1
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Luo Y, Niu M, Liu Y, Zhang M, Deng Y, Mu D, Xu J, Hong S. Oncoproteins E6 and E7 upregulate topoisomerase I to activate the cGAS-PD-L1 pathway in cervical cancer development. Front Pharmacol 2024; 15:1450875. [PMID: 39156107 PMCID: PMC11327024 DOI: 10.3389/fphar.2024.1450875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Accepted: 07/22/2024] [Indexed: 08/20/2024] Open
Abstract
Background: Cervical cancer (CC) stands as a significant health threat to women globally, with high-risk human papillomaviruses as major etiologic agents. The DNA damage repair (DDR) protein topoisomerase I (TOP1) has been linked to various cancers, yet its distinct roles and mechanisms in CC are not fully elucidated. Methods: We investigated TOP1 expression in cervical intraepithelial neoplasia (CIN) and CC tissues utilizing qRT-PCR and IHC, correlating findings with patient prognosis. Subsequent knockdown studies were performed in vitro and in vivo to evaluate the influence of TOP1 on tumor growth, DNA repair, and inflammatory responses. Results: TOP1 was highly expressed in CIN and CC, negatively correlating with patient prognosis. Inhibition of TOP1 impeded CC cell growth and disrupted DNA repair. TOP1 was shown to regulate tumor-promoting inflammation and programmed death-ligand 1 (PD-L1) production in a cGAS-dependent manner. HPV oncoproteins E6 and E7 upregulated TOP1 and activated the cGAS-PD-L1 pathway. Conclusions: TOP1 acts as a DNA repair mediator, promoting CC development and immune evasion. Targeting the TOP1-cGAS-PD-L1 axis could be a potential therapeutic strategy for CC.
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Affiliation(s)
- Ying Luo
- College of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Mengda Niu
- College of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Yanfei Liu
- College of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Miaochang Zhang
- College of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Yuanyuan Deng
- College of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Dan Mu
- College of Pharmacy, Chongqing Medical University, Chongqing, China
| | - Junfen Xu
- Department of Gynecologic Oncology, Women’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Shiyuan Hong
- College of Pharmacy, Chongqing Medical University, Chongqing, China
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2
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Swift LP, Lagerholm BC, Henderson LR, Ratnaweera M, Baddock HT, Sengerova B, Lee S, Cruz-Migoni A, Waithe D, Renz C, Ulrich HD, Newman JA, Schofield CJ, McHugh PJ. SNM1A is crucial for efficient repair of complex DNA breaks in human cells. Nat Commun 2024; 15:5392. [PMID: 38918391 PMCID: PMC11199599 DOI: 10.1038/s41467-024-49583-5] [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: 07/18/2023] [Accepted: 06/11/2024] [Indexed: 06/27/2024] Open
Abstract
DNA double-strand breaks (DSBs), such as those produced by radiation and radiomimetics, are amongst the most toxic forms of cellular damage, in part because they involve extensive oxidative modifications at the break termini. Prior to completion of DSB repair, the chemically modified termini must be removed. Various DNA processing enzymes have been implicated in the processing of these dirty ends, but molecular knowledge of this process is limited. Here, we demonstrate a role for the metallo-β-lactamase fold 5'-3' exonuclease SNM1A in this vital process. Cells disrupted for SNM1A manifest increased sensitivity to radiation and radiomimetic agents and show defects in DSB damage repair. SNM1A is recruited and is retained at the sites of DSB damage via the concerted action of its three highly conserved PBZ, PIP box and UBZ interaction domains, which mediate interactions with poly-ADP-ribose chains, PCNA and the ubiquitinated form of PCNA, respectively. SNM1A can resect DNA containing oxidative lesions induced by radiation damage at break termini. The combined results reveal a crucial role for SNM1A to digest chemically modified DNA during the repair of DSBs and imply that the catalytic domain of SNM1A is an attractive target for potentiation of radiotherapy.
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Affiliation(s)
- Lonnie P Swift
- Department of Oncology, MRC-Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - B Christoffer Lagerholm
- Wolfson Imaging Centre, MRC-Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
- Cell Imaging and Cytometry Core, Turku Bioscience Centre, University of Turku and Åbo Akademi, ku, Finland
| | - Lucy R Henderson
- Department of Oncology, MRC-Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Malitha Ratnaweera
- Department of Oncology, MRC-Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Hannah T Baddock
- Department of Oncology, MRC-Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
- Calico Life Sciences, South San Francisco, CA, USA
| | - Blanka Sengerova
- Department of Oncology, MRC-Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Sook Lee
- Department of Oncology, MRC-Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Abimael Cruz-Migoni
- Department of Oncology, MRC-Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Dominic Waithe
- Wolfson Imaging Centre, MRC-Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom
| | - Christian Renz
- Institute of Molecular Biology gGmbH (IMB), Mainz, Germany
| | - Helle D Ulrich
- Institute of Molecular Biology gGmbH (IMB), Mainz, Germany
| | - Joseph A Newman
- Centre for Medicines Discovery, University of Oxford, Oxford, United Kingdom
| | - Christopher J Schofield
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, Oxford, United Kingdom
| | - Peter J McHugh
- Department of Oncology, MRC-Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom.
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3
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Saha LK, Pommier Y. TOP3A coupling with replication forks and repair of TOP3A cleavage complexes. Cell Cycle 2024; 23:115-130. [PMID: 38341866 PMCID: PMC11037291 DOI: 10.1080/15384101.2024.2314440] [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: 08/25/2023] [Accepted: 01/08/2024] [Indexed: 02/13/2024] Open
Abstract
Humans have two Type IA topoisomerases, topoisomerase IIIα (TOP3A) and topoisomerase IIIβ (TOP3B). In this review, we focus on the role of human TOP3A in DNA replication and highlight the recent progress made in understanding TOP3A in the context of replication. Like other topoisomerases, TOP3A acts by a reversible mechanism of cleavage and rejoining of DNA strands allowing changes in DNA topology. By cleaving and resealing single-stranded DNA, it generates TOP3A-linked single-strand breaks as TOP3A cleavage complexes (TOP3Accs) with a TOP3A molecule covalently bound to the 5´-end of the break. TOP3A is critical for both mitochondrial and for nuclear DNA replication. Here, we discuss the formation and repair of irreversible TOP3Accs, as their presence compromises genome integrity as they form TOP3A DNA-protein crosslinks (TOP3A-DPCs) associated with DNA breaks. We discuss the redundant pathways that repair TOP3A-DPCs, and how their defects are a source of DNA damage leading to neurological diseases and mitochondrial disorders.
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Affiliation(s)
- Liton Kumar Saha
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Yves Pommier
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA
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4
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Rubio-Contreras D, Gómez-Herreros F. TDP1 suppresses chromosomal translocations and cell death induced by abortive TOP1 activity during gene transcription. Nat Commun 2023; 14:6940. [PMID: 37945566 PMCID: PMC10636166 DOI: 10.1038/s41467-023-42622-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 10/17/2023] [Indexed: 11/12/2023] Open
Abstract
DNA topoisomerase I (TOP1) removes torsional stress by transiently cutting one DNA strand. Such cuts are rejoined by TOP1 but can occasionally become abortive generating permanent protein-linked single strand breaks (SSBs). The repair of these breaks is initiated by tyrosyl-DNA phosphodiesterase 1 (TDP1), a conserved enzyme that unlinks the TOP1 peptide from the DNA break. Additionally, some of these SSBs can result in double strand breaks (DSBs) either during replication or by a poorly understood transcription-associated process. In this study, we identify these DSBs as a source of genome rearrangements, which are suppressed by TDP1. Intriguingly, we also provide a mechanistic explanation for the formation of chromosomal translocations unveiling an error-prone pathway that relies on the MRN complex and canonical non-homologous end-joining. Collectively, these data highlight the threat posed by TOP1-induced DSBs during transcription and demonstrate the importance of TDP1-dependent end-joining in protecting both gene transcription and genome stability.
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Affiliation(s)
- Diana Rubio-Contreras
- Instituto de Biomedicina de Sevilla, IBiS, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013, Seville, Spain
- Departamento de Genética, Universidad de Sevilla, 41012, Seville, Spain
| | - Fernando Gómez-Herreros
- Instituto de Biomedicina de Sevilla, IBiS, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013, Seville, Spain.
- Departamento de Genética, Universidad de Sevilla, 41012, Seville, Spain.
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5
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Guha Majumdar A, Shree S, Das A, Kumar BK, Dey P, Subramanian M, Patro BS. Design, synthesis and development of a dual inhibitor of Topoisomerase 1 and poly (ADP-ribose) polymerase 1 for efficient killing of cancer cells. Eur J Med Chem 2023; 258:115598. [PMID: 37406384 DOI: 10.1016/j.ejmech.2023.115598] [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: 05/05/2023] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 07/07/2023]
Abstract
Combinatorial inhibition of Topoisomerase 1 (TOP1) and Poly (ADP-ribose) polymerase 1 (PARP1) is an attractive therapeutic strategy which is under active investigation to address chemoresistance to TOP1 inhibitors. However, this combinatorial regimen suffers from severe dose limiting toxicities. Dual inhibitors often offer significant advantages over combinatorial therapies involving individual agents by minimizing toxicity and providing conducive pharmacokinetic profiles. In this study, we have designed, synthesized and evaluated a library of 11 candidate conjugated dual inhibitors for PARP1 and TOP1, named as DiPT-1 to DiPT-11. Our extensive screening showed that one of the hits i.e.DiPT-4 has promising cytotoxicity profile against multiple cancers with limited toxicities towards normal cells. DiPT-4 induces extensive DNA double stand breaks (DSBs), cell cycle arrest and apoptosis in cancer cells. Mechanistically, DiPT-4 has the propensity to bind catalytic pockets of TOP1 and PARP1, leading to significant inhibition of both TOP1 and PARP1 at in vitro and cellular level. Interestingly, DiPT-4 causes extensive stabilization of TOP1-DNA covalent complex (TOP1cc), a key lethal intermediate associated with induction of DSBs and cell death. Moreover, DiPT-4 inhibited poly (ADP-ribosylation) i.e. PARylation of TOP1cc, leading to long lived TOP1cc with a slower kinetics of degradation. This is one of the important molecular processes which helps in overcoming resistance in cancer in response to TOP1 inhibitors. Together, our investigation showed DiPT-4 as a promising dual inhibitor of TOP1 and PARP1, which may have the potential to offer significant advantages over combinatorial therapy in clinical settings.
