for cancer treatment in certain DNA repair-deficient cancers and in combination with ionizing radiation (IR). We have previously reported the discovery and development of a novel class of DNA-PK inhibitors with a unique mechanism of action, blocking the Ku 70/80 heterodimer interaction with DNA. These Ku-DNA binding inhibitors (Ku-DBi's) display nanomolar activity in vitro, inhibit cellular DNA-PK, NHEJ-catalyzed DSB repair and sensitize non-small cell lung cancer (NSCLC) cells to DSB-inducing agents. In this study, we demonstrate that chemical inhibition of the Ku-DNA interaction potentiates the cellular effects of bleomycin and IR via p53 phosphorylation through the activation of the ATM pathway. This response is concomitant with a reduction of DNA-PK catalytic subunit (DNA-PKcs) autophosphorylation at S2056 and a time-dependent increase in H2AX phosphorylation at S139. These results are consistent with Ku-DBi's abrogating DNA-PKcs autophosphorylation to impact DSB repair and DDR signaling through a novel mechanism of action, and thus represent a promising anticancer therapeutic strategy in combination with DNA DSB-inducing agents.
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Affiliation(s)
- Pamela L Mendoza-Munoz
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Navnath S Gavande
- Department of Pharmaceutical Sciences, Wayne State University College of Pharmacy and Health Sciences, Detroit, MI 48201-2417, USA
- Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute, Wayne State University, Detroit, MI 48201-2417, USA
| | | | | | - Joseph R Dynlacht
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Joy E Garrett
- Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - John J Turchi
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- NERx Biosciences. Indianapolis, IN 46202, USA
- Department of Biochemistry and Molecular Biology, Indiana University, School of Medicine, Indianapolis, IN 46202, USA
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13
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Lu H, Zhang Q, Laverty DJ, Puncheon AC, Williams GJ, Nagel ZD, Chen BP, Davis AJ. ATM phosphorylates the FATC domain of DNA-PK cs at threonine 4102 to promote non-homologous end joining. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.02.526879. [PMID: 36778257 PMCID: PMC9915669 DOI: 10.1101/2023.02.02.526879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Ataxia-telangiectasia mutated (ATM) drives the DNA damage response via modulation of multiple signal transduction and DNA repair pathways. Previously, ATM activity was implicated in promoting the non-homologous end joining (NHEJ) pathway to repair a subset of DNA double strand breaks (DSBs), but how ATM performs this function is still unclear. In this study, we identified that ATM phosphorylates the DNA-dependent protein kinase catalytic subunit (DNA-PK cs ), a core NHEJ factor, at its extreme C-terminus at threonine 4102 (T4102) in response to DSBs. Phosphorylation at T4102 stabilizes the interaction between DNA-PK cs and the Ku-DNA complex and promotes assembly and stabilization of the NHEJ machinery at DSBs. Ablating phosphorylation at this site results in decreased NHEJ, radiosensitivity, and increased radiation-induced genomic instability. Collectively, these findings establish a key role for ATM in NHEJ-dependent repair of DSBs through positive regulation of DNA-PK cs .
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14
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Wang P, Wang HY, Gao XJ, Zhu HX, Zhang XP, Liu F, Wang W. Encoding and Decoding of p53 Dynamics in Cellular Response to Stresses. Cells 2023; 12:cells12030490. [PMID: 36766831 PMCID: PMC9914463 DOI: 10.3390/cells12030490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/20/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023] Open
Abstract
In the cellular response to stresses, the tumor suppressor p53 is activated to maintain genomic integrity and fidelity. As a transcription factor, p53 exhibits rich dynamics to allow for discrimination of the type and intensity of stresses and to direct the selective activation of target genes involved in different processes including cell cycle arrest and apoptosis. In this review, we focused on how stresses are encoded into p53 dynamics and how the dynamics are decoded into cellular outcomes. Theoretical modeling may provide a global view of signaling in the p53 network by coupling the encoding and decoding processes. We discussed the significance of modeling in revealing the mechanisms of the transition between p53 dynamic modes. Moreover, we shed light on the crosstalk between the p53 network and other signaling networks. This review may advance the understanding of operating principles of the p53 signaling network comprehensively and provide insights into p53 dynamics-based cancer therapy.
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Affiliation(s)
- Ping Wang
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China
- Key Laboratory of High Performance Scientific Computation, School of Science, Xihua University, Chengdu 610039, China
| | - Hang-Yu Wang
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China
| | - Xing-Jie Gao
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China
| | - Hua-Xia Zhu
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China
| | - Xiao-Peng Zhang
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China
- Institute of Brain Sciences, Nanjing University, Nanjing 210093, China
- Correspondence: (X.-P.Z.); (W.W.)
| | - Feng Liu
- Institute of Brain Sciences, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructure, Nanjing University, Nanjing 210093, China
- Department of Physics, Nanjing University, Nanjing 210093, China
| | - Wei Wang
- Institute of Brain Sciences, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructure, Nanjing University, Nanjing 210093, China
- Department of Physics, Nanjing University, Nanjing 210093, China
- Correspondence: (X.-P.Z.); (W.W.)
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15
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Novotny JP, Mariño-Enríquez A, Fletcher JA. Targeting DNA-PK. Cancer Treat Res 2023; 186:299-312. [PMID: 37978142 DOI: 10.1007/978-3-031-30065-3_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
This chapter explores the multifaceted roles of DNA-PK with particular focus on its functions in non-homologous end-joining (NHEJ) DNA repair. DNA-PK is the primary orchestrator of NHEJ but also regulates other biologic processes. The growing understanding of varied DNA-PK biologic roles highlights new avenues for cancer treatment. However, these multiple roles also imply challenges, particularly in combination therapies, with perhaps a higher risk of clinical toxicities than was previously envisioned. These considerations underscore the need for compelling and innovative strategies to accomplish effective clinical translation.
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16
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Nickoloff JA. Targeting Replication Stress Response Pathways to Enhance Genotoxic Chemo- and Radiotherapy. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27154736. [PMID: 35897913 PMCID: PMC9330692 DOI: 10.3390/molecules27154736] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 12/12/2022]
Abstract
Proliferating cells regularly experience replication stress caused by spontaneous DNA damage that results from endogenous reactive oxygen species (ROS), DNA sequences that can assume secondary and tertiary structures, and collisions between opposing transcription and replication machineries. Cancer cells face additional replication stress, including oncogenic stress that results from the dysregulation of fork progression and origin firing, and from DNA damage induced by radiotherapy and most cancer chemotherapeutic agents. Cells respond to such stress by activating a complex network of sensor, signaling and effector pathways that protect genome integrity. These responses include slowing or stopping active replication forks, protecting stalled replication forks from collapse, preventing late origin replication firing, stimulating DNA repair pathways that promote the repair and restart of stalled or collapsed replication forks, and activating dormant origins to rescue adjacent stressed forks. Currently, most cancer patients are treated with genotoxic chemotherapeutics and/or ionizing radiation, and cancer cells can gain resistance to the resulting replication stress by activating pro-survival replication stress pathways. Thus, there has been substantial effort to develop small molecule inhibitors of key replication stress proteins to enhance tumor cell killing by these agents. Replication stress targets include ATR, the master kinase that regulates both normal replication and replication stress responses; the downstream signaling kinase Chk1; nucleases that process stressed replication forks (MUS81, EEPD1, Metnase); the homologous recombination catalyst RAD51; and other factors including ATM, DNA-PKcs, and PARP1. This review provides an overview of replication stress response pathways and discusses recent pre-clinical studies and clinical trials aimed at improving cancer therapy by targeting replication stress response factors.
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Affiliation(s)
- Jac A Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA
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17
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ATR Contributes More Than ATM in Intra-S-Phase Checkpoint Activation after IR, and DNA-PKcs Facilitates Recovery: Evidence for Modular Integration of ATM/ATR/DNA-PKcs Functions. Int J Mol Sci 2022; 23:ijms23147506. [PMID: 35886852 PMCID: PMC9316047 DOI: 10.3390/ijms23147506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/24/2022] [Accepted: 07/04/2022] [Indexed: 11/25/2022] Open
Abstract
The intra-S-phase checkpoint was among the first reported cell cycle checkpoints in mammalian cells. It transiently slows down the rate of DNA replication after DNA damage to facilitate repair and thus prevents genomic instability. The ionizing radiation (IR)-induced intra-S-phase checkpoint in mammalian cells is thought to be mainly dependent upon the kinase activity of ATM. Defects in the intra-S-phase checkpoint result in radio-resistant DNA synthesis (RDS), which promotes genomic instability. ATM belongs to the PI3K kinase family along with ATR and DNA-PKcs. ATR has been shown to be the key kinase for intra-S-phase checkpoint signaling in yeast and has also been implicated in this checkpoint in higher eukaryotes. Recently, contributions of DNA-PKcs to IR-induced G2-checkpoint could also be established. Whether and how ATR and DNA-PKcs are involved in the IR-induced intra-S-phase checkpoint in mammalian cells is incompletely characterized. Here, we investigated the contributions of ATM, ATR, and DNA-PKcs to intra-S-phase checkpoint activation after exposure to IR of human and hamster cells. The results suggest that the activities of both ATM and ATR are essential for efficient intra-S-phase checkpoint activation. Indeed, in a wild-type genetic background, ATR inhibition generates stronger checkpoint defects than ATM inhibition. Similar to G2 checkpoint, DNA-PKcs contributes to the recovery from the intra-S-phase checkpoint. DNA-PKcs–deficient cells show persistent, mainly ATR-dependent intra-S-phase checkpoints. A correlation between the degree of DSB end resection and the strength of the intra-S-phase checkpoint is observed, which again compares well to the G2 checkpoint response. We conclude that the organization of the intra-S-phase checkpoint has a similar mechanistic organization to that of the G2 checkpoint in cells irradiated in the G2 phase.
