1
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Herencia-Ropero A, Llop-Guevara A, Staniszewska AD, Domènech-Vivó J, García-Galea E, Moles-Fernández A, Pedretti F, Domènech H, Rodríguez O, Guzmán M, Arenas EJ, Verdaguer H, Calero-Nieto FJ, Talbot S, Tobalina L, Leo E, Lau A, Nuciforo P, Dienstmann R, Macarulla T, Arribas J, Díez O, Gutiérrez-Enríquez S, Forment JV, O'Connor MJ, Albertella M, Balmaña J, Serra V. The PARP1 selective inhibitor saruparib (AZD5305) elicits potent and durable antitumor activity in patient-derived BRCA1/2-associated cancer models. Genome Med 2024; 16:107. [PMID: 39187844 PMCID: PMC11348616 DOI: 10.1186/s13073-024-01370-z] [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: 02/13/2024] [Accepted: 07/26/2024] [Indexed: 08/28/2024] Open
Abstract
BACKGROUND Poly (ADP-ribose) polymerase 1 and 2 (PARP1/2) inhibitors (PARPi) are targeted therapies approved for homologous recombination repair (HRR)-deficient breast, ovarian, pancreatic, and prostate cancers. Since inhibition of PARP1 is sufficient to cause synthetic lethality in tumors with homologous recombination deficiency (HRD), PARP1 selective inhibitors such as saruparib (AZD5305) are being developed. It is expected that selective PARP1 inhibition leads to a safer profile that facilitates its combination with other DNA damage repair inhibitors. Here, we aimed to characterize the antitumor activity of AZD5305 in patient-derived preclinical models compared to the first-generation PARP1/2 inhibitor olaparib and to identify mechanisms of resistance. METHODS Thirteen previously characterized patient-derived tumor xenograft (PDX) models from breast, ovarian, and pancreatic cancer patients harboring germline pathogenic alterations in BRCA1, BRCA2, or PALB2 were used to evaluate the efficacy of AZD5305 alone or in combination with carboplatin or an ataxia telangiectasia and Rad3 related (ATR) inhibitor (ceralasertib) and compared it to the first-generation PARPi olaparib. We performed DNA and RNA sequencing as well as protein-based assays to identify mechanisms of acquired resistance to either PARPi. RESULTS AZD5305 showed superior antitumor activity than the first-generation PARPi in terms of preclinical complete response rate (75% vs. 37%). The median preclinical progression-free survival was significantly longer in the AZD5305-treated group compared to the olaparib-treated group (> 386 days vs. 90 days). Mechanistically, AZD5305 induced more replication stress and genomic instability than the PARP1/2 inhibitor olaparib in PARPi-sensitive tumors. All tumors at progression with either PARPi (39/39) showed increase of HRR functionality by RAD51 foci formation. The most prevalent resistance mechanisms identified were the acquisition of reversion mutations in BRCA1/BRCA2 and the accumulation of hypomorphic BRCA1. AZD5305 did not sensitize PDXs with acquired resistance to olaparib but elicited profound and durable responses when combined with carboplatin or ceralasertib in 3/6 and 5/5 models, respectively. CONCLUSIONS Collectively, these results show that the novel PARP1 selective inhibitor AZD5305 yields a potent antitumor response in PDX models with HRD and delays PARPi resistance alone or in combination with carboplatin or ceralasertib, which supports its use in the clinic as a new therapeutic option.
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Affiliation(s)
- Andrea Herencia-Ropero
- Experimental Therapeutics Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Carrer Natzaret 115-117, 08035, Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Autonomous University of Barcelona, Barcelona, Spain
| | - Alba Llop-Guevara
- Experimental Therapeutics Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Carrer Natzaret 115-117, 08035, Barcelona, Spain.