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Affiliation(s)
- Ananda Guha Majumdar
- Bio-Organic Division, India; Homi Bhabha National Institute, Mumbai, Maharashtra, 400094, India
| | - Shikha Shree
- Bio-Organic Division, India; Homi Bhabha National Institute, Mumbai, Maharashtra, 400094, India
| | - Amit Das
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, 400085, India; Homi Bhabha National Institute, Mumbai, Maharashtra, 400094, India
| | - Binita K Kumar
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, 400085, India
| | | | - Mahesh Subramanian
- Bio-Organic Division, India; Homi Bhabha National Institute, Mumbai, Maharashtra, 400094, India
| | - Birija Sankar Patro
- Bio-Organic Division, India; Homi Bhabha National Institute, Mumbai, Maharashtra, 400094, India.
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6
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Saha LK, Saha S, Yang X, Huang SYN, Sun Y, Jo U, Pommier Y. Replication-associated formation and repair of human topoisomerase IIIα cleavage complexes. Nat Commun 2023; 14:1925. [PMID: 37024461 PMCID: PMC10079683 DOI: 10.1038/s41467-023-37498-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 03/08/2023] [Indexed: 04/08/2023] Open
Abstract
Topoisomerase IIIα (TOP3A) belongs to the conserved Type IA family of DNA topoisomerases. Here we report that human TOP3A is associated with DNA replication forks and that a "self-trapping" TOP3A mutant (TOP3A-R364W) generates cellular TOP3A DNA cleavage complexes (TOP3Accs). We show that trapped TOP3Accs that interfere with replication, induce DNA damage and genome instability. To elucidate how TOP3Accs are repaired, we explored the role of Spartan (SPRTN), the metalloprotease associated with DNA replication, which digests proteins forming DNA-protein crosslinks (DPCs). We find that SPRTN-deficient cells show elevated TOP3Accs, whereas overexpression of SPRTN lowers cellular TOP3Accs. SPRTN is deubiquitinated and epistatic with TDP2 in response to TOP3Accs. In addition, we found that MRE11 can excise TOP3Accs, and that cell cycle determines the preference for the SPRTN-TDP2 vs. the ATM-MRE11 pathways, in S vs. G2, respectively. Our study highlights the prevalence of TOP3Accs repair mechanisms to ensure normal DNA replication.
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Affiliation(s)
- Liton Kumar Saha
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Sourav Saha
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Xi Yang
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Shar-Yin Naomi Huang
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Yilun Sun
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Ukhyun Jo
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Yves Pommier
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, 20892, USA.
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7
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Otahalova B, Volkova Z, Soukupova J, Kleiblova P, Janatova M, Vocka M, Macurek L, Kleibl Z. Importance of Germline and Somatic Alterations in Human MRE11, RAD50, and NBN Genes Coding for MRN Complex. Int J Mol Sci 2023; 24:ijms24065612. [PMID: 36982687 PMCID: PMC10051278 DOI: 10.3390/ijms24065612] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/11/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023] Open
Abstract
The MRE11, RAD50, and NBN genes encode for the nuclear MRN protein complex, which senses the DNA double strand breaks and initiates the DNA repair. The MRN complex also participates in the activation of ATM kinase, which coordinates DNA repair with the p53-dependent cell cycle checkpoint arrest. Carriers of homozygous germline pathogenic variants in the MRN complex genes or compound heterozygotes develop phenotypically distinct rare autosomal recessive syndromes characterized by chromosomal instability and neurological symptoms. Heterozygous germline alterations in the MRN complex genes have been associated with a poorly-specified predisposition to various cancer types. Somatic alterations in the MRN complex genes may represent valuable predictive and prognostic biomarkers in cancer patients. MRN complex genes have been targeted in several next-generation sequencing panels for cancer and neurological disorders, but interpretation of the identified alterations is challenging due to the complexity of MRN complex function in the DNA damage response. In this review, we outline the structural characteristics of the MRE11, RAD50 and NBN proteins, the assembly and functions of the MRN complex from the perspective of clinical interpretation of germline and somatic alterations in the MRE11, RAD50 and NBN genes.
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Affiliation(s)
- Barbora Otahalova
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12800 Prague, Czech Republic
- Department of Biochemistry, Faculty of Natural Science, Charles University in Prague, 12800 Prague, Czech Republic
| | - Zuzana Volkova
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12800 Prague, Czech Republic
| | - Jana Soukupova
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12800 Prague, Czech Republic
| | - Petra Kleiblova
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12800 Prague, Czech Republic
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12800 Prague, Czech Republic
| | - Marketa Janatova
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12800 Prague, Czech Republic
| | - Michal Vocka
- Department of Oncology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12800 Prague, Czech Republic
| | - Libor Macurek
- Laboratory of Cancer Cell Biology, Institute of Molecular Genetics, Czech Academy of Sciences, 14220 Prague, Czech Republic
| | - Zdenek Kleibl
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12800 Prague, Czech Republic
- Institute of Pathological Physiology, First Faculty of Medicine and General University Hospital in Prague, 12853 Prague, Czech Republic
- Correspondence: ; Tel.: +420-22496-4287
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8
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The Lipophilic Purine Nucleoside-Tdp1 Inhibitor-Enhances DNA Damage Induced by Topotecan In Vitro and Potentiates the Antitumor Effect of Topotecan In Vivo. Molecules 2022; 28:molecules28010323. [PMID: 36615517 PMCID: PMC9822400 DOI: 10.3390/molecules28010323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/20/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023] Open
Abstract
The use of cancer chemotherapy sensitizers is a promising approach to induce the effect of clinically used anticancer treatments. One of the interesting targets is Tyrosyl-DNA Phosphodiesterase 1 (Tdp1), a DNA-repair enzyme, that may prevent the action of clinical Topoisomerase 1 (Top1) inhibitors, such as topotecan (Tpc). Tdp1 eliminates covalent Top1-DNA (Top1c) complexes that appear under the action of topotecan and determines the cytotoxic effect of this drug. We hypothesize that Tdp1 inhibition would sensitize cells towards the effect of Tpc. Herein, we report the synthesis and study of lipophilic derivatives of purine nucleosides that efficiently suppress Tdp1 activity, with IC50 values in the 0.3-22.0 μM range. We also showed that this compound class can enhance DNA damage induced by topotecan in vitro by Comet assay on human cell lines HeLa and potentiate the antitumor effect of topotecan in vivo on a mice ascitic Krebs-2 carcinoma model. Thereby, this type of compound may be useful to develop drugs, that sensitize the effect of topotecan and reduce the required dose and, as a result, side effects.
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9
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Meroni A, Grosser J, Agashe S, Ramakrishnan N, Jackson J, Verma P, Baranello L, Vindigni A. NEDDylated Cullin 3 mediates the adaptive response to topoisomerase 1 inhibitors. SCIENCE ADVANCES 2022; 8:eabq0648. [PMID: 36490343 PMCID: PMC9733930 DOI: 10.1126/sciadv.abq0648] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 10/26/2022] [Indexed: 05/30/2023]
Abstract
DNA topoisomerase 1 (TOP11) inhibitors are mainstays of anticancer therapy. These drugs trap TOP1 on DNA, stabilizing the TOP1-cleavage complex (TOP1-cc). The accumulation of TOP1-ccs perturbs DNA replication fork progression, leading to DNA breaks and cell death. By analyzing the genomic occupancy and activity of TOP1, we show that cells adapt to treatment with multiple doses of TOP1 inhibitor by promoting the degradation of TOP1-ccs, allowing cells to better tolerate subsequent doses of TOP1 inhibitor. The E3-RING Cullin 3 ligase in complex with the BTBD1 and BTBD2 adaptor proteins promotes TOP1-cc ubiquitination and subsequent proteasomal degradation. NEDDylation of Cullin 3 activates this pathway, and inhibition of protein NEDDylation or depletion of Cullin 3 sensitizes cancer cells to TOP1 inhibitors. Collectively, our data uncover a previously unidentified NEDD8-Cullin 3 pathway involved in the adaptive response to TOP1 inhibitors, which can be targeted to improve the efficacy of TOP1 drugs in cancer therapy.
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Affiliation(s)
- Alice Meroni
- Division of Oncology, Department of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Jan Grosser
- Karolinska Institutet, CMB, 171 65 Solna, Sweden
| | - Sumedha Agashe
- Division of Oncology, Department of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Natasha Ramakrishnan
- Division of Oncology, Department of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Jessica Jackson
- Division of Oncology, Department of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Priyanka Verma
- Division of Oncology, Department of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | | | - Alessandro Vindigni
- Division of Oncology, Department of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
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10
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TDP1-independent pathways in the process and repair of TOP1-induced DNA damage. Nat Commun 2022; 13:4240. [PMID: 35869071 PMCID: PMC9307636 DOI: 10.1038/s41467-022-31801-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 06/29/2022] [Indexed: 11/15/2022] Open
Abstract
Anticancer drugs, such as camptothecin (CPT), trap topoisomerase I (TOP1) on DNA and form TOP1 cleavage complexes (TOP1cc). Alternative repair pathways have been suggested in the repair of TOP1cc. However, how these pathways work with TDP1, a key repair enzyme that specifically hydrolyze the covalent bond between TOP1 catalytic tyrosine and the 3’-end of DNA and contribute to the repair of TOP1cc is poorly understood. Here, using unbiased whole-genome CRISPR screens and generation of co-deficient cells with TDP1 and other genes, we demonstrate that MUS81 is an important factor that mediates the generation of excess double-strand breaks (DSBs) in TDP1 KO cells. APEX1/2 are synthetic lethal with TDP1. However, deficiency of APEX1/2 does not reduce DSB formation in TDP1 KO cells. Together, our data suggest that TOP1cc can be either resolved directly by TDP1 or be converted into DSBs and repaired further by the Homologous Recombination (HR) pathway. Here the authors find that MUS81 mediates excess DNA double strand break (DSB) generation in TDP1 KO cells after camptothecin treatment. They show that TOP1 cleavage complexes can be either resolved directly by TDP1 or be converted into DSBs and repaired further by the Homologous Recombination pathway.