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18
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Bergstrand S, O'Brien EM, Coucoravas C, Hrossova D, Peirasmaki D, Schmidli S, Dhanjal S, Pederiva C, Siggens L, Mortusewicz O, O'Rourke JJ, Farnebo M. Small Cajal body-associated RNA 2 (scaRNA2) regulates DNA repair pathway choice by inhibiting DNA-PK. Nat Commun 2022; 13:1015. [PMID: 35197472 PMCID: PMC8866460 DOI: 10.1038/s41467-022-28646-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 01/25/2022] [Indexed: 12/20/2022] Open
Abstract
Evidence that long non-coding RNAs (lncRNAs) participate in DNA repair is accumulating, however, whether they can control DNA repair pathway choice is unknown. Here we show that the small Cajal body-specific RNA 2 (scaRNA2) can promote HR by inhibiting DNA-dependent protein kinase (DNA-PK) and, thereby, NHEJ. By binding to the catalytic subunit of DNA-PK (DNA-PKcs), scaRNA2 weakens its interaction with the Ku70/80 subunits, as well as with the LINP1 lncRNA, thereby preventing catalytic activation of the enzyme. Inhibition of DNA-PK by scaRNA2 stimulates DNA end resection by the MRN/CtIP complex, activation of ATM at DNA lesions and subsequent repair by HR. ScaRNA2 is regulated in turn by WRAP53β, which binds this RNA, sequestering it away from DNA-PKcs and allowing NHEJ to proceed. These findings reveal that RNA-dependent control of DNA-PK catalytic activity is involved in regulating whether the cell utilizes NHEJ or HR. Proper repair of DNA double-strand breaks is essential for genomic stability. Here, the authors report that a long non-coding RNA, scaRNA2, inhibits DNA-PK and thereby regulates the choice between error-prone NHEJ and error-free HR DNA repair.
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Affiliation(s)
- Sofie Bergstrand
- Department of Biosciences and Nutrition, Neo, Karolinska Institutet, Stockholm, Sweden
| | - Eleanor M O'Brien
- Department of Cell and Molecular biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Christos Coucoravas
- Department of Cell and Molecular biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Dominika Hrossova
- Department of Cell and Molecular biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Dimitra Peirasmaki
- Department of Cell and Molecular biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Sandro Schmidli
- Department of Cell and Molecular biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Soniya Dhanjal
- Department of Cell and Molecular biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Chiara Pederiva
- Department of Cell and Molecular biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Lee Siggens
- Department of Biosciences and Nutrition, Neo, Karolinska Institutet, Stockholm, Sweden
| | - Oliver Mortusewicz
- Department of Oncology and Pathology, SciLife, Karolinska Institutet, Stockholm, Sweden
| | - Julienne J O'Rourke
- Department of Cell and Molecular biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden
| | - Marianne Farnebo
- Department of Biosciences and Nutrition, Neo, Karolinska Institutet, Stockholm, Sweden. .,Department of Cell and Molecular biology, Biomedicum, Karolinska Institutet, Stockholm, Sweden.
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19
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Dylgjeri E, Knudsen KE. DNA-PKcs: A Targetable Protumorigenic Protein Kinase. Cancer Res 2022; 82:523-533. [PMID: 34893509 PMCID: PMC9306356 DOI: 10.1158/0008-5472.can-21-1756] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/17/2021] [Accepted: 11/10/2021] [Indexed: 01/07/2023]
Abstract
DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a pleiotropic protein kinase that plays critical roles in cellular processes fundamental to cancer. DNA-PKcs expression and activity are frequently deregulated in multiple hematologic and solid tumors and have been tightly linked to poor outcome. Given the potentially influential role of DNA-PKcs in cancer development and progression, therapeutic targeting of this kinase is being tested in preclinical and clinical settings. This review summarizes the latest advances in the field, providing a comprehensive discussion of DNA-PKcs functions in cancer and an update on the clinical assessment of DNA-PK inhibitors in cancer therapy.
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Affiliation(s)
- Emanuela Dylgjeri
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.,Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Karen E. Knudsen
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.,Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania.,Department of Medical Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania.,Department of Urology, Thomas Jefferson University, Philadelphia, Pennsylvania.,Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania.,Corresponding Author: Karen E. Knudsen, Thomas Jefferson University, 233 South 10th Street, BLSB 1050, Philadelphia, PA 19107. Phone: 215-503-5692; E-mail:
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20
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HIF-1 Interacts with TRIM28 and DNA-PK to release paused RNA polymerase II and activate target gene transcription in response to hypoxia. Nat Commun 2022; 13:316. [PMID: 35031618 PMCID: PMC8760265 DOI: 10.1038/s41467-021-27944-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 12/15/2021] [Indexed: 12/11/2022] Open
Abstract
Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that acts as a regulator of oxygen (O2) homeostasis in metazoan species by binding to hypoxia response elements (HREs) and activating the transcription of hundreds of genes in response to reduced O2 availability. RNA polymerase II (Pol II) initiates transcription of many HIF target genes under non-hypoxic conditions but pauses after approximately 30–60 nucleotides and requires HIF-1 binding for release. Here we report that in hypoxic breast cancer cells, HIF-1 recruits TRIM28 and DNA-dependent protein kinase (DNA-PK) to HREs to release paused Pol II. We show that HIF-1α and TRIM28 assemble the catalytically-active DNA-PK heterotrimer, which phosphorylates TRIM28 at serine-824, enabling recruitment of CDK9, which phosphorylates serine-2 of the Pol II large subunit C-terminal domain as well as the negative elongation factor to release paused Pol II, thereby stimulating productive transcriptional elongation. Our studies reveal a molecular mechanism by which HIF-1 stimulates gene transcription and reveal that the anticancer effects of drugs targeting DNA-PK in breast cancer may be due in part to their inhibition of HIF-dependent transcription. Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that modulates target gene expression in response to changes in oxygen availability. Here the authors show that HIF-1 forms a complex with TRIM28 and DNA-dependent protein kinase (DNA-PK) that phosphorylates TRIM28. This leads to CDK9 recruitment, which stimulates RNA polymerase II (RNAPII) pause release and transcriptional elongation.
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21
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Ueno S, Sudo T, Hirasawa A. ATM: Functions of ATM Kinase and Its Relevance to Hereditary Tumors. Int J Mol Sci 2022; 23:523. [PMID: 35008949 PMCID: PMC8745051 DOI: 10.3390/ijms23010523] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/22/2021] [Accepted: 12/28/2021] [Indexed: 02/04/2023] Open
Abstract
Ataxia-telangiectasia mutated (ATM) functions as a key initiator and coordinator of DNA damage and cellular stress responses. ATM signaling pathways contain many downstream targets that regulate multiple important cellular processes, including DNA damage repair, apoptosis, cell cycle arrest, oxidative sensing, and proliferation. Over the past few decades, associations between germline ATM pathogenic variants and cancer risk have been reported, particularly for breast and pancreatic cancers. In addition, given that ATM plays a critical role in repairing double-strand breaks, inhibiting other DNA repair pathways could be a synthetic lethal approach. Based on this rationale, several DNA damage response inhibitors are currently being tested in ATM-deficient cancers. In this review, we discuss the current knowledge related to the structure of the ATM gene, function of ATM kinase, clinical significance of ATM germline pathogenic variants in patients with hereditary cancers, and ongoing efforts to target ATM for the benefit of cancer patients.
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Affiliation(s)
- Sayaka Ueno
- Section of Translational Research, Hyogo Cancer Center, 13-70 Kita-Oji-cho, Akashi-shi 673-8558, Japan;
- Department of Clinical Genomic Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan;
| | - Tamotsu Sudo
- Section of Translational Research, Hyogo Cancer Center, 13-70 Kita-Oji-cho, Akashi-shi 673-8558, Japan;
| | - Akira Hirasawa
- Department of Clinical Genomic Medicine, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan;
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22
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Zhang H, Ma RR, Zhang G, Dong Y, Duan M, Sun Y, Tian Y, Gao JW, Chen X, Liu HT, Gao P. Long noncoding RNA lnc-LEMGC combines with DNA-PKcs to suppress gastric cancer metastasis. Cancer Lett 2022; 524:82-90. [PMID: 34626692 DOI: 10.1016/j.canlet.2021.09.042] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 11/24/2022]
Abstract
Long non-coding RNAs (lncRNAs) play important roles in cancer development and progression; however, their contributions to gastric cancer metastasis remain largely unknown. By lncRNA microarray screening, our study showed that 453 lncRNAs are dysregulated in gastric cancer tissues with or without lymph node metastasis, of which lnc-LEMGC ranks as one of the most significantly downregulated lncRNAs. Lnc-LEMGC inhibited cell migration and invasion both in vitro and in vivo, by combining with protein DNA-PKcs. Importantly, nucleotides 1300-1800 of lnc-LEMGC prevented DNA-PKcs phosphorylation of serine 2056 and partially abrogated the effects of downstream effectors, ErbB1, SRC and protein tyrosine kinase 2 (FAK), in the epidermal growth factor receptor (EGFR) pathway. The results of this study extend our knowledge of lncRNA's molecular mechanisms, in which lnc-LEMGC functions by directly suppressing the phosphorylation of its combined protein DNA-PKcs and inactivating the DNA-PKcs downstream EGFR signaling.