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11
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Perry M, Ghosal G. Mechanisms and Regulation of DNA-Protein Crosslink Repair During DNA Replication by SPRTN Protease. Front Mol Biosci 2022; 9:916697. [PMID: 35782873 PMCID: PMC9240642 DOI: 10.3389/fmolb.2022.916697] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 05/27/2022] [Indexed: 11/25/2022] Open
Abstract
DNA-protein crosslinks (DPCs) are deleterious DNA lesions that occur when proteins are covalently crosslinked to the DNA by the action of variety of agents like reactive oxygen species, aldehydes and metabolites, radiation, and chemotherapeutic drugs. Unrepaired DPCs are blockades to all DNA metabolic processes. Specifically, during DNA replication, replication forks stall at DPCs and are vulnerable to fork collapse, causing DNA breakage leading to genome instability and cancer. Replication-coupled DPC repair involves DPC degradation by proteases such as SPRTN or the proteasome and the subsequent removal of DNA-peptide adducts by nucleases and canonical DNA repair pathways. SPRTN is a DNA-dependent metalloprotease that cleaves DPC substrates in a sequence-independent manner and is also required for translesion DNA synthesis following DPC degradation. Biallelic mutations in SPRTN cause Ruijs-Aalfs (RJALS) syndrome, characterized by hepatocellular carcinoma and segmental progeria, indicating the critical role for SPRTN and DPC repair pathway in genome maintenance. In this review, we will discuss the mechanism of replication-coupled DPC repair, regulation of SPRTN function and its implications in human disease and cancer.
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Affiliation(s)
- Megan Perry
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, United States
| | - Gargi Ghosal
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, United States,Fred and Pamela Buffett Cancer Center, Omaha, NE, United States,*Correspondence: Gargi Ghosal,
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12
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Gupta P, Majumdar AG, Patro BS. Non-enzymatic function of WRN RECQL helicase regulates removal of topoisomerase-I-DNA covalent complexes and triggers NF-κB signaling in cancer. Aging Cell 2022; 21:e13625. [PMID: 35582959 PMCID: PMC9197415 DOI: 10.1111/acel.13625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 03/25/2022] [Accepted: 04/20/2022] [Indexed: 11/26/2022] Open
Abstract
Mutation in Werner (WRN) RECQL helicase is associated with premature aging syndrome (Werner syndrome, WS) and predisposition to multiple cancers. In patients with solid cancers, deficiency of the WRN RECQL helicase is paradoxically associated with enhanced overall survival in response to treatment with TOP1 inhibitors, which stabilize pathological TOP1‐DNA‐covalent‐complexes (TOP1cc) on the genome. However, the underlying mechanism of WRN in development of chemoresistance to TOP1 inhibitors is not yet explored. Our whole‐genome transcriptomic analysis for ~25,000 genes showed robust activation of NF‐κB‐dependent prosurvival genes in response to TOP1cc. CRISPR‐Cas9 knockout, shRNA silencing, and under‐expression of WRN confer high‐sensitivity of multiple cancers to TOP1 inhibitor. We demonstrated that WRN orchestrates TOP1cc repair through proteasome‐dependent and proteasome‐independent process, unleashing robust ssDNA generation. This in turn ensues signal transduction for CHK1 mediated NF‐κB‐activation through IκBα‐degradation and nuclear localization of p65 protein. Intriguingly, our site‐directed mutagenesis and rescue experiments revealed that neither RECQL‐helicase nor DNA‐exonuclease enzyme activity of WRN (WRNE84A, WRNK577M, and WRNE84A‐K577M) were required for TOP1cc removal, ssDNA generation and signaling for NF‐κB activation. In correlation with patient data and above results, the TOP1 inhibitor‐based targeted therapy showed that WRN‐deficient melanoma tumors were highly sensitive to TOP1 inhibition in preclinical in vivo mouse model. Collectively, our findings identify hitherto unknown non‐enzymatic role of WRN RECQL helicase in pathological mechanisms underlying TOP1cc processing and subsequent NF‐κB‐activation, offering a potential targeted therapy for WRN‐deficient cancer patients.
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Affiliation(s)
- Pooja Gupta
- Bio‐Organic Division Bhabha Atomic Research Centre Trombay Mumbai India
- Homi Bhabha National Institute Anushaktinagar Mumbai India
| | - Ananda Guha Majumdar
- Bio‐Organic Division Bhabha Atomic Research Centre Trombay Mumbai India
- Homi Bhabha National Institute Anushaktinagar Mumbai India
| | - Birija Sankar Patro
- Bio‐Organic Division Bhabha Atomic Research Centre Trombay Mumbai India
- Homi Bhabha National Institute Anushaktinagar Mumbai India
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13
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Crewe M, Madabhushi R. Topoisomerase-Mediated DNA Damage in Neurological Disorders. Front Aging Neurosci 2021; 13:751742. [PMID: 34899270 PMCID: PMC8656403 DOI: 10.3389/fnagi.2021.751742] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 10/23/2021] [Indexed: 12/12/2022] Open
Abstract
The nervous system is vulnerable to genomic instability and mutations in DNA damage response factors lead to numerous developmental and progressive neurological disorders. Despite this, the sources and mechanisms of DNA damage that are most relevant to the development of neuronal dysfunction are poorly understood. The identification of primarily neurological abnormalities in patients with mutations in TDP1 and TDP2 suggest that topoisomerase-mediated DNA damage could be an important underlying source of neuronal dysfunction. Here we review the potential sources of topoisomerase-induced DNA damage in neurons, describe the cellular mechanisms that have evolved to repair such damage, and discuss the importance of these repair mechanisms for preventing neurological disorders.
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Affiliation(s)
| | - Ram Madabhushi
- Departments of Psychiatry, Neuroscience, and Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, United States
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14
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Ashour ME, Mosammaparast N. Mechanisms of damage tolerance and repair during DNA replication. Nucleic Acids Res 2021; 49:3033-3047. [PMID: 33693881 PMCID: PMC8034635 DOI: 10.1093/nar/gkab101] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/28/2021] [Accepted: 03/02/2021] [Indexed: 01/05/2023] Open
Abstract
Accurate duplication of chromosomal DNA is essential for the transmission of genetic information. The DNA replication fork encounters template lesions, physical barriers, transcriptional machinery, and topological barriers that challenge the faithful completion of the replication process. The flexibility of replisomes coupled with tolerance and repair mechanisms counteract these replication fork obstacles. The cell possesses several universal mechanisms that may be activated in response to various replication fork impediments, but it has also evolved ways to counter specific obstacles. In this review, we will discuss these general and specific strategies to counteract different forms of replication associated damage to maintain genomic stability.
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Affiliation(s)
- Mohamed Elsaid Ashour
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
| | - Nima Mosammaparast
- Department of Pathology & Immunology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
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15
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Tsuda M, Kitamasu K, Kumagai C, Sugiyama K, Nakano T, Ide H. Tyrosyl-DNA phosphodiesterase 2 (TDP2) repairs topoisomerase 1 DNA-protein crosslinks and 3'-blocking lesions in the absence of tyrosyl-DNA phosphodiesterase 1 (TDP1). DNA Repair (Amst) 2020; 91-92:102849. [PMID: 32460231 DOI: 10.1016/j.dnarep.2020.102849] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/19/2020] [Accepted: 03/23/2020] [Indexed: 01/29/2023]
Abstract
Topoisomerase I (TOP1) resolves DNA topology during replication and transcription. The enzyme forms an intermediate TOP1 cleavage complex (TOP1cc) through transient TOP1-DNA-protein crosslinks. Camptothecin is a frontline anticancer agent that freezes this reaction intermediate, leading to the generation of irreversible TOP1ccs that act as 3'-blocking lesions. It is widely accepted that TOP1cc is repaired via a two-step pathway involving proteasomal degradation of TOP1cc to the crosslinked peptide, followed by removal of the TOP1cc-derived peptide from DNA by tyrosyl-DNA phosphodiesterase 1 (TDP1). In the present study, we developed an assay system to estimate repair kinetics of TOP1cc separately in the first and second steps, using monoclonal antibodies against the TOP1 protein and the TOP1 catalytic site peptide-DNA complex, respectively. Although TDP1-deficient (TDP1-/-) TK6 cells had normal kinetics of the first step, a delay in the kinetics of the second step was observed relative to that in wild-type cells. Tyrosyl-DNA phosphodiesterase 2 (TDP2) reportedly promotes the repair of TOP1-induced DNA damage in the absence of TDP1. The present assays additionally demonstrated that TDP2 promotes the second, but not the first, step of TOP1cc repair in the absence of TDP1. We also analyzed sensitivities of TK6 cells with deficiencies in TDP1 and/or TDP2 to agents that produce 3' -blocking lesions. These experiments showed that TDP1-/-TDP2-/- cells were more sensitive to the agents Azidothymidine (zidovudine), Cytarabine, Abacavir, Gemcitabine, and Trifluridine than TDP1-/- or TDP2-/- cells. Taken together, our findings confirm the roles of TDP2 in the repair of 3'-blocking lesions.
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Affiliation(s)
- Masataka Tsuda
- Program of Mathematical and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
| | - Kaito Kitamasu
- Program of Mathematical and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Chiho Kumagai
- Program of Mathematical and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Kazuya Sugiyama
- Program of Mathematical and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Toshiaki Nakano
- DNA Damage Chemistry Research Group, Institute for Quantum Life Science, National Institutes of Quantum and Radiological Science and Technology, 8-1-7 Umemidai, Kizugawa-shi, Kyoto 619-0215, Japan
| | - Hiroshi Ide
- Program of Mathematical and Life Sciences, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
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16
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Mei C, Lei L, Tan LM, Xu XJ, He BM, Luo C, Yin JY, Li X, Zhang W, Zhou HH, Liu ZQ. The role of single strand break repair pathways in cellular responses to camptothecin induced DNA damage. Biomed Pharmacother 2020; 125:109875. [DOI: 10.1016/j.biopha.2020.109875] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/24/2019] [Accepted: 01/06/2020] [Indexed: 12/12/2022] Open
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17
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Fielden J, Wiseman K, Torrecilla I, Li S, Hume S, Chiang SC, Ruggiano A, Narayan Singh A, Freire R, Hassanieh S, Domingo E, Vendrell I, Fischer R, Kessler BM, Maughan TS, El-Khamisy SF, Ramadan K. TEX264 coordinates p97- and SPRTN-mediated resolution of topoisomerase 1-DNA adducts. Nat Commun 2020; 11:1274. [PMID: 32152270 PMCID: PMC7062751 DOI: 10.1038/s41467-020-15000-w] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/16/2020] [Indexed: 12/03/2022] Open
Abstract
Eukaryotic topoisomerase 1 (TOP1) regulates DNA topology to ensure efficient DNA replication and transcription. TOP1 is also a major driver of endogenous genome instability, particularly when its catalytic intermediate-a covalent TOP1-DNA adduct known as a TOP1 cleavage complex (TOP1cc)-is stabilised. TOP1ccs are highly cytotoxic and a failure to resolve them underlies the pathology of neurological disorders but is also exploited in cancer therapy where TOP1ccs are the target of widely used frontline anti-cancer drugs. A critical enzyme for TOP1cc resolution is the tyrosyl-DNA phosphodiesterase (TDP1), which hydrolyses the bond that links a tyrosine in the active site of TOP1 to a 3' phosphate group on a single-stranded (ss)DNA break. However, TDP1 can only process small peptide fragments from ssDNA ends, raising the question of how the ~90 kDa TOP1 protein is processed upstream of TDP1. Here we find that TEX264 fulfils this role by forming a complex with the p97 ATPase and the SPRTN metalloprotease. We show that TEX264 recognises both unmodified and SUMO1-modifed TOP1 and initiates TOP1cc repair by recruiting p97 and SPRTN. TEX264 localises to the nuclear periphery, associates with DNA replication forks, and counteracts TOP1ccs during DNA replication. Altogether, our study elucidates the existence of a specialised repair complex required for upstream proteolysis of TOP1ccs and their subsequent resolution.
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Affiliation(s)
- John Fielden
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Katherine Wiseman
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Ignacio Torrecilla
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Shudong Li
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Samuel Hume
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Shih-Chieh Chiang
- The University of Sheffield Neuroscience Institute and the Healthy Lifespan Institute, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN, Sheffield, UK
| | - Annamaria Ruggiano
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Abhay Narayan Singh
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Raimundo Freire
- Unidad de Investigación, Hospital Universitario de Canarias, Ofra s/n, La Cuesta, 38320, La Laguna, Tenerife, Spain
- Instituto de Tecnologías Biomédicas, Universidad de La Laguna, 38200, La Laguna, Tenerife, Spain
- Universidad Fernando Pessoa Canarias, 35450, Las Palmas de Gran Canaria, Spain
| | - Sylvana Hassanieh
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Enric Domingo
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Iolanda Vendrell
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Roman Fischer
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Benedikt M Kessler
- TDI Mass Spectrometry Laboratory, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Timothy S Maughan
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
| | - Sherif F El-Khamisy
- The University of Sheffield Neuroscience Institute and the Healthy Lifespan Institute, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN, Sheffield, UK
| | - Kristijan Ramadan
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK.
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18
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Sun Y, Saha S, Wang W, Saha LK, Huang SYN, Pommier Y. Excision repair of topoisomerase DNA-protein crosslinks (TOP-DPC). DNA Repair (Amst) 2020; 89:102837. [PMID: 32200233 DOI: 10.1016/j.dnarep.2020.102837] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/22/2020] [Accepted: 02/25/2020] [Indexed: 12/13/2022]
Abstract
Topoisomerases are essential enzymes solving DNA topological problems such as supercoils, knots and catenanes that arise from replication, transcription, chromatin remodeling and other nucleic acid metabolic processes. They are also the targets of widely used anticancer drugs (e.g. topotecan, irinotecan, enhertu, etoposide, doxorubicin, mitoxantrone) and fluoroquinolone antibiotics (e.g. ciprofloxacin and levofloxacin). Topoisomerases manipulate DNA topology by cleaving one DNA strand (TOP1 and TOP3 enzymes) or both in concert (TOP2 enzymes) through the formation of transient enzyme-DNA cleavage complexes (TOPcc) with phosphotyrosyl linkages between DNA ends and the catalytic tyrosyl residue of the enzymes. Failure in the self-resealing of TOPcc results in persistent TOPcc (which we refer it to as topoisomerase DNA-protein crosslinks (TOP-DPC)) that threaten genome integrity and lead to cancers and neurodegenerative diseases. The cell prevents the accumulation of topoisomerase-mediated DNA damage by excising TOP-DPC and ligating the associated breaks using multiple pathways conserved in eukaryotes. Tyrosyl-DNA phosphodiesterases (TDP1 and TDP2) cleave the tyrosyl-DNA bonds whereas structure-specific endonucleases such as Mre11 and XPF (Rad1) incise the DNA phosphodiester backbone to remove the TOP-DPC along with the adjacent DNA segment. The proteasome and metalloproteases of the WSS1/Spartan family typify proteolytic repair pathways that debulk TOP-DPC to make the peptide-DNA bonds accessible to the TDPs and endonucleases. The purpose of this review is to summarize our current understanding of how the cell excises TOP-DPC and why, when and where the cell recruits one specific mechanism for repairing topoisomerase-mediated DNA damage, acquiring resistance to therapeutic topoisomerase inhibitors and avoiding genomic instability, cancers and neurodegenerative diseases.
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Affiliation(s)
- Yilun Sun
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Sourav Saha
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Wenjie Wang
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Liton Kumar Saha
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Shar-Yin Naomi Huang
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Yves Pommier
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States.
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19
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Sutcu HH, Matta E, Ishchenko AA. Role of PARP-catalyzed ADP-ribosylation in the Crosstalk Between DNA Strand Breaks and Epigenetic Regulation. J Mol Biol 2019:S0022-2836(19)30719-3. [PMID: 31866292 DOI: 10.1016/j.jmb.2019.12.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/29/2019] [Accepted: 12/05/2019] [Indexed: 12/12/2022]
Abstract
Covalent linkage of ADP-ribose units to proteins catalyzed by poly(ADP-ribose) polymerases (PARPs) plays important signaling functions in a plethora of cellular processes including DNA damage response, chromatin organization, and gene transcription. Poly- and mono-ADP-ribosylation of target macromolecules are often responsible both for the initiation and for coordination of these processes in mammalian cells. Currently, the number of cellular targets for ADP-ribosylation is rapidly expanding, and the molecular mechanisms underlying the broad substrate specificity of PARPs present enormous interest. In this review, the roles of PARP-mediated modifications of protein and nucleic acids, the readers of ADP-ribosylated structures, and the origin and function of programmed DNA strand breaks in PARP activation, transcription regulation, and DNA demethylation are discussed.
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Affiliation(s)
- Haser H Sutcu
- Groupe «Réparation de l'ADN», Equipe Labellisée par la Ligue Nationale contre le Cancer, CNRS UMR 8200, Univ. Paris-Sud, Université Paris-Saclay, Villejuif, F-94805, France; Gustave Roussy, Université Paris-Saclay, Villejuif, F-94805, France
| | - Elie Matta
- Groupe «Réparation de l'ADN», Equipe Labellisée par la Ligue Nationale contre le Cancer, CNRS UMR 8200, Univ. Paris-Sud, Université Paris-Saclay, Villejuif, F-94805, France; Gustave Roussy, Université Paris-Saclay, Villejuif, F-94805, France
| | - Alexander A Ishchenko
- Groupe «Réparation de l'ADN», Equipe Labellisée par la Ligue Nationale contre le Cancer, CNRS UMR 8200, Univ. Paris-Sud, Université Paris-Saclay, Villejuif, F-94805, France; Gustave Roussy, Université Paris-Saclay, Villejuif, F-94805, France.