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Affiliation(s)
- Hui Zhang
- Department of Pathology, Qilu Hospital, Shandong University, Jinan, PR China; Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, PR China
| | - Ran-Ran Ma
- Department of Pathology, Qilu Hospital, Shandong University, Jinan, PR China; Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, PR China
| | - GuoHao Zhang
- Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, PR China
| | - Yi Dong
- Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, PR China
| | - Miao Duan
- Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, PR China
| | - YiYuan Sun
- Department of Pathology, Qilu Hospital, Shandong University, Jinan, PR China
| | - YaRu Tian
- Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, PR China
| | - Ji-Wei Gao
- Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, PR China
| | - Xu Chen
- Department of Pathology, Qilu Hospital, Shandong University, Jinan, PR China; Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, PR China
| | - Hai-Ting Liu
- Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, PR China
| | - Peng Gao
- Department of Pathology, Qilu Hospital, Shandong University, Jinan, PR China; Key Laboratory for Experimental Teratology of the Ministry of Education and Department of Pathology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, PR China.
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23
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Shift in G1-Checkpoint from ATM-Alone to a Cooperative ATM Plus ATR Regulation with Increasing Dose of Radiation. Cells 2021; 11:cells11010063. [PMID: 35011623 PMCID: PMC8750242 DOI: 10.3390/cells11010063] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 12/13/2022] Open
Abstract
The current view of the involvement of PI3-kinases in checkpoint responses after DNA damage is that ATM is the key regulator of G1-, S- or G2-phase checkpoints, that ATR is only partly involved in the regulation of S- and G2-phase checkpoints and that DNA-PKcs is not involved in checkpoint regulation. However, further analysis of the contributions of these kinases to checkpoint responses in cells exposed to ionizing radiation (IR) recently uncovered striking integrations and interplays among ATM, ATR and DNA-PKcs that adapt not only to the phase of the cell cycle in which cells are irradiated, but also to the load of DNA double-strand breaks (DSBs), presumably to optimize their processing. Specifically, we found that low IR doses in G2-phase cells activate a G2-checkpoint that is regulated by epistatically coupled ATM and ATR. Thus, inhibition of either kinase suppresses almost fully its activation. At high IR doses, the epistatic ATM/ATR coupling relaxes, yielding to a cooperative regulation. Thus, single-kinase inhibition suppresses partly, and only combined inhibition suppresses fully G2-checkpoint activation. Interestingly, DNA-PKcs integrates with ATM/ATR in G2-checkpoint control, but functions in its recovery in a dose-independent manner. Strikingly, irradiation during S-phase activates, independently of dose, an exclusively ATR-dependent G2 checkpoint. Here, ATM couples with DNA-PKcs to regulate checkpoint recovery. In the present work, we extend these studies and investigate organization and functions of these PI3-kinases in the activation of the G1 checkpoint in cells irradiated either in the G0 or G1 phase. We report that ATM is the sole regulator of the G1 checkpoint after exposure to low IR doses. At high IR doses, ATM remains dominant, but contributions from ATR also become detectable and are associated with limited ATM/ATR-dependent end resection at DSBs. Under these conditions, only combined ATM + ATR inhibition fully abrogates checkpoint and resection. Contributions of DNA-PKcs and CHK2 to the regulation of the G1 checkpoint are not obvious in these experiments and may be masked by the endpoint employed for checkpoint analysis and perturbations in normal progression through the cell cycle of cells exposed to DNA-PKcs inhibitors. The results broaden our understanding of organization throughout the cell cycle and adaptation with increasing IR dose of the ATM/ATR/DNA-PKcs module to regulate checkpoint responses. They emphasize notable similarities and distinct differences between G1-, G2- and S-phase checkpoint regulation that may guide DSB processing decisions.
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24
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Cellular functions of the protein kinase ATM and their relevance to human disease. Nat Rev Mol Cell Biol 2021; 22:796-814. [PMID: 34429537 DOI: 10.1038/s41580-021-00394-2] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2021] [Indexed: 02/07/2023]
Abstract
The protein kinase ataxia telangiectasia mutated (ATM) is a master regulator of double-strand DNA break (DSB) signalling and stress responses. For three decades, ATM has been investigated extensively to elucidate its roles in the DNA damage response (DDR) and in the pathogenesis of ataxia telangiectasia (A-T), a human neurodegenerative disease caused by loss of ATM. Although hundreds of proteins have been identified as ATM phosphorylation targets and many important roles for this kinase have been identified, it is still unclear how ATM deficiency leads to the early-onset cerebellar degeneration that is common in all individuals with A-T. Recent studies suggest the existence of links between ATM deficiency and other cerebellum-specific neurological disorders, as well as the existence of broader similarities with more common neurodegenerative disorders. In this Review, we discuss recent structural insights into ATM regulation, and possible aetiologies of A-T phenotypes, including reactive oxygen species, mitochondrial dysfunction, alterations in transcription, R-loop metabolism and alternative splicing, defects in cellular proteostasis and metabolism, and potential pathogenic roles for hyper-poly(ADP-ribosyl)ation.
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25
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Matsumoto Y, Asa ADDC, Modak C, Shimada M. DNA-Dependent Protein Kinase Catalytic Subunit: The Sensor for DNA Double-Strand Breaks Structurally and Functionally Related to Ataxia Telangiectasia Mutated. Genes (Basel) 2021; 12:genes12081143. [PMID: 34440313 PMCID: PMC8394720 DOI: 10.3390/genes12081143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 07/19/2021] [Accepted: 07/22/2021] [Indexed: 11/16/2022] Open
Abstract
The DNA-dependent protein kinase (DNA-PK) is composed of a DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and Ku70/Ku80 heterodimer. DNA-PK is thought to act as the “sensor” for DNA double-stranded breaks (DSB), which are considered the most deleterious type of DNA damage. In particular, DNA-PKcs and Ku are shown to be essential for DSB repair through nonhomologous end joining (NHEJ). The phenotypes of animals and human individuals with defective DNA-PKcs or Ku functions indicate their essential roles in these developments, especially in neuronal and immune systems. DNA-PKcs are structurally related to Ataxia–telangiectasia mutated (ATM), which is also implicated in the cellular responses to DSBs. DNA-PKcs and ATM constitute the phosphatidylinositol 3-kinase-like kinases (PIKKs) family with several other molecules. Here, we review the accumulated knowledge on the functions of DNA-PKcs, mainly based on the phenotypes of DNA-PKcs-deficient cells in animals and human individuals, and also discuss its relationship with ATM in the maintenance of genomic stability.
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26
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Paull TT. Reconsidering pathway choice: a sequential model of mammalian DNA double-strand break pathway decisions. Curr Opin Genet Dev 2021; 71:55-62. [PMID: 34293662 DOI: 10.1016/j.gde.2021.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/14/2021] [Accepted: 06/29/2021] [Indexed: 12/27/2022]
Abstract
DNA double-strand breaks can be repaired through ligation-based pathways (non-homologous end-joining) or replication-based pathways (homologous recombination) in eukaryotic cells. The decisions that govern these outcomes are widely viewed as a competition between factors that recognize DNA ends and physically promote association of factors specific to each pathway, commonly known as 'pathway choice'. Here I review recent results in the literature and propose that this decision is better described as a sequential set of binding and end processing events, with non-homologous end joining as the first decision point. Physical association and co-localization of end resection factors with non-homologous end-joining factors suggests that ends are transferred between these complexes, thus the ultimate outcome is not the result of a competition but is more akin to a relay race that is determined by the efficiency of the initial end-joining event and the availability of activated DNA end-processing enzymes.
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Affiliation(s)
- Tanya T Paull
- The University of Texas at Austin, Department of Molecular Biosciences, Austin, TX, 78712, United States.
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27
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Burgess JT, Cheong CM, Suraweera A, Sobanski T, Beard S, Dave K, Rose M, Boucher D, Croft LV, Adams MN, O'Byrne K, Richard DJ, Bolderson E. Barrier-to-autointegration-factor (Banf1) modulates DNA double-strand break repair pathway choice via regulation of DNA-dependent kinase (DNA-PK) activity. Nucleic Acids Res 2021; 49:3294-3307. [PMID: 33660778 PMCID: PMC8034644 DOI: 10.1093/nar/gkab110] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/04/2021] [Accepted: 02/23/2021] [Indexed: 01/07/2023] Open
Abstract
DNA repair pathways are essential to maintain the integrity of the genome and prevent cell death and tumourigenesis. Here, we show that the Barrier-to-Autointegration Factor (Banf1) protein has a role in the repair of DNA double-strand breaks. Banf1 is characterized as a nuclear envelope protein and mutations in Banf1 are associated with the severe premature aging syndrome, Néstor–Guillermo Progeria Syndrome. We have previously shown that Banf1 directly regulates the activity of PARP1 in the repair of oxidative DNA lesions. Here, we show that Banf1 also has a role in modulating DNA double-strand break repair through regulation of the DNA-dependent Protein Kinase catalytic subunit, DNA-PKcs. Specifically, we demonstrate that Banf1 relocalizes from the nuclear envelope to sites of DNA double-strand breaks. We also show that Banf1 can bind to and directly inhibit the activity of DNA-PKcs. Supporting this, cellular depletion of Banf1 leads to an increase in non-homologous end-joining and a decrease in homologous recombination, which our data suggest is likely due to unrestrained DNA-PKcs activity. Overall, this study identifies how Banf1 regulates double-strand break repair pathway choice by modulating DNA-PKcs activity to control genome stability within the cell.
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Affiliation(s)
- Joshua T Burgess
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Chee Man Cheong
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Amila Suraweera
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Thais Sobanski
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Sam Beard
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Keyur Dave
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Maddison Rose
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Didier Boucher
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Laura V Croft
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Mark N Adams
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Kenneth O'Byrne
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia.,Princess Alexandra Hospital, Ipswich Road, Woolloongabba, Brisbane, Queensland 4102, Australia
| | - Derek J Richard
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
| | - Emma Bolderson
- Queensland University of Technology (QUT), Cancer & Ageing Research Program, Centre for Genomics and Personalised Health at the Translational Research Institute (TRI), Brisbane, Australia
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28
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Jiang Y, Dong Y, Luo Y, Jiang S, Meng FL, Tan M, Li J, Zang Y. AMPK-mediated phosphorylation on 53BP1 promotes c-NHEJ. Cell Rep 2021; 34:108713. [PMID: 33596428 DOI: 10.1016/j.celrep.2021.108713] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 11/12/2020] [Accepted: 01/12/2021] [Indexed: 12/25/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is an energy sensor that plays roles in multiple biological processes beyond metabolism. Several studies have suggested that AMPK is involved in the DNA damage response (DDR), but the mechanisms remain unclear. Herein, we demonstrate that AMPK promotes classic non-homologous end joining (c-NHEJ) in double-strand break (DSB) repair through recruiting a key chromatin-based mediator named p53-binding protein 1 (53BP1), which facilitates the end joining of distal DNA ends during DDR. We find that the interaction of AMPK and 53BP1 spatially occurs under DSB stress. In the context of DSBs, AMPK directly phosphorylates 53BP1 at Ser1317 and promotes 53BP1 recruitment during DDR for an efficient c-NHEJ, thus maintaining genomic stability and diversity of the immune repertoire. Taken together, our study demonstrates that AMPK is a regulator of 53BP1 and controls c-NHEJ choice by phospho-regulation.
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Affiliation(s)
- Yuejing Jiang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Ying Dong
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Yifeng Luo
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China; State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Shangwen Jiang
- Chemical Proteomics Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Fei-Long Meng
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China; State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Minjia Tan
- University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China; Chemical Proteomics Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Jia Li
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China; Open Studio for Druggability Research of Marine Natural Products, Pilot National Laboratory for Marine Science and Technology (Qingdao), 1 Wenhai Road, Aoshanwei, Jimo, Qingdao 266237, China; School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China.
| | - Yi Zang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing 100049, China; School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China.
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29
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Zell J, Rota Sperti F, Britton S, Monchaud D. DNA folds threaten genetic stability and can be leveraged for chemotherapy. RSC Chem Biol 2021; 2:47-76. [PMID: 35340894 PMCID: PMC8885165 DOI: 10.1039/d0cb00151a] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 09/20/2020] [Indexed: 12/22/2022] Open
Abstract
Damaging DNA is a current and efficient strategy to fight against cancer cell proliferation. Numerous mechanisms exist to counteract DNA damage, collectively referred to as the DNA damage response (DDR) and which are commonly dysregulated in cancer cells. Precise knowledge of these mechanisms is necessary to optimise chemotherapeutic DNA targeting. New research on DDR has uncovered a series of promising therapeutic targets, proteins and nucleic acids, with application notably via an approach referred to as combination therapy or combinatorial synthetic lethality. In this review, we summarise the cornerstone discoveries which gave way to the DNA being considered as an anticancer target, and the manipulation of DDR pathways as a valuable anticancer strategy. We describe in detail the DDR signalling and repair pathways activated in response to DNA damage. We then summarise the current understanding of non-B DNA folds, such as G-quadruplexes and DNA junctions, when they are formed and why they can offer a more specific therapeutic target compared to that of canonical B-DNA. Finally, we merge these subjects to depict the new and highly promising chemotherapeutic strategy which combines enhanced-specificity DNA damaging and DDR targeting agents. This review thus highlights how chemical biology has given rise to significant scientific advances thanks to resolutely multidisciplinary research efforts combining molecular and cell biology, chemistry and biophysics. We aim to provide the non-specialist reader a gateway into this exciting field and the specialist reader with a new perspective on the latest results achieved and strategies devised.
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Affiliation(s)
- Joanna Zell
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon France
| | - Francesco Rota Sperti
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon France
| | - Sébastien Britton
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS Toulouse France
- Équipe Labellisée la Ligue Contre le Cancer 2018 Toulouse France
| | - David Monchaud
- Institut de Chimie Moléculaire de l'Université de Bourgogne, ICMUB CNRS UMR 6302, UBFC Dijon France
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30
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Panigrahi R, Glover JNM. Structural insights into DNA double-strand break signaling. Biochem J 2021; 478:135-156. [PMID: 33439989 DOI: 10.1042/bcj20200066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 12/10/2020] [Accepted: 12/15/2020] [Indexed: 12/14/2022]
Abstract
Genomic integrity is most threatened by double-strand breaks, which, if left unrepaired, lead to carcinogenesis or cell death. The cell generates a network of protein-protein signaling interactions that emanate from the DNA damage which are now recognized as a rich basis for anti-cancer therapy development. Deciphering the structures of signaling proteins has been an uphill task owing to their large size and complex domain organization. Recent advances in mammalian protein expression/purification and cryo-EM-based structure determination have led to significant progress in our understanding of these large multidomain proteins. This review is an overview of the structural principles that underlie some of the key signaling proteins that function at the double-strand break site. We also discuss some plausible ideas that could be considered for future structural approaches to visualize and build a more complete understanding of protein dynamics at the break site.
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Affiliation(s)
- Rashmi Panigrahi
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - J N Mark Glover
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
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31
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Yu L, Lang Y, Guo J, Cai J, Shang ZF, Chen BPC. DNA-PKcs inhibition impairs HDAC6-mediated HSP90 chaperone function on Aurora A and enhances HDACs inhibitor-induced cell killing by increasing mitotic aberrant spindle assembly. Cell Cycle 2021; 20:211-224. [PMID: 33404279 DOI: 10.1080/15384101.2020.1867790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Combining targeted therapeutic agents is an attractive cancer treatment strategy associated with high efficacy and low toxicity. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is an essential factor in DNA damage repair. Studies from us and others have revealed that DNA-PKcs also plays an important role in normal mitosis progression. Histone deacetylase (HDACs) inhibitors commonly lead to mitotic aberration and have been approved for treating various cancers in the clinic. We showed that DNA-PKcs depletion or kinase activity inhibition increases cancer cells' sensitivity to HDACs inhibitors in vitro and in vivo. DNA-PKcs deficiency significantly enhances HDACs inhibitors (HDACi)-induced mitotic arrest and is followed by apoptotic cell death. Mechanistically, we found that DNA-PKcs binds to HDAC6 and facilitates its acetylase activity. HDACi is more likely to impair HDAC6-induced deacetylation of HSP90 and abrogate HSP90's chaperone function on Aurora A, a critical mitotic kinase that regulates centrosome separation and mitotic spindle assembly in DNA-PKcs-deficient cells. Our current work indicates crosstalk between DNA-PKcs and HDACs signaling pathways, and highlights that the combined targeting of DNA-PKcs and HDACs can be used in cancer therapy. Abbreviations: DNA-PKcs, DNA-dependent protein kinase catalytic subunit, HDACs, Histone deacetylases, DSBs, DNA double-strand breaks, ATM, ataxia telangiectasia mutated, ATR, ATM-Rad3-related.