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20
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Lountos GT, Zhao XZ, Kiselev E, Tropea JE, Needle D, Pommier Y, Burke TR, Waugh DS. Identification of a ligand binding hot spot and structural motifs replicating aspects of tyrosyl-DNA phosphodiesterase I (TDP1) phosphoryl recognition by crystallographic fragment cocktail screening. Nucleic Acids Res 2019; 47:10134-10150. [PMID: 31199869 DOI: 10.1093/nar/gkz515] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 05/20/2019] [Accepted: 06/11/2019] [Indexed: 02/02/2023] Open
Abstract
Tyrosyl DNA-phosphodiesterase I (TDP1) repairs type IB topoisomerase (TOP1) cleavage complexes generated by TOP1 inhibitors commonly used as anticancer agents. TDP1 also removes DNA 3' end blocking lesions generated by chain-terminating nucleosides and alkylating agents, and base oxidation both in the nuclear and mitochondrial genomes. Combination therapy with TDP1 inhibitors is proposed to synergize with topoisomerase targeting drugs to enhance selectivity against cancer cells exhibiting deficiencies in parallel DNA repair pathways. A crystallographic fragment screening campaign against the catalytic domain of TDP1 was conducted to identify new lead compounds. Crystal structures revealed two fragments that bind to the TDP1 active site and exhibit inhibitory activity against TDP1. These fragments occupy a similar position in the TDP1 active site as seen in prior crystal structures of TDP1 with bound vanadate, a transition state mimic. Using structural insights into fragment binding, several fragment derivatives have been prepared and evaluated in biochemical assays. These results demonstrate that fragment-based methods can be a highly feasible approach toward the discovery of small-molecule chemical scaffolds to target TDP1, and for the first time, we provide co-crystal structures of small molecule inhibitors bound to TDP1, which could serve for the rational development of medicinal TDP1 inhibitors.
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Affiliation(s)
- George T Lountos
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Xue Zhi Zhao
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Evgeny Kiselev
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Joseph E Tropea
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Danielle Needle
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Yves Pommier
- Developmental Therapeutics Branch & Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Terrence R Burke
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - David S Waugh
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
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21
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Cassani C, Gobbini E, Vertemara J, Wang W, Marsella A, Sung P, Tisi R, Zampella G, Longhese MP. Structurally distinct Mre11 domains mediate MRX functions in resection, end-tethering and DNA damage resistance. Nucleic Acids Res 2019; 46:2990-3008. [PMID: 29420790 PMCID: PMC5888019 DOI: 10.1093/nar/gky086] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/31/2018] [Indexed: 11/27/2022] Open
Abstract
Sae2 cooperates with the Mre11–Rad50-Xrs2 (MRX) complex to initiate resection of DNA double-strand breaks (DSBs) and to maintain the DSB ends in close proximity to allow their repair. How these diverse MRX-Sae2 functions contribute to DNA damage resistance is not known. Here, we describe mre11 alleles that suppress the hypersensitivity of sae2Δ cells to genotoxic agents. By assessing the impact of these mutations at the cellular and structural levels, we found that all the mre11 alleles that restore sae2Δ resistance to both camptothecin and phleomycin affect the Mre11 N-terminus and suppress the resection defect of sae2Δ cells by lowering MRX and Tel1 association to DSBs. As a consequence, the diminished Tel1 persistence potentiates Sgs1-Dna2 resection activity by decreasing Rad9 association to DSBs. By contrast, the mre11 mutations restoring sae2Δ resistance only to phleomycin are located in Mre11 C-terminus and bypass Sae2 function in end-tethering but not in DSB resection, possibly by destabilizing the Mre11–Rad50 open conformation. These findings unmask the existence of structurally distinct Mre11 domains that support resistance to genotoxic agents by mediating different processes.
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Affiliation(s)
- Corinne Cassani
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milano, Italy
| | - Elisa Gobbini
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milano, Italy
| | - Jacopo Vertemara
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milano, Italy
| | - Weibin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Antonio Marsella
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milano, Italy
| | - Patrick Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Renata Tisi
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milano, Italy
| | - Giuseppe Zampella
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milano, Italy
| | - Maria Pia Longhese
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milano, Italy
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22
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Nitiss KC, Nitiss JL, Hanakahi LA. DNA Damage by an essential enzyme: A delicate balance act on the tightrope. DNA Repair (Amst) 2019; 82:102639. [PMID: 31437813 DOI: 10.1016/j.dnarep.2019.102639] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 06/18/2019] [Accepted: 07/01/2019] [Indexed: 01/07/2023]
Abstract
DNA topoisomerases are essential for DNA metabolic processes such as replication and transcription. Since DNA is double stranded, the unwinding needed for these processes results in DNA supercoiling and catenation of replicated molecules. Changing the topology of DNA molecules to relieve supercoiling or resolve catenanes requires that DNA be transiently cut. While topoisomerases carry out these processes in ways that minimize the likelihood of genome instability, there are several ways that topoisomerases may fail. Topoisomerases can be induced to fail by therapeutic small molecules such as by fluoroquinolones that target bacterial topoisomerases, or a variety of anti-cancer agents that target the eukaryotic enzymes. Increasingly, there have been a large number of agents and processes, including natural products and their metabolites, DNA damage, and the intrinsic properties of the enzymes that can lead to long-lasting DNA breaks that subsequently lead to genome instability, cancer, and other diseases. Understanding the processes that can interfere with topoisomerases and how cells respond when topoisomerases fail will be important in minimizing the consequences when enzymes need to transiently interfere with DNA integrity.
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Affiliation(s)
- Karin C Nitiss
- University of Illinois College of Medicine, Department of Biomedical Sciences, Rockford, IL, 61107, United States; University of Illinois College of Pharmacy, Biopharmaceutical Sciences Department, Rockford IL, 61107, United States
| | - John L Nitiss
- University of Illinois College of Pharmacy, Biopharmaceutical Sciences Department, Rockford IL, 61107, United States.
| | - Leslyn A Hanakahi
- University of Illinois College of Pharmacy, Biopharmaceutical Sciences Department, Rockford IL, 61107, United States.
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23
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Thomas A, Pommier Y. Targeting Topoisomerase I in the Era of Precision Medicine. Clin Cancer Res 2019; 25:6581-6589. [PMID: 31227499 DOI: 10.1158/1078-0432.ccr-19-1089] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 05/06/2019] [Accepted: 06/17/2019] [Indexed: 12/24/2022]
Abstract
Irinotecan and topotecan have been widely used as anticancer drugs for the past 20 years. Because of their selectivity as topoisomerase I (TOP1) inhibitors that trap TOP1 cleavage complexes, camptothecins are also widely used to elucidate the DNA repair pathways associated with DNA-protein cross-links and replication stress. This review summarizes the basic molecular mechanisms of action of TOP1 inhibitors, their current use, and limitations as anticancer agents. We introduce new therapeutic strategies based on novel TOP1 inhibitor chemical scaffolds including the indenoisoquinolines LMP400 (indotecan), LMP776 (indimitecan), and LMP744, and on tumor-targeted delivery TOP1 inhibitors using liposome, PEGylation, and antibody-drug conjugates. We also address how tumor-specific determinants such as homologous recombination defects (HRD and BRCAness) and Schlafen 11 (SLFN11) expression can be used to guide clinical application of TOP1 inhibitors in combination with DNA damage response inhibitors including PARP, ATR, CHEK1, and ATM inhibitors.
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Affiliation(s)
- Anish Thomas
- Developmental Therapeutics Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland.
| | - Yves Pommier
- Developmental Therapeutics Branch, Center for Cancer Research, NCI, NIH, Bethesda, Maryland.
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Kawale AS, Akopiants K, Valerie K, Ruis B, Hendrickson EA, Huang SYN, Pommier Y, Povirk LF. TDP1 suppresses mis-joining of radiomimetic DNA double-strand breaks and cooperates with Artemis to promote optimal nonhomologous end joining. Nucleic Acids Res 2018; 46:8926-8939. [PMID: 30113698 PMCID: PMC6158748 DOI: 10.1093/nar/gky694] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 07/18/2018] [Accepted: 07/29/2018] [Indexed: 01/04/2023] Open
Abstract
The Artemis nuclease and tyrosyl-DNA phosphodiesterase (TDP1) are each capable of resolving protruding 3'-phosphoglycolate (PG) termini of DNA double-strand breaks (DSBs). Consequently, both a knockout of Artemis and a knockout/knockdown of TDP1 rendered cells sensitive to the radiomimetic agent neocarzinostatin (NCS), which induces 3'-PG-terminated DSBs. Unexpectedly, however, a knockdown or knockout of TDP1 in Artemis-null cells did not confer any greater sensitivity than either deficiency alone, indicating a strict epistasis between TDP1 and Artemis. Moreover, a deficiency in Artemis, but not TDP1, resulted in a fraction of unrepaired DSBs, which were assessed as 53BP1 foci. Conversely, a deficiency in TDP1, but not Artemis, resulted in a dramatic increase in dicentric chromosomes following NCS treatment. An inhibitor of DNA-dependent protein kinase, a key regulator of the classical nonhomologous end joining (C-NHEJ) pathway sensitized cells to NCS, but eliminated the sensitizing effects of both TDP1 and Artemis deficiencies. These results suggest that TDP1 and Artemis perform different functions in the repair of terminally blocked DSBs by the C-NHEJ pathway, and that whereas an Artemis deficiency prevents end joining of some DSBs, a TDP1 deficiency tends to promote DSB mis-joining.
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Affiliation(s)
- Ajinkya S Kawale
- Department of Pharmacology and Toxicology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Konstantin Akopiants
- Department of Pharmacology and Toxicology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Kristoffer Valerie
- Department of Radiation Oncology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Brian Ruis
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Eric A Hendrickson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Shar-yin N Huang
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 5068, Bethesda, MD 20892-4255, USA
| | - Yves Pommier
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 5068, Bethesda, MD 20892-4255, USA
| | - Lawrence F Povirk
- Department of Pharmacology and Toxicology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
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Chalasani SL, Kawale AS, Akopiants K, Yu Y, Fanta M, Weinfeld M, Povirk LF. Persistent 3'-phosphate termini and increased cytotoxicity of radiomimetic DNA double-strand breaks in cells lacking polynucleotide kinase/phosphatase despite presence of an alternative 3'-phosphatase. DNA Repair (Amst) 2018; 68:12-24. [PMID: 29807321 DOI: 10.1016/j.dnarep.2018.05.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 05/07/2018] [Indexed: 02/08/2023]
Abstract
Polynucleotide kinase/phosphatase (PNKP) has been implicated in non-homologous end joining (NHEJ) of DNA double-strand breaks (DSBs). To assess the consequences of PNKP deficiency for NHEJ of 3'-phosphate-ended DSBs, PNKP-deficient derivatives of HCT116 and of HeLa cells were generated using CRISPR/CAS9. For both cell lines, PNKP deficiency conferred sensitivity to ionizing radiation as well as to neocarzinostatin (NCS), which specifically induces DSBs bearing protruding 3'-phosphate termini. Moreover, NCS-induced DSBs, detected as 53BP1 foci, were more persistent in PNKP -/- HCT116 cells compared to their wild-type (WT) counterparts. Surprisingly, PNKP-deficient whole-cell and nuclear extracts were biochemically competent in removing both protruding and recessed 3'-phosphates from synthetic DSB substrates, albeit much less efficiently than WT extracts, suggesting an alternative 3'-phosphatase. Measurements by ligation-mediated PCR showed that PNKP-deficient HeLa cells contained significantly more 3'-phosphate-terminated and fewer 3'-hydroxyl-terminated DSBs than parental cells 5-15 min after NCS treatment, but this difference disappeared by 1 h. These results suggest that, despite presence of an alternative 3'-phosphatase, loss of PNKP significantly sensitizes cells to 3'-phosphate-terminated DSBs, due to a 3'-dephosphorylation defect.
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Affiliation(s)
- Sri Lakshmi Chalasani
- Department of Pharmacology and Toxicology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, United States
| | - Ajinkya S Kawale
- Department of Pharmacology and Toxicology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, United States
| | - Konstantin Akopiants
- Department of Pharmacology and Toxicology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, United States
| | - Yaping Yu
- Centre for Genome Engineering, University of Calgary, Calgary, AB, Canada
| | - Mesfin Fanta
- Department of Oncology, Cross Cancer Institute and University of Alberta, Edmonton, AB, Canada
| | - Michael Weinfeld
- Department of Oncology, Cross Cancer Institute and University of Alberta, Edmonton, AB, Canada
| | - Lawrence F Povirk
- Department of Pharmacology and Toxicology and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, United States.
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Abstract
Covalent DNA-protein crosslinks (DPCs, also known as protein adducts) of topoisomerases and other proteins with DNA are highly toxic DNA lesions. Of note, chemical agents that induce DPCs include widely used classes of chemotherapeutics. Their bulkiness blocks virtually every chromatin-based process and makes them intractable for repair by canonical repair pathways. Distinct DPC repair pathways employ unique points of attack and are crucial for the maintenance of genome stability. Tyrosyl-DNA phosphodiesterases (TDPs) directly hydrolyse the covalent linkage between protein and DNA. The MRE11-RAD50-NBS1 (MRN) nuclease complex targets the DNA component of DPCs, excising the fragment affected by the lesion, whereas proteases of the spartan (SPRTN)/weak suppressor of SMT3 protein 1 (Wss1) family target the protein component. Loss of these pathways renders cells sensitive to DPC-inducing chemotherapeutics, and DPC repair pathways are thus attractive targets for combination cancer therapy.
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Affiliation(s)
- Julian Stingele
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | | | - Simon J Boulton
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
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Physiological functions of programmed DNA breaks in signal-induced transcription. Nat Rev Mol Cell Biol 2017; 18:471-476. [PMID: 28537575 DOI: 10.1038/nrm.2017.43] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The idea that signal-dependent transcription might involve the generation of transient DNA nicks or even breaks in the regulatory regions of genes, accompanied by activation of DNA damage repair pathways, would seem to be counterintuitive, as DNA damage is usually considered harmful to cellular integrity. However, recent studies have generated a substantial body of evidence that now argues that programmed DNA single- or double-strand breaks can, at least in specific cases, have a role in transcription regulation. Here, we discuss the emerging functions of DNA breaks in the relief of DNA torsional stress and in promoter and enhancer activation.
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Pommier Y, Sun Y, Huang SYN, Nitiss JL. Roles of eukaryotic topoisomerases in transcription, replication and genomic stability. Nat Rev Mol Cell Biol 2016; 17:703-721. [DOI: 10.1038/nrm.2016.111] [Citation(s) in RCA: 540] [Impact Index Per Article: 67.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Seifert FU, Lammens K, Stoehr G, Kessler B, Hopfner KP. Structural mechanism of ATP-dependent DNA binding and DNA end bridging by eukaryotic Rad50. EMBO J 2016; 35:759-72. [PMID: 26896444 DOI: 10.15252/embj.201592934] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/13/2016] [Indexed: 01/08/2023] Open
Abstract
The Mre11-Rad50-Nbs1 (MRN) complex is a central factor in the repair of DNA double-strand breaks (DSBs). The ATP-dependent mechanisms of how MRN detects and endonucleolytically processes DNA ends for the repair by microhomology-mediated end-joining or further resection in homologous recombination are still unclear. Here, we report the crystal structures of the ATPγS-bound dimer of the Rad50(NBD)(nucleotide-binding domain) from the thermophilic eukaryote Chaetomium thermophilum(Ct) in complex with either DNA or CtMre11(RBD)(Rad50-binding domain) along with small-angle X-ray scattering and cross-linking studies. The structure and DNA binding motifs were validated by DNA binding experiments in vitro and mutational analyses in Saccharomyces cerevisiae in vivo Our analyses provide a structural framework for the architecture of the eukaryotic Mre11-Rad50 complex. They show that a Rad50 dimer binds approximately 18 base pairs of DNA along the dimer interface in anATP-dependent fashion or bridges two DNA ends with a preference for 3' overhangs. Finally, our results may provide a general framework for the interaction of ABC ATPase domains of the Rad50/SMC/RecN protein family with DNA.
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Affiliation(s)
- Florian Ulrich Seifert
- Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, Munich, Germany
| | - Katja Lammens
- Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, Munich, Germany
| | - Gabriele Stoehr
- Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, Munich, Germany
| | - Brigitte Kessler
- Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, Munich, Germany
| | - Karl-Peter Hopfner
- Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, Munich, Germany Center for Integrated Protein Sciences, Munich, Germany
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Xu Y, Her C. Inhibition of Topoisomerase (DNA) I (TOP1): DNA Damage Repair and Anticancer Therapy. Biomolecules 2015; 5:1652-70. [PMID: 26287259 PMCID: PMC4598769 DOI: 10.3390/biom5031652] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 07/14/2015] [Indexed: 12/31/2022] Open
Abstract
Most chemotherapy regimens contain at least one DNA-damaging agent that preferentially affects the growth of cancer cells. This strategy takes advantage of the differences in cell proliferation between normal and cancer cells. Chemotherapeutic drugs are usually designed to target rapid-dividing cells because sustained proliferation is a common feature of cancer [1,2]. Rapid DNA replication is essential for highly proliferative cells, thus blocking of DNA replication will create numerous mutations and/or chromosome rearrangements—ultimately triggering cell death [3]. Along these lines, DNA topoisomerase inhibitors are of great interest because they help to maintain strand breaks generated by topoisomerases during replication. In this article, we discuss the characteristics of topoisomerase (DNA) I (TOP1) and its inhibitors, as well as the underlying DNA repair pathways and the use of TOP1 inhibitors in cancer therapy.
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Affiliation(s)
- Yang Xu
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Mail Drop 64-7520, Pullman, WA 99164, USA.
| | - Chengtao Her
- School of Molecular Biosciences, College of Veterinary Medicine, Washington State University, Mail Drop 64-7520, Pullman, WA 99164, USA.
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Takahata C, Masuda Y, Takedachi A, Tanaka K, Iwai S, Kuraoka I. Repair synthesis step involving ERCC1-XPF participates in DNA repair of the Top1-DNA damage complex. Carcinogenesis 2015; 36:841-51. [DOI: 10.1093/carcin/bgv078] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 05/22/2015] [Indexed: 11/13/2022] Open
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Puc J, Kozbial P, Li W, Tan Y, Liu Z, Suter T, Ohgi KA, Zhang J, Aggarwal AK, Rosenfeld MG. Ligand-dependent enhancer activation regulated by topoisomerase-I activity. Cell 2015; 160:367-80. [PMID: 25619691 DOI: 10.1016/j.cell.2014.12.023] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 10/28/2014] [Accepted: 12/10/2014] [Indexed: 10/24/2022]
Abstract
The discovery that enhancers are regulated transcription units, encoding eRNAs, has raised new questions about the mechanisms of their activation. Here, we report an unexpected molecular mechanism that underlies ligand-dependent enhancer activation, based on DNA nicking to relieve torsional stress from eRNA synthesis. Using dihydrotestosterone (DHT)-induced binding of androgen receptor (AR) to prostate cancer cell enhancers as a model, we show rapid recruitment, within minutes, of DNA topoisomerase I (TOP1) to a large cohort of AR-regulated enhancers. Furthermore, we show that the DNA nicking activity of TOP1 is a prerequisite for robust eRNA synthesis and enhancer activation and is kinetically accompanied by the recruitment of ATR and the MRN complex, followed by additional components of DNA damage repair machinery to the AR-regulated enhancers. Together, our studies reveal a linkage between eRNA synthesis and ligand-dependent TOP1-mediated nicking-a strategy exerting quantitative effects on eRNA expression in regulating AR-bound enhancer-dependent transcriptional programs.
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Affiliation(s)
- Janusz Puc
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0648, USA
| | - Piotr Kozbial
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0648, USA
| | - Wenbo Li
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0648, USA
| | - Yuliang Tan
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0648, USA
| | - Zhijie Liu
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0648, USA
| | - Tom Suter
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0648, USA; Division of Biological Sciences, Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093-0648, USA
| | - Kenneth A Ohgi
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0648, USA
| | - Jie Zhang
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0648, USA
| | - Aneel K Aggarwal
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Michael G Rosenfeld
- Howard Hughes Medical Institute, Department of Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0648, USA.