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Affiliation(s)
- Lan Yu
- Department of Radiation Oncology, Simmons Comprehensive Cancer Center at UT Southwestern Medical Center , Dallas, TX, USA
| | - Yue Lang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University , Suzhou, China
| | - Jiaming Guo
- Department of Radiation Oncology, Simmons Comprehensive Cancer Center at UT Southwestern Medical Center , Dallas, TX, USA.,Department of Radiation Medicine, College of Naval Medicine, Naval Medical University , Shanghai, China
| | - Jianming Cai
- Department of Radiation Medicine, College of Naval Medicine, Naval Medical University , Shanghai, China
| | - Zeng-Fu Shang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University , Suzhou, China
| | - Benjamin P C Chen
- Department of Radiation Oncology, Simmons Comprehensive Cancer Center at UT Southwestern Medical Center , Dallas, TX, USA
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32
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LncRNA linc00312 suppresses radiotherapy resistance by targeting DNA-PKcs and impairing DNA damage repair in nasopharyngeal carcinoma. Cell Death Dis 2021; 12:69. [PMID: 33431817 PMCID: PMC7801696 DOI: 10.1038/s41419-020-03302-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 11/28/2020] [Accepted: 12/01/2020] [Indexed: 02/05/2023]
Abstract
Radioresistance is the main obstacle in the clinical management of nasopharyngeal carcinoma (NPC). linc00312 is deregulated in a number of human cancers, including NPC. However, the detailed functions and underlying mechanisms of linc00312 in regulating radiosensitivity of NPC remains unknown. In this study, cox regression analysis was used to assess the association between linc00312 and NPC patients’ survival after radiotherapy. Our results reveal that linc00312 is significantly down-regulated in NPC tissues and patients with higher expression of linc00312 are significantly associated with longer overall survival and better short-term radiotherapy efficacy. Overexpression of linc00312 could increase the sensitivity of NPC cells to ionizing radiation, as indicated by clonogenic survival assay, comet assay, and flow cytometry. Mechanistically, RNA pull down and RNA immunoprecipitation were performed to investigate the binding proteins of linc00312. linc00312 directly binds to DNA-PKcs, hinders the recruitment of DNA-PKcs to Ku80, and inhibits phosphorylation of AKT–DNA–PKcs axis, therefore inhibiting the DNA damage signal sensation and transduction in the NHEJ repair pathway. In addition, linc00312 impairs DNA repair and cell cycle control by suppressing MRN–ATM–CHK2 signal and ATR–CHK1 signal. In summary, we identified DNA-PKcs as the binding protein of linc00312 and revealed a novel mechanism of linc00312 in the DNA damage response, providing evidence for a potential therapeutic strategy in NPC.
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Nickoloff JA, Taylor L, Sharma N, Kato TA. Exploiting DNA repair pathways for tumor sensitization, mitigation of resistance, and normal tissue protection in radiotherapy. CANCER DRUG RESISTANCE (ALHAMBRA, CALIF.) 2021; 4:244-263. [PMID: 34337349 PMCID: PMC8323830 DOI: 10.20517/cdr.2020.89] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
More than half of cancer patients are treated with radiotherapy, which kills tumor cells by directly and indirectly inducing DNA damage, including cytotoxic DNA double-strand breaks (DSBs). Tumor cells respond to these threats by activating a complex signaling network termed the DNA damage response (DDR). The DDR arrests the cell cycle, upregulates DNA repair, and triggers apoptosis when damage is excessive. The DDR signaling and DNA repair pathways are fertile terrain for therapeutic intervention. This review highlights strategies to improve therapeutic gain by targeting DDR and DNA repair pathways to radiosensitize tumor cells, overcome intrinsic and acquired tumor radioresistance, and protect normal tissue. Many biological and environmental factors determine tumor and normal cell responses to ionizing radiation and genotoxic chemotherapeutics. These include cell type and cell cycle phase distribution; tissue/tumor microenvironment and oxygen levels; DNA damage load and quality; DNA repair capacity; and susceptibility to apoptosis or other active or passive cell death pathways. We provide an overview of radiobiological parameters associated with X-ray, proton, and carbon ion radiotherapy; DNA repair and DNA damage signaling pathways; and other factors that regulate tumor and normal cell responses to radiation. We then focus on recent studies exploiting DSB repair pathways to enhance radiotherapy therapeutic gain.
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Affiliation(s)
- Jac A. Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
- Correspondence Address: Dr. Jac A. Nickoloff, Department of Environmental and Radiological Health Sciences, Colorado State University, 1681 Campus Delivery, Ft. Collins, CO 80523-1681, USA. E-mail:
| | - Lynn Taylor
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Neelam Sharma
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Takamitsu A. Kato
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
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Structural insights into the role of DNA-PK as a master regulator in NHEJ. GENOME INSTABILITY & DISEASE 2021; 2:195-210. [PMID: 34723130 PMCID: PMC8549938 DOI: 10.1007/s42764-021-00047-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/06/2021] [Accepted: 07/12/2021] [Indexed: 12/26/2022]
Abstract
DNA-dependent protein kinase catalytic subunit DNA-PKcs/PRKDC is the largest serine/threonine protein kinase of the phosphatidyl inositol 3-kinase-like protein kinase (PIKK) family and is the most highly expressed PIKK in human cells. With its DNA-binding partner Ku70/80, DNA-PKcs is required for regulated and efficient repair of ionizing radiation-induced DNA double-strand breaks via the non-homologous end joining (NHEJ) pathway. Loss of DNA-PKcs or other NHEJ factors leads to radiation sensitivity and unrepaired DNA double-strand breaks (DSBs), as well as defects in V(D)J recombination and immune defects. In this review, we highlight the contributions of the late Dr. Carl W. Anderson to the discovery and early characterization of DNA-PK. We furthermore build upon his foundational work to provide recent insights into the structure of NHEJ synaptic complexes, an evolutionarily conserved and functionally important YRPD motif, and the role of DNA-PKcs and its phosphorylation in NHEJ. The combined results identify DNA-PKcs as a master regulator that is activated by its detection of two double-strand DNA ends for a cascade of phosphorylation events that provide specificity and efficiency in assembling the synaptic complex for NHEJ.
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Yue X, Bai C, Xie D, Ma T, Zhou PK. DNA-PKcs: A Multi-Faceted Player in DNA Damage Response. Front Genet 2020; 11:607428. [PMID: 33424929 PMCID: PMC7786053 DOI: 10.3389/fgene.2020.607428] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/01/2020] [Indexed: 12/17/2022] Open
Abstract
DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a member of the phosphatidylinositol 3-kinase related kinase family, which can phosphorylate more than 700 substrates. As the core enzyme, DNA-PKcs forms the active DNA-PK holoenzyme with the Ku80/Ku70 heterodimer to play crucial roles in cellular DNA damage response (DDR). Once DNA double strand breaks (DSBs) occur in the cells, DNA-PKcs is promptly recruited into damage sites and activated. DNA-PKcs is auto-phosphorylated and phosphorylated by Ataxia-Telangiectasia Mutated at multiple sites, and phosphorylates other targets, participating in a series of DDR and repair processes, which determine the cells' fates: DSBs NHEJ repair and pathway choice, replication stress response, cell cycle checkpoints, telomeres length maintenance, senescence, autophagy, etc. Due to the special and multi-faceted roles of DNA-PKcs in the cellular responses to DNA damage, it is important to precisely regulate the formation and dynamic of its functional complex and activities for guarding genomic stability. On the other hand, targeting DNA-PKcs has been considered as a promising strategy of exploring novel radiosensitizers and killing agents of cancer cells. Combining DNA-PKcs inhibitors with radiotherapy can effectively enhance the efficacy of radiotherapy, offering more possibilities for cancer therapy.
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Affiliation(s)
- Xiaoqiao Yue
- School of Public Health, University of South China, Hengyang, China.,Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Chenjun Bai
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Dafei Xie
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Teng Ma
- Department of Cellular and Molecular Biology, Beijing Chest Hospital, Capital Medical University/Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China
| | - Ping-Kun Zhou
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, China
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Neal JA, Dunger K, Geith K, Meek K. Deciphering the role of distinct DNA-PK phosphorylations at collapsed replication forks. DNA Repair (Amst) 2020; 94:102925. [PMID: 32674014 PMCID: PMC7494621 DOI: 10.1016/j.dnarep.2020.102925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 06/29/2020] [Accepted: 07/06/2020] [Indexed: 11/29/2022]
Abstract
It has recently been established that the marked sensitivity of ATM deficient cells to topoisomerase poisons like camptothecin (Cpt) results from unrestrained end-joining of DNA ends at collapsed replication forks that is mediated by the non-homologous end joining [NHEJ] pathway and results in the induction of copious numbers of genomic alterations, termed "toxic NHEJ". Ablation of core components of the NHEJ pathway reverses the Cpt sensitivity of ATM deficient cells, but inhibition of DNA-PKcs does not. Here, we show that complete ablation of DNA-PKcs partially reverses the Cpt sensitivity of ATM deficient cells; thus, ATM deficient cells lacking DNA-PKcs are more resistant to Cpt than cells expressing DNA-PKcs. However, the relative sensitivity of DNA-PKcs proficient ATM deficient cells is inversely proportional to DNA-PKcs expression levels. These data suggest that DNA-PK may phosphorylate an ATM target (that contributes to Cpt resistance), explaining partial rescue of Cpt sensitivity in cells expressing high levels of DNA-PKcs. Although crippling NHEJ function by mutagenic blockade of the critical ABCDE autophosphorylation sites in DNA-PKcs also sensitizes cells to Cpt, this sensitization apparently occurs by a distinct mechanism from ATM ablation because blockade of these sites actually rescues ATM deficient cells from toxic NHEJ. These data are consistent with autophosphorylation of the ABCDE sites (and not ATM mediated phosphorylation) in response to Cpt-induced damage. In contrast, blockade of S3205 (an ATM dependent phosphorylation site in DNA-PKcs) that minimally impacts NHEJ, increases Cpt sensitivity. In sum, these data suggest that ATM and DNA-PK cooperate to facilitate Cpt-induced DNA damage, and that ATM phosphorylation of S3205 facilitates appropriate repair at collapsed replication forks.
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Affiliation(s)
- Jessica A Neal
- College of Veterinary Medicine, Department of Microbiology & Molecular Genetics, Department of Pathobiology & Diagnostic Investigation, Michigan State University, East Lansing, MI 48824, USA
| | - Krista Dunger
- College of Veterinary Medicine, Department of Microbiology & Molecular Genetics, Department of Pathobiology & Diagnostic Investigation, Michigan State University, East Lansing, MI 48824, USA
| | - Kelly Geith
- College of Veterinary Medicine, Department of Microbiology & Molecular Genetics, Department of Pathobiology & Diagnostic Investigation, Michigan State University, East Lansing, MI 48824, USA
| | - Katheryn Meek
- College of Veterinary Medicine, Department of Microbiology & Molecular Genetics, Department of Pathobiology & Diagnostic Investigation, Michigan State University, East Lansing, MI 48824, USA.
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Britton S, Chanut P, Delteil C, Barboule N, Frit P, Calsou P. ATM antagonizes NHEJ proteins assembly and DNA-ends synapsis at single-ended DNA double strand breaks. Nucleic Acids Res 2020; 48:9710-9723. [PMID: 32890395 PMCID: PMC7515714 DOI: 10.1093/nar/gkaa723] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 07/29/2020] [Accepted: 08/21/2020] [Indexed: 12/15/2022] Open
Abstract
Two DNA repair pathways operate at DNA double strand breaks (DSBs): non-homologous end-joining (NHEJ), that requires two adjacent DNA ends for ligation, and homologous recombination (HR), that resects one DNA strand for invasion of a homologous duplex. Faithful repair of replicative single-ended DSBs (seDSBs) is mediated by HR, due to the lack of a second DNA end for end-joining. ATM stimulates resection at such breaks through multiple mechanisms including CtIP phosphorylation, which also promotes removal of the DNA-ends sensor and NHEJ protein Ku. Here, using a new method for imaging the recruitment of the Ku partner DNA-PKcs at DSBs, we uncover an unanticipated role of ATM in removing DNA-PKcs from seDSBs in human cells. Phosphorylation of DNA-PKcs on the ABCDE cluster is necessary not only for DNA-PKcs clearance but also for the subsequent MRE11/CtIP-dependent release of Ku from these breaks. We propose that at seDSBs, ATM activity is necessary for the release of both Ku and DNA-PKcs components of the NHEJ apparatus, and thereby prevents subsequent aberrant interactions between seDSBs accompanied by DNA-PKcs autophosphorylation and detrimental commitment to Lig4-dependent end-joining.
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Affiliation(s)
- Sébastien Britton
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue contre le Cancer 2018, Toulouse, France
| | - Pauline Chanut
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue contre le Cancer 2018, Toulouse, France
| | - Christine Delteil
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue contre le Cancer 2018, Toulouse, France
| | - Nadia Barboule
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue contre le Cancer 2018, Toulouse, France
| | - Philippe Frit
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue contre le Cancer 2018, Toulouse, France
| | - Patrick Calsou
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Equipe Labellisée Ligue contre le Cancer 2018, Toulouse, France
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Inhibition of non-homologous end joining of gamma ray-induced DNA double-strand breaks by cAMP signaling in lung cancer cells. Sci Rep 2020; 10:14455. [PMID: 32879366 PMCID: PMC7468279 DOI: 10.1038/s41598-020-71522-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 08/17/2020] [Indexed: 02/08/2023] Open
Abstract
DNA double-strand breaks (DSB) are formed by various exogenous and endogenous factors and are repaired by homologous recombination and non-homologous end joining (NHEJ). DNA-dependent protein kinase (DNA-PK) is the principal enzyme for NHEJ. We explored the role and the underlying mechanism of cAMP signaling in the NHEJ repair of DSBs resulted from gamma ray irradiation to non-small cell lung cancer (NSLC) cells. Activated cAMP signaling by expression of an activated stimulatory GTP-binding protein or by pretreatment with isoproterenol and prostaglandin E2, delayed the repair of DSBs resulted from gamma ray irradiation, and the delaying effects depended on protein kinase A (PKA). Activated cAMP signaling suppressed XRCC4 and DNA ligase IV recruitment into DSB foci, and reduced phosphorylation at T2609 in DNA-PK catalytic subunit (DNA-PKcs) with a concomitant increase in phosphorylation at S2056 in PKA-dependent ways following gamma ray irradiation. cAMP signaling decreased phosphorylation of T2609 by protein phosphatase 2A-dependent inhibition of ATM. We conclude that cAMP signaling delays the repair of gamma ray-induced DNA DSBs in NSLC cells by inhibiting NHEJ via PKA-dependent pathways, and that cAMP signaling differentially modulates DNA-PKcs phosphorylation at S2056 and T2609, which might contribute to the inhibition of NHEJ in NSLC cells.
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DNA-PKcs phosphorylation at the T2609 cluster alters the repair pathway choice during immunoglobulin class switch recombination. Proc Natl Acad Sci U S A 2020; 117:22953-22961. [PMID: 32868446 DOI: 10.1073/pnas.2007455117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The DNA-dependent protein kinase (DNA-PK), which is composed of the KU heterodimer and the large catalytic subunit (DNA-PKcs), is a classical nonhomologous end-joining (cNHEJ) factor. Naïve B cells undergo class switch recombination (CSR) to generate antibodies with different isotypes by joining two DNA double-strand breaks at different switching regions via the cNHEJ pathway. DNA-PK and the cNHEJ pathway play important roles in the DNA repair phase of CSR. To initiate cNHEJ, KU binds to DNA ends and recruits and activates DNA-PK. Activated DNA-PK phosphorylates DNA-PKcs at the S2056 and T2609 clusters. Loss of T2609 cluster phosphorylation increases radiation sensitivity but whether T2609 phosphorylation has a role in physiological DNA repair remains elusive. Using the DNA-PKcs 5A mouse model carrying alanine substitutions at the T2609 cluster, here we show that loss of T2609 phosphorylation of DNA-PKcs does not affect the CSR efficiency. Yet, the CSR junctions recovered from DNA-PKcs 5A/5A B cells reveal increased chromosomal translocations, extensive use of distal switch regions (consistent with end resection), and preferential usage of microhomology-all signs of the alternative end-joining pathway. Thus, these results uncover a role of DNA-PKcs T2609 phosphorylation in promoting cNHEJ repair pathway choice during CSR.
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40
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DNA-PK in human malignant disorders: Mechanisms and implications for pharmacological interventions. Pharmacol Ther 2020; 215:107617. [PMID: 32610116 DOI: 10.1016/j.pharmthera.2020.107617] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/15/2020] [Indexed: 12/12/2022]
Abstract
The DNA-PK holoenzyme is a fundamental element of the DNA damage response machinery (DDR), which is responsible for cellular genomic stability. Consequently, and predictably, over the last decades since its identification and characterization, numerous pre-clinical and clinical studies reported observations correlating aberrant DNA-PK status and activity with cancer onset, progression and responses to therapeutic modalities. Notably, various studies have established in recent years the role of DNA-PK outside the DDR network, corroborating its role as a pleiotropic complex involved in transcriptional programs that operate biologic processes as epithelial to mesenchymal transition (EMT), hypoxia, metabolism, nuclear receptors signaling and inflammatory responses. In particular tumor entities as prostate cancer, immense research efforts assisted mapping and describing the overall signaling networks regulated by DNA-PK that control metastasis and tumor progression. Correspondingly, DNA-PK emerges as an obvious therapeutic target in cancer and data pertaining to various pharmacological approaches have been published, largely in context of combination with DNA-damaging agents (DDAs) that act by inflicting DNA double strand breaks (DSBs). Currently, new generation inhibitors are tested in clinical trials. Several excellent reviews have been published in recent years covering the biology of DNA-PK and its role in cancer. In the current article we are aiming to systematically describe the main findings on DNA-PK signaling in major cancer types, focusing on both preclinical and clinical reports and present a detailed current status of the DNA-PK inhibitors repertoire.
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41
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Wang XS, Lee BJ, Zha S. The recent advances in non-homologous end-joining through the lens of lymphocyte development. DNA Repair (Amst) 2020; 94:102874. [PMID: 32623318 DOI: 10.1016/j.dnarep.2020.102874] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/16/2020] [Accepted: 05/24/2020] [Indexed: 12/17/2022]
Abstract
Lymphocyte development requires ordered assembly and subsequent modifications of the antigen receptor genes through V(D)J recombination and Immunoglobulin class switch recombination (CSR), respectively. While the programmed DNA cleavage events are initiated by lymphocyte-specific factors, the resulting DNA double-strand break (DSB) intermediates activate the ATM kinase-mediated DNA damage response (DDR) and rely on the ubiquitously expressed classical non-homologous end-joining (cNHEJ) pathway including the DNA-dependent protein kinase (DNA-PK), and, in the case of CSR, also the alternative end-joining (Alt-EJ) pathway, for repair. Correspondingly, patients and animal models with cNHEJ or DDR defects develop distinct types of immunodeficiency reflecting their specific DNA repair deficiency. The unique end-structure, sequence context, and cell cycle regulation of V(D)J recombination and CSR also provide a valuable platform to study the mechanisms of, and the interplay between, cNHEJ and DDR. Here, we compare and contrast the genetic consequences of DNA repair defects in V(D)J recombination and CSR with a focus on the newly discovered cNHEJ factors and the kinase-dependent structural roles of ATM and DNA-PK in animal models. Throughout, we try to highlight the pending questions and emerging differences that will extend our understanding of cNHEJ and DDR in the context of primary immunodeficiency and lymphoid malignancies.