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Hopfner KP. ATP puts the brake on DNA double-strand break repair: a new study shows that ATP switches the Mre11-Rad50-Nbs1 repair factor between signaling and processing of DNA ends. Bioessays 2014; 36:1170-8. [PMID: 25213441 DOI: 10.1002/bies.201400102] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
DNA double-strand breaks (DSBs) are one of the most deleterious forms of DNA damage and can result in cell inviability or chromosomal aberrations. The Mre11-Rad50-Nbs1 (MRN) ATPase-nuclease complex is a central player in the cellular response to DSBs and is implicated in the sensing and nucleolytic processing of DSBs, as well as in DSB signaling by activating the cell cycle checkpoint kinase ATM. ATP binding to Rad50 switches MRN from an open state with exposed Mre11 nuclease sites to a closed state with partially buried nuclease sites. The functional meaning of this switch remained unclear. A new study shows that ATP binding to Rad50 promotes DSB recognition, tethering, and ATM activation, while ATP hydrolysis opens the nuclease active sites to promote processing of DSBs. MRN thus emerges as functional switch that may coordinate the temporal transition from signaling to processing of DSBs.
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Affiliation(s)
- Karl-Peter Hopfner
- Department of Biochemistry, Gene Center, Ludwig-Maximilians-University, Munich, Germany; Center for Integrated Protein Science Munich, Gene Center, Ludwig-Maximilians-University, Munich, Germany
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Neuroprotection and repair of 3'-blocking DNA ends by glaikit (gkt) encoding Drosophila tyrosyl-DNA phosphodiesterase 1 (TDP1). Proc Natl Acad Sci U S A 2014; 111:15816-20. [PMID: 25331878 DOI: 10.1073/pnas.1415011111] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Tyrosyl-DNA phosphodiesterase (TDP1) is a phylogenetically conserved enzyme critical for the removal of blocking lesions at the 3' ends of DNA or RNA. This study analyzes the Drosophila TDP1 gene ortholog glaikit (gkt) and its possible role(s) in the repair of endogenous DNA lesions and neuroprotection. To do so, we studied a homozygous PiggyBac insertion (c03958) that disrupts the 5' UTR of gkt. Protein extracts of c03958 flies were defective in hydrolyzing 3'-DNA-tyrosyl residues, demonstrating that gkt is the Drosophila TDP1. Although the mutant is generally healthy and fertile, females exhibit reduced lifespan and diminished climbing ability. This phenotype was rescued by neuronal expression of TDP1. In addition, when c03958 larvae were exposed to bleomycin, an agent that produces oxidative DNA damage, or topoisomerase I-targeted drugs (camptothecin and a noncamptothecin indenoisoquinoline derivative, LMP-776), survivors displayed rough eye patches, which were rescued by neuronal expression of TDP1. Our study establishes that gkt is the Drosophila TDP1 gene, and that it is critical for neuroprotection, normal longevity, and repair of damaged DNA.
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Pavelitz T, Renfro L, Foster NR, Caracol A, Welsch P, Lao VV, Grady WB, Niedzwiecki D, Saltz LB, Bertagnolli MM, Goldberg RM, Rabinovitch PS, Emond M, Monnat RJ, Maizels N. MRE11-deficiency associated with improved long-term disease free survival and overall survival in a subset of stage III colon cancer patients in randomized CALGB 89803 trial. PLoS One 2014; 9:e108483. [PMID: 25310185 PMCID: PMC4195600 DOI: 10.1371/journal.pone.0108483] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 08/19/2014] [Indexed: 11/19/2022] Open
Abstract
Purpose Colon cancers deficient in mismatch repair (MMR) may exhibit diminished expression of the DNA repair gene, MRE11, as a consequence of contraction of a T11 mononucleotide tract. This study investigated MRE11 status and its association with prognosis, survival and drug response in patients with stage III colon cancer. Patients and Methods Cancer and Leukemia Group B 89803 (Alliance) randomly assigned 1,264 patients with stage III colon cancer to postoperative weekly adjuvant bolus 5-fluorouracil/leucovorin (FU/LV) or irinotecan+FU/LV (IFL), with 8 year follow-up. Tumors from these patients were analyzed to determine stability of a T11 tract in the MRE11 gene. The primary endpoint was overall survival (OS), and a secondary endpoint was disease-free survival (DFS). Non-proportional hazards were addressed using time-dependent covariates in Cox analyses. Results Of 625 tumor cases examined, 70 (11.2%) exhibited contraction at the T11 tract in one or both MRE11 alleles and were thus predicted to be deficient in MRE11 (dMRE11). In pooled treatment analyses, dMRE11 patients showed initially reduced DFS and OS but improved long-term DFS and OS compared with patients with an intact MRE11 T11 tract. In the subgroup of dMRE11 patients treated with IFL, an unexplained early increase in mortality but better long-term DFS than IFL-treated pMRE11 patients was observed. Conclusions Analysis of this relatively small number of patients and events showed that the dMRE11 marker predicts better prognosis independent of treatment in the long-term. In subgroup analyses, dMRE11 patients treated with irinotecan exhibited unexplained short-term mortality. MRE11 status is readily assayed and may therefore prove to be a useful prognostic marker, provided that the results reported here for a relatively small number of patients can be generalized in independent analyses of larger numbers of samples. Trial Registration ClinicalTrials.gov NCT00003835
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Affiliation(s)
- Thomas Pavelitz
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Lindsay Renfro
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Nathan R. Foster
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Amber Caracol
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington, United States of America
| | - Piri Welsch
- Department of Genome Sciences, University of Washington Medical School, Seattle, Washington, United States of America
| | - Victoria Valinluck Lao
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Surgery, University of Washington Medical School, Seattle, Washington, United States of America
| | - William B. Grady
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Medicine, University of Washington Medical School, Seattle, Washington, United States of America
| | - Donna Niedzwiecki
- Cancer and Leukemia Group B Statistical Center, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Leonard B. Saltz
- Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Monica M. Bertagnolli
- Dana-Farber Cancer Institute and Brigham and Women’s Hospital, Boston, Massachusetts, United States of America
| | | | - Peter S. Rabinovitch
- Department of Pathology, University of Washington Medical School, Seattle, Washington, United States of America
| | - Mary Emond
- Department of Biostatistics, University of Washington, Seattle, Washington, United States of America
| | - Raymond J. Monnat
- Department of Genome Sciences, University of Washington Medical School, Seattle, Washington, United States of America
- Department of Pathology, University of Washington Medical School, Seattle, Washington, United States of America
| | - Nancy Maizels
- Department of Immunology, University of Washington, Seattle, Washington, United States of America
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, Washington, United States of America
- Department of Pathology, University of Washington Medical School, Seattle, Washington, United States of America
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Abstract
TDP1 and TDP2 were discovered and named based on the fact they process 3'- and 5'-DNA ends by excising irreversible protein tyrosyl-DNA complexes involving topoisomerases I and II, respectively. Yet, both enzymes have an extended spectrum of activities. TDP1 not only excises trapped topoisomerases I (Top1 in the nucleus and Top1mt in mitochondria), but also repairs oxidative damage-induced 3'-phosphoglycolates and alkylation damage-induced DNA breaks, and excises chain terminating anticancer and antiviral nucleosides in the nucleus and mitochondria. The repair function of TDP2 is devoted to the excision of topoisomerase II- and potentially topoisomerases III-DNA adducts. TDP2 is also essential for the life cycle of picornaviruses (important human and bovine pathogens) as it unlinks VPg proteins from the 5'-end of the viral RNA genome. Moreover, TDP2 has been involved in signal transduction (under the former names of TTRAP or EAPII). The DNA repair partners of TDP1 include PARP1, XRCC1, ligase III and PNKP from the base excision repair (BER) pathway. By contrast, TDP2 repair functions are coordinated with Ku and ligase IV in the non-homologous end joining pathway (NHEJ). This article summarizes and compares the biochemistry, functions, and post-translational regulation of TDP1 and TDP2, as well as the relevance of TDP1 and TDP2 as determinants of response to anticancer agents. We discuss the rationale for developing TDP inhibitors for combinations with topoisomerase inhibitors (topotecan, irinotecan, doxorubicin, etoposide, mitoxantrone) and DNA damaging agents (temozolomide, bleomycin, cytarabine, and ionizing radiation), and as novel antiviral agents.
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Affiliation(s)
- Yves Pommier
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Building 37, Room 5068, NIH, Bethesda, MD 20892, USA.
| | - Shar-yin N Huang
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Building 37, Room 5068, NIH, Bethesda, MD 20892, USA
| | - Rui Gao
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Building 37, Room 5068, NIH, Bethesda, MD 20892, USA
| | - Benu Brata Das
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Building 37, Room 5068, NIH, Bethesda, MD 20892, USA; Laboratory of Molecular Biology, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Junko Murai
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Building 37, Room 5068, NIH, Bethesda, MD 20892, USA; Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku 606-8501, Japan
| | - Christophe Marchand
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Building 37, Room 5068, NIH, Bethesda, MD 20892, USA
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Kiianitsa K, Maizels N. Ultrasensitive isolation, identification and quantification of DNA-protein adducts by ELISA-based RADAR assay. Nucleic Acids Res 2014; 42:e108. [PMID: 24914050 PMCID: PMC4117749 DOI: 10.1093/nar/gku490] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Enzymes that form transient DNA-protein covalent complexes are targets for several potent classes of drugs used to treat infectious disease and cancer, making it important to establish robust and rapid procedures for analysis of these complexes. We report a method for isolation of DNA-protein adducts and their identification and quantification, using techniques compatible with high-throughput screening. This method is based on the RADAR assay for DNA adducts that we previously developed (Kiianitsa and Maizels (2013) A rapid and sensitive assay for DNA-protein covalent complexes in living cells. Nucleic Acids Res., 41:e104), but incorporates three key new steps of broad applicability. (i) Silica-assisted ethanol/isopropanol precipitation ensures reproducible and efficient recovery of DNA and DNA-protein adducts at low centrifugal forces, enabling cell culture and DNA precipitation to be carried out in a single microtiter plate. (ii) Rigorous purification of DNA-protein adducts by a procedure that eliminates free proteins and free nucleic acids, generating samples suitable for detection of novel protein adducts (e.g. by mass spectroscopy). (iii) Identification and quantification of DNA-protein adducts by direct ELISA assay. The ELISA-based RADAR assay can detect Top1-DNA and Top2a-DNA adducts in human cells, and gyrase-DNA adducts in Escherichia coli. This approach will be useful for discovery and characterization of new drugs to treat infectious disease and cancer, and for development of companion diagnostics assays for individualized medicine.