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Affiliation(s)
- Xiaobin S Wang
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Graduate Program of Pathobiology and Molecular Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States
| | - Brian J Lee
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States
| | - Shan Zha
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Immunology and Microbiology, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States.
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Triptolide impairs genome integrity by directly blocking the enzymatic activity of DNA-PKcs in human cells. Biomed Pharmacother 2020; 129:110427. [PMID: 32574974 DOI: 10.1016/j.biopha.2020.110427] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/09/2020] [Accepted: 06/13/2020] [Indexed: 01/02/2023] Open
Abstract
Triptolide is a multi-functional natural small molecular compound extracted from a traditional Chinese medicinal herb. Triptolide and its derivatives exhibit cytotoxicity through inducing DNA damage, therefore increasing sensitivity to DNA-damage based chemotherapy or radiotherapy in different types of cells. However, the regulatory mechanism of genotoxicity by triptolide, and the loss of genome integrity induced by triptolide are not fully understood. Here, we measured the effects of triptolide on genome integrity in a human fibroblast line HCA2-hTERT using the neutral comet assay. We demonstrated that treating cells with triptolide induced genomic instability in HCA2-hTERT cells. Furthermore, we observed the accumulation of γH2AX foci in triptolide treated cells than control cells at 24 h post ionizing radiation. Further mechanistic studies indicated that triptolide inhibited the enzymatic activity of DNA-PKcs, the critical nonhomologous end joining factor. In vitro kinase activity assays showed that triptolide suppressed the kinase activity of DNA-PKcs and molecular docking also predicted a potential interaction between triptolide and DNA-PKcs. As a consequence, we found that triptolide treatment enhanced the interaction between DNA-PKcs and KU80 and hampered the following recruitment of 53BP1. Altogether, our finding provides a new perspective about the toxicity of triptolide in non-cancer cells and highlights the necessity of taking genome effects of triptolide and its derivatives into consideration in the future clinical and research applications.
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Guo Z, Wang S, Xie Y, Han Y, Hu S, Guan H, Xie D, Bai C, Liu X, Gu Y, Zhou PK, Ma T. HUWE1-dependent DNA-PKcs neddylation modulates its autophosphorylation in DNA damage response. Cell Death Dis 2020; 11:400. [PMID: 32457294 PMCID: PMC7250858 DOI: 10.1038/s41419-020-2611-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 05/07/2020] [Accepted: 05/11/2020] [Indexed: 02/07/2023]
Abstract
DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is the core component of DNA-PK complex in the non-homologous end-joining (NHEJ) repair of DNA double-strand breaks, and its activity is strictly controlled by DNA-PKcs phosphorylation. The ubiquitin-like protein, NEDD8 is involved in regulation of DNA damage response, but it remains mysterious whether and how NEDD8-related neddylation affects DNA-PKcs and the NHEJ process. Here, we show that DNA-PKcs is poly-neddylated at its kinase domain. The neddylation E2-conjugating enzyme UBE2M and E3 ligase HUWE1 (HECT, UBA, and WWE domain containing E3 ubiquitin protein ligase 1) are responsible for the DNA-PKcs neddylation. Moreover, inhibition of HUWE1-dependent DNA-PKcs neddylation impairs DNA-PKcs autophosphorylation at Ser2056. Finally, depletion of HUWE1-dependent DNA-PKcs neddylation reduces the efficiency of NHEJ. These studies provide insights how neddylation modulates the activity of NHEJ core complex.
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Affiliation(s)
- Zongpei Guo
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China
| | - Shaozheng Wang
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China
| | - Ying Xie
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China
| | - Yang Han
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China.,Institute for Environmental Medicine and Radiation Hygiene, School of Public Health, University of South China, Hengyang, Hunan Province, 421001, P. R. China
| | - Sai Hu
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China.,Institute for Environmental Medicine and Radiation Hygiene, School of Public Health, University of South China, Hengyang, Hunan Province, 421001, P. R. China
| | - Hua Guan
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China
| | - Dafei Xie
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China
| | - Chenjun Bai
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China
| | - Xiaodan Liu
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China
| | - Yongqing Gu
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China
| | - Ping-Kun Zhou
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China. .,Institute for Environmental Medicine and Radiation Hygiene, School of Public Health, University of South China, Hengyang, Hunan Province, 421001, P. R. China.
| | - Teng Ma
- Department of Radiation Toxicology and Oncology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, Beijing, 100850, P. R. China. .,Department of Cellular and Molecular Biology, Beijing Chest Hospital, Capital Medical University/Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, 101149, P. R. China.
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Lochab S, Singh Y, Sengupta S, Nandicoori VK. Mycobacterium tuberculosis exploits host ATM kinase for survival advantage through SecA2 secretome. eLife 2020; 9:51466. [PMID: 32223892 PMCID: PMC7162654 DOI: 10.7554/elife.51466] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 03/27/2020] [Indexed: 11/13/2022] Open
Abstract
(Mtb) produces inflections in the host signaling networks to create a favorable milieu for survival. The virulent Mtb strain, Rv caused double strand breaks (DSBs), whereas the non-virulent Ra strain triggered single-stranded DNA generation. The effectors secreted by SecA2 pathway were essential and adequate for the genesis of DSBs. Accumulation of DSBs mediated through Rv activates ATM-Chk2 pathway of DNA damage response (DDR) signaling, resulting in altered cell cycle. Instead of the classical ATM-Chk2 DDR, Mtb gains survival advantage through ATM-Akt signaling cascade. Notably, in vivo infection with Mtb led to sustained DSBs and ATM activation during chronic phase of tuberculosis. Addition of ATM inhibitor enhances isoniazid mediated Mtb clearance in macrophages as well as in murine infection model, suggesting its utility for host directed adjunct therapy. Collectively, data suggests that DSBs inflicted by SecA2 secretome of Mtb provides survival niche through activation of ATM kinase.
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Affiliation(s)
- Savita Lochab
- National Institute of Immunology, New Delhi, India.,Department of Zoology, University of Delhi, New Delhi, India
| | - Yogendra Singh
- Department of Zoology, University of Delhi, New Delhi, India
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Radiation resistance in head and neck squamous cell carcinoma: dire need for an appropriate sensitizer. Oncogene 2020; 39:3638-3649. [PMID: 32157215 PMCID: PMC7190570 DOI: 10.1038/s41388-020-1250-3] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 02/18/2020] [Accepted: 02/25/2020] [Indexed: 01/11/2023]
Abstract
Radiation is a significant treatment for patients with head and neck cancer. Despite advances to improve treatment, many tumors acquire radiation resistance resulting in poor survival. Radiation kills cancer cells by inducing DNA double-strand breaks. Therefore, radiation resistance is enhanced by efficient repair of damaged DNA. Head and neck cancers overexpress EGFR and have a high frequency of p53 mutations, both of which enhance DNA repair. This review discusses the clinical criteria for radiation resistance in patients with head and neck cancer and summarizes how cancer cells evade radiation-mediated apoptosis by p53- and epidermal growth factor receptor (EGFR)-mediated DNA repair. In addition, we explore the role of cancer stem cells in promoting radiation resistance, and how the abscopal effect provides rationale for combination strategies with immunotherapy.
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The X-linked trichothiodystrophy-causing gene RNF113A links the spliceosome to cell survival upon DNA damage. Nat Commun 2020; 11:1270. [PMID: 32152280 PMCID: PMC7062854 DOI: 10.1038/s41467-020-15003-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 02/17/2020] [Indexed: 12/30/2022] Open
Abstract
Prolonged cell survival occurs through the expression of specific protein isoforms generated by alternate splicing of mRNA precursors in cancer cells. How alternate splicing regulates tumor development and resistance to targeted therapies in cancer remain poorly understood. Here we show that RNF113A, whose loss-of-function causes the X-linked trichothiodystrophy, is overexpressed in lung cancer and protects from Cisplatin-dependent cell death. RNF113A is a RNA-binding protein which regulates the splicing of multiple candidates involved in cell survival. RNF113A deficiency triggers cell death upon DNA damage through multiple mechanisms, including apoptosis via the destabilization of the prosurvival protein MCL-1, ferroptosis due to enhanced SAT1 expression, and increased production of ROS due to altered Noxa1 expression. RNF113A deficiency circumvents the resistance to Cisplatin and to BCL-2 inhibitors through the destabilization of MCL-1, which thus defines spliceosome inhibitors as a therapeutic approach to treat tumors showing acquired resistance to specific drugs due to MCL-1 stabilization. Alternate splicing of mRNA precursors has been linked to tumor development. Here the authors reveal a role of the E3 ligase RNF113A in spliceosome regulation affecting cell survival upon DNA damage.