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Affiliation(s)
| | - Nancy Maizels
- Department of Immunology, University of Washington, Seattle, WA 98195, USA Department of Biochemistry, University of Washington, Seattle, WA 98195, USA Department of Pathology, University of Washington, Seattle, WA 98195, USA
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Das BB, Huang SYN, Murai J, Rehman I, Amé JC, Sengupta S, Das SK, Majumdar P, Zhang H, Biard D, Majumder HK, Schreiber V, Pommier Y. PARP1-TDP1 coupling for the repair of topoisomerase I-induced DNA damage. Nucleic Acids Res 2014; 42:4435-49. [PMID: 24493735 PMCID: PMC3985661 DOI: 10.1093/nar/gku088] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Poly(ADP-ribose) polymerases (PARP) attach poly(ADP-ribose) (PAR) chains to various proteins including themselves and chromatin. Topoisomerase I (Top1) regulates DNA supercoiling and is the target of camptothecin and indenoisoquinoline anticancer drugs, as it forms Top1 cleavage complexes (Top1cc) that are trapped by the drugs. Endogenous and carcinogenic DNA lesions can also trap Top1cc. Tyrosyl-DNA phosphodiesterase 1 (TDP1), a key repair enzyme for trapped Top1cc, hydrolyzes the phosphodiester bond between the DNA 3'-end and the Top1 tyrosyl moiety. Alternative repair pathways for Top1cc involve endonuclease cleavage. However, it is unknown what determines the choice between TDP1 and the endonuclease repair pathways. Here we show that PARP1 plays a critical role in this process. By generating TDP1 and PARP1 double-knockout lymphoma chicken DT40 cells, we demonstrate that TDP1 and PARP1 are epistatic for the repair of Top1cc. The N-terminal domain of TDP1 directly binds the C-terminal domain of PARP1, and TDP1 is PARylated by PARP1. PARylation stabilizes TDP1 together with SUMOylation of TDP1. TDP1 PARylation enhances its recruitment to DNA damage sites without interfering with TDP1 catalytic activity. TDP1-PARP1 complexes, in turn recruit X-ray repair cross-complementing protein 1 (XRCC1). This work identifies PARP1 as a key component driving the repair of trapped Top1cc by TDP1.
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Affiliation(s)
- Benu Brata Das
- Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA, Laboratory of Molecular Biology, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India, Biotechnology and Cell Signaling, UMR7242 CNRS, Université de Strasbourg, Laboratory of Excellence Medalis, ESBS, Blvd Sébastien Brant, CS 10413, 67412 Illkirch, France, CEA-DSV-iMETI-SEPIA, BP6, 92265 Fontenay-aux-Roses cedex, France and Laboratory of Molecular Parasitology, Indian Institute of Chemical Biology, Kolkata 700032, India
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SbcCD-mediated processing of covalent gyrase-DNA complex in Escherichia coli. Antimicrob Agents Chemother 2013; 57:5116-9. [PMID: 23917316 DOI: 10.1128/aac.00130-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Quinolones trap the covalent gyrase-DNA complex in Escherichia coli, leading to cell death. Processing activities for trapped covalent complex have not been characterized. A mutant strain lacking SbcCD nuclease activity was examined for both accumulation of gyrase-DNA complex and viability after quinolone treatment. Higher complex levels were found in ΔsbcCD cells than in wild-type cells after incubation with nalidixic acid and ciprofloxacin. However, SbcCD activity protected cells against the bactericidal action of nalidixic acid but not ciprofloxacin.
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Shiotani B, Nguyen HD, Håkansson P, Maréchal A, Tse A, Tahara H, Zou L. Two distinct modes of ATR activation orchestrated by Rad17 and Nbs1. Cell Rep 2013; 3:1651-62. [PMID: 23684611 DOI: 10.1016/j.celrep.2013.04.018] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 04/05/2013] [Accepted: 04/19/2013] [Indexed: 11/15/2022] Open
Abstract
The ATM- and Rad3-related (ATR) kinase is a master regulator of the DNA damage response, yet how ATR is activated toward different substrates is still poorly understood. Here, we show that ATR phosphorylates Chk1 and RPA32 through distinct mechanisms at replication-associated DNA double-stranded breaks (DSBs). In contrast to the rapid phosphorylation of Chk1, RPA32 is progressively phosphorylated by ATR at Ser33 during DSB resection prior to the phosphorylation of Ser4/Ser8 by DNA-PKcs. Surprisingly, despite its reliance on ATR and TopBP1, substantial RPA32 Ser33 phosphorylation occurs in a Rad17-independent but Nbs1-dependent manner in vivo and in vitro. Importantly, the role of Nbs1 in RPA32 phosphorylation can be separated from ATM activation and DSB resection, and it is dependent upon the interaction of Nbs1 with RPA. An Nbs1 mutant that is unable to bind RPA fails to support proper recovery of collapsed replication forks, suggesting that the Nbs1-mediated mode of ATR activation is important for the repair of replication-associated DSBs.
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Affiliation(s)
- Bunsyo Shiotani
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA.
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41
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Reynolds JJ, Stewart GS. A single strand that links multiple neuropathologies in human disease. ACTA ACUST UNITED AC 2013; 136:14-27. [PMID: 23365091 DOI: 10.1093/brain/aws310] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The development of the human central nervous system is a complex process involving highly coordinated periods of neuronal proliferation, migration and differentiation. Disruptions in these neurodevelopmental processes can result in microcephaly, a neuropathological disorder characterized by a reduction in skull circumference and total brain volume, whereas a failure to maintain neuronal health in the adult brain can lead to progressive neurodegeneration. Defects in the cellular pathways that detect and repair DNA damage are a common cause of both these neuropathologies and are associated with a growing number of hereditary human disorders. In particular, defects in the repair of DNA single strand breaks, one of the most commonly occurring types of DNA lesion, have been associated with three neuropathological diseases: ataxia oculomotor apraxia 1, spinocerebellar ataxia with neuronal neuropathy 1 and microcephaly, early-onset, intractable seizures and developmental delay. A striking similarity between these three human diseases is that they are all caused by mutations in DNA end processing factors, suggesting that a particularly crucial stage of DNA single strand break repair is the repair of breaks with 'damaged' termini. Additionally all three disorders lack any extraneurological symptoms, such as immunodeficiency and cancer predisposition, which are typically found in other human diseases associated with defective DNA repair. However despite these similarities, two of these disorders present with progressive cerebellar degeneration, whereas the third presents with severe microcephaly. This review discusses the molecular defects behind these disorders and presents several hypotheses based on current literature on a number of important questions, in particular, how do mutations in different end processing factors within the same DNA repair pathway lead to such different neuropathologies?
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Affiliation(s)
- John J Reynolds
- School of Cancer Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
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Westmoreland JW, Resnick MA. Coincident resection at both ends of random, γ-induced double-strand breaks requires MRX (MRN), Sae2 (Ctp1), and Mre11-nuclease. PLoS Genet 2013; 9:e1003420. [PMID: 23555316 PMCID: PMC3610664 DOI: 10.1371/journal.pgen.1003420] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 02/12/2013] [Indexed: 11/18/2022] Open
Abstract
Resection is an early step in homology-directed recombinational repair (HDRR) of DNA double-strand breaks (DSBs). Resection enables strand invasion as well as reannealing following DNA synthesis across a DSB to assure efficient HDRR. While resection of only one end could result in genome instability, it has not been feasible to address events at both ends of a DSB, or to distinguish 1- versus 2-end resections at random, radiation-induced "dirty" DSBs or even enzyme-induced "clean" DSBs. Previously, we quantitatively addressed resection and the role of Mre11/Rad50/Xrs2 complex (MRX) at random DSBs in circular chromosomes within budding yeast based on reduced pulsed-field gel electrophoretic mobility ("PFGE-shift"). Here, we extend PFGE analysis to a second dimension and demonstrate unique patterns associated with 0-, 1-, and 2-end resections at DSBs, providing opportunities to examine coincidence of resection. In G2-arrested WT, Δrad51 and Δrad52 cells deficient in late stages of HDRR, resection occurs at both ends of γ-DSBs. However, for radiation-induced and I-SceI-induced DSBs, 1-end resections predominate in MRX (MRN) null mutants with or without Ku70. Surprisingly, Sae2 (Ctp1/CtIP) and Mre11 nuclease-deficient mutants have similar responses, although there is less impact on repair. Thus, we provide direct molecular characterization of coincident resection at random, radiation-induced DSBs and show that rapid and coincident initiation of resection at γ-DSBs requires MRX, Sae2 protein, and Mre11 nuclease. Structural features of MRX complex are consistent with coincident resection being due to an ability to interact with both DSB ends to directly coordinate resection. Interestingly, coincident resection at clean I-SceI-induced breaks is much less dependent on Mre11 nuclease or Sae2, contrary to a strong dependence on MRX complex, suggesting different roles for these functions at "dirty" and clean DSB ends. These approaches apply to resection at other DSBs. Given evolutionary conservation, the observations are relevant to DNA repair in human cells.
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Affiliation(s)
- James W. Westmoreland
- Chromosome Stability Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America
| | - Michael A. Resnick
- Chromosome Stability Section, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America
- * E-mail:
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