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Dual PI3K/mTOR Inhibitor NVP-BEZ235 Enhances Radiosensitivity of Head and Neck Squamous Cell Carcinoma (HNSCC) Cell Lines Due to Suppressed Double-Strand Break (DSB) Repair by Non-Homologous End Joining. Cancers (Basel) 2020; 12:cancers12020467. [PMID: 32085396 PMCID: PMC7072694 DOI: 10.3390/cancers12020467] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/27/2020] [Accepted: 02/07/2020] [Indexed: 12/24/2022] Open
Abstract
The PI3K/Akt/mTOR pathway is frequently altered in human papillomavirus (HPV)-positive and negative squamous cell carcinoma of the head and neck (HNSCC) and overstimulation is associated with poor prognosis. PI3K drives Akt activation and constitutive signaling acts pro-proliferative, supports cell survival, DNA repair, and contributes to radioresistance. Since the small molecule NVP-BEZ235 (BEZ235) is a potent dual inhibitor of this pathway, we were interested whether BEZ235 could be an efficient radiosensitizer. The 50 nM BEZ235 was found to abrogate endogenous and irradiation-induced phosphorylation of Akt (Ser473). The anti-proliferative capacity of the drug resulted in an increase in G1-phase cells. Repair of radiation-induced DNA double-strand breaks (DSBs) was strongly suppressed. Reduction in DSB repair was only apparent in G1- but not in G2-phase cells, suggesting that BEZ235 primarily affects non-homologous end joining. This finding was confirmed using a DSB repair reporter gene assay and could be attributed to an impaired phosphorylation of DNA-PKcs (S2056). Cellular radiosensitivity increased strongly after BEZ235 addition in all HNSCC cell lines used, especially when irradiated in the G0 or G1 phase. Our data indicate that targeting the PI3K/Akt/mTOR pathway by BEZ235 with concurrent radiotherapy may be considered an effective strategy for the treatment of HNSCC, regardless of the HPV and Akt status.
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Klinakis A, Karagiannis D, Rampias T. Targeting DNA repair in cancer: current state and novel approaches. Cell Mol Life Sci 2020; 77:677-703. [PMID: 31612241 PMCID: PMC11105035 DOI: 10.1007/s00018-019-03299-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 08/06/2019] [Accepted: 09/09/2019] [Indexed: 12/12/2022]
Abstract
DNA damage response, DNA repair and genomic instability have been under study for their role in tumor initiation and progression for many years now. More recently, next-generation sequencing on cancer tissue from various patient cohorts have revealed mutations and epigenetic silencing of various genes encoding proteins with roles in these processes. These findings, together with the unequivocal role of DNA repair in therapeutic response, have fueled efforts toward the clinical exploitation of research findings. The successful example of PARP1/2 inhibitors has also supported these efforts and led to numerous preclinical and clinical trials with a large number of small molecules targeting various components involved in DNA repair singularly or in combination with other therapies. In this review, we focus on recent considerations related to DNA damage response and new DNA repair inhibition agents. We then discuss how immunotherapy can collaborate with these new drugs and how epigenetic drugs can rewire the activity of repair pathways and sensitize cancer cells to DNA repair inhibition therapies.
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Affiliation(s)
- Apostolos Klinakis
- Biomedical Research Foundation of the Academy of Athens, 11527, Athens, Greece.
| | - Dimitris Karagiannis
- Department of Genetics and Development, Columbia University Medical Center, New York, NY, 10032, USA
| | - Theodoros Rampias
- Biomedical Research Foundation of the Academy of Athens, 11527, Athens, Greece.
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Menolfi D, Zha S. ATM, ATR and DNA-PKcs kinases-the lessons from the mouse models: inhibition ≠ deletion. Cell Biosci 2020; 10:8. [PMID: 32015826 PMCID: PMC6990542 DOI: 10.1186/s13578-020-0376-x] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 01/14/2020] [Indexed: 01/11/2023] Open
Abstract
DNA damage, especially DNA double strand breaks (DSBs) and replication stress, activates a complex post-translational network termed DNA damage response (DDR). Our review focuses on three PI3-kinase related protein kinases-ATM, ATR and DNA-PKcs, which situate at the apex of the mammalian DDR. They are recruited to and activated at the DNA damage sites by their respective sensor protein complexes-MRE11/RAD50/NBS1 for ATM, RPA/ATRIP for ATR and KU70-KU80/86 (XRCC6/XRCC5) for DNA-PKcs. Upon activation, ATM, ATR and DNA-PKcs phosphorylate a large number of partially overlapping substrates to promote efficient and accurate DNA repair and to coordinate DNA repair with other DNA metabolic events (e.g., transcription, replication and mitosis). At the organism level, robust DDR is critical for normal development, aging, stem cell maintenance and regeneration, and physiological genomic rearrangements in lymphocytes and germ cells. In addition to endogenous damage, oncogene-induced replication stresses and genotoxic chemotherapies also activate DDR. On one hand, DDR factors suppress genomic instability to prevent malignant transformation. On the other hand, targeting DDR enhances the therapeutic effects of anti-cancer chemotherapy, which led to the development of specific kinase inhibitors for ATM, ATR and DNA-PKcs. Using mouse models expressing kinase dead ATM, ATR and DNA-PKcs, an unexpected structural function of these kinases was revealed, where the expression of catalytically inactive kinases causes more genomic instability than the loss of the proteins themselves. The spectrum of genomic instabilities and physiological consequences are unique for each kinase and depends on their activating complexes, suggesting a model in which the catalysis is coupled with DNA/chromatin release and catalytic inhibition leads to the persistence of the kinases at the DNA lesion, which in turn affects repair pathway choice and outcomes. Here we discuss the experimental evidences supporting this mode of action and their implications in the design and use of specific kinase inhibitors for ATM, ATR and DNA-PKcs for cancer therapy.
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Affiliation(s)
- Demis Menolfi
- Institute for Cancer Genetics, College of Physicians & Surgeons, Columbia University, New York, NY 10032 USA
| | - Shan Zha
- Institute for Cancer Genetics, College of Physicians & Surgeons, Columbia University, New York, NY 10032 USA
- Department of Pathology and Cell Biology, College of Physicians & Surgeons, Columbia University, New York, NY 10032 USA
- Division of Pediatric Oncology, Hematology and Stem Cell Transplantation, Department of Pediatrics, College of Physicians & Surgeons, Columbia University, New York, NY 10032 USA
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Lacombe J, Cretignier T, Meli L, Wijeratne EMK, Veuthey JL, Cuendet M, Gunatilaka AAL, Zenhausern F. Withanolide D Enhances Radiosensitivity of Human Cancer Cells by Inhibiting DNA Damage Non-homologous End Joining Repair Pathway. Front Oncol 2020; 9:1468. [PMID: 31970089 PMCID: PMC6960174 DOI: 10.3389/fonc.2019.01468] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 12/09/2019] [Indexed: 01/09/2023] Open
Abstract
Along with surgery and chemotherapy, radiation therapy (RT) is an important modality in cancer treatment, and the development of radiosensitizers is a current key challenge in radiobiology to maximize RT efficiency. In this study, the radiosensitizing effect of a natural compound from the withanolide family, withanolide D (WD), was assessed. Clonogenic assays showed that a 1 h WD pretreatment (0.7 μM) before irradiation decreased the surviving fraction of several cancer cell lines. To determine the mechanisms by which WD achieved its radiosensitizing effect, we then assessed whether WD could promote radiation-induced DNA damages and inhibit double-strand breaks (DSBs) repair in SKOV3 cells. Comet and γH2AX/53BP1 foci formation assays confirmed that DSBs were higher between 1 and 24 h after 2 Gy-irradiation in WD-treated cells compared to vehicle-treated cells, suggesting that WD induced the persistence of radiation-induced DNA damages. Immunoblotting was then performed to investigate protein expression involved in DNA repair pathways. Interestingly, DNA-PKc, ATM, and their phosphorylated forms appeared to be inhibited 24 h post-irradiation in WD-treated samples. XRCC4 expression was also down-regulated while RAD51 expression did not change compared to vehicle-treated cells suggesting that only non-homologous end joining (NHEJ) pathways was inhibited by WD. Mitotic catastrophe (MC) was then investigated in SKOV3, a p53-deficient cell line, to assess the consequence of such inhibition. MC was induced after irradiation and was predominant in WD-treated samples as shown by the few numbers of cells pursuing into anaphase and the increased amount of bipolar metaphasic cells. Together, these data demonstrated that WD could be a promising radiosensitizer candidate for RT by inhibiting NHEJ pathway and promoting MC. Additional studies are required to better understand its efficiency and mechanism of action in more relevant clinical models.
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Affiliation(s)
- Jerome Lacombe
- Center for Applied NanoBioscience and Medicine, College of Medicine Phoenix, University of Arizona, Phoenix, AZ, United States
| | - Titouan Cretignier
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
| | - Laetitia Meli
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
| | - E M Kithsiri Wijeratne
- Southwest Center for Natural Products Research, School of Natural Resources & the Environment, College of Agriculture & Life Sciences, University of Arizona, Tucson, AZ, United States
| | - Jean-Luc Veuthey
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
| | - Muriel Cuendet
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
| | - A A Leslie Gunatilaka
- Southwest Center for Natural Products Research, School of Natural Resources & the Environment, College of Agriculture & Life Sciences, University of Arizona, Tucson, AZ, United States
| | - Frederic Zenhausern
- Center for Applied NanoBioscience and Medicine, College of Medicine Phoenix, University of Arizona, Phoenix, AZ, United States.,School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
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