| | | | - Joanna Domènech-Vivó
- Hereditary Cancer Genetics Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Carrer Natzaret 115-117, 08035, Barcelona, Spain
- Programa de doctorat en Biomedicina, Universitat de Barcelona, Barcelona, Spain
| | - Eduardo García-Galea
- Oncology Data Science Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Alejandro Moles-Fernández
- Medicine Genetics Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
- Department of Clinical and Molecular Genetics, Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Flaminia Pedretti
- Experimental Therapeutics Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Carrer Natzaret 115-117, 08035, Barcelona, Spain
| | - Heura Domènech
- Experimental Therapeutics Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Carrer Natzaret 115-117, 08035, Barcelona, Spain
| | - Olga Rodríguez
- Experimental Therapeutics Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Carrer Natzaret 115-117, 08035, Barcelona, Spain
| | - Marta Guzmán
- Experimental Therapeutics Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Carrer Natzaret 115-117, 08035, Barcelona, Spain
| | - Enrique J Arenas
- Growth Factors Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Cáncer, Monforte de Lemos, Madrid, Spain
- Epigenetics Group, Josep Carreras Leukaemia Research Institute, Barcelona, Spain
| | - Helena Verdaguer
- Preclinical and Translational Research Program, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
- Gastrointestinal and Endocrine Tumor Unit, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | | | | | | | | | - Alan Lau
- Oncology R&D, AstraZeneca, Cambridge, UK
| | - Paolo Nuciforo
- Molecular Oncology Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Rodrigo Dienstmann
- Oncology Data Science Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Teresa Macarulla
- Preclinical and Translational Research Program, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
- Gastrointestinal and Endocrine Tumor Unit, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Joaquín Arribas
- Growth Factors Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Cáncer, Monforte de Lemos, Madrid, Spain
- Departament of Medicine and Life Sciences, Pompeu Fabra University, Barcelona, Spain
- Catalan Institution for Research and Advanced Studies, ICREA, Barcelona, Spain
- Cancer Research Program, The Hospital del Mar Research Institute, Barcelona, Spain
| | - Orland Díez
- Hereditary Cancer Genetics Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Carrer Natzaret 115-117, 08035, Barcelona, Spain
- Department of Clinical and Molecular Genetics, Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Sara Gutiérrez-Enríquez
- Hereditary Cancer Genetics Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Carrer Natzaret 115-117, 08035, Barcelona, Spain
| | | | | | | | - Judith Balmaña
- Hereditary Cancer Genetics Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Carrer Natzaret 115-117, 08035, Barcelona, Spain.
- Department of Medical Oncology, Vall d'Hebron Barcelona Hospital Campus, Autonomous University of Barcelona, Barcelona, Spain.
| | - Violeta Serra
- Experimental Therapeutics Group, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Carrer Natzaret 115-117, 08035, Barcelona, Spain.
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2
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Jordan MR, Oakley GG, Mayo LD, Balakrishnan L, Turchi JJ. The effect of replication protein A inhibition and post-translational modification on ATR kinase signaling. Sci Rep 2024; 14:19791. [PMID: 39187637 PMCID: PMC11347632 DOI: 10.1038/s41598-024-70589-y] [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: 06/12/2024] [Accepted: 08/19/2024] [Indexed: 08/28/2024] Open
Abstract
The ATR kinase responds to elevated levels of single-stranded DNA (ssDNA) to activate the G2/M checkpoint, regulate origin utilization, preserve fork stability, and allow DNA repair to ensure genome integrity. The intrinsic replication stress in cancer cells makes this pathway an attractive therapeutic target. The ssDNA that drives ATR signaling is sensed by the ssDNA-binding protein replication protein A (RPA), which acts as a platform for ATRIP recruitment and subsequent ATR activation by TopBP1. We have developed chemical RPA inhibitors (RPAi) that block RPA-ssDNA interactions (RPA-DBi) and RPA protein-protein interactions (RPA-PPIi); both activities are required for ATR activation. Here, we biochemically reconstitute the ATR kinase signaling pathway and demonstrate that RPA-DBi and RPA-PPIi abrogate ATR-dependent phosphorylation of target proteins with selectivity advantages over active site ATR inhibitors. We demonstrate that RPA post-translational modifications (PTMs) impact ATR kinase activation but do not alter sensitivity to RPAi. Specifically, phosphorylation of RPA32 and TopBP1 stimulate, while RPA70 acetylation does not affect ATR phosphorylation of target proteins. Collectively, this work reveals the RPAi mechanism of action to inhibit ATR signaling that can be regulated by RPA PTMs and offers insight into the anti-cancer activity of ATR pathway-targeted cancer therapeutics.
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Affiliation(s)
- Matthew R Jordan
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 64202, USA
| | - Greg G Oakley
- Department of Oral Biology, University of Nebraska Medical Center, Lincoln, NE, 68583, USA
| | - Lindsey D Mayo
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Lata Balakrishnan
- Department of Biology, School of Science, Indiana University Indianapolis, Indianapolis, IN, 46202, USA
| | - John J Turchi
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 64202, USA.
- NERx Biosciences Inc., Indianapolis, IN, 46202, USA.
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3
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Jordan MR, Oakley GG, Mayo LD, Balakrishnan L, Turchi JJ. The Effect of Replication Protein A Inhibition and Post-Translational Modification on ATR Kinase Signaling. RESEARCH SQUARE 2024:rs.3.rs-4570504. [PMID: 39108493 PMCID: PMC11302688 DOI: 10.21203/rs.3.rs-4570504/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 08/11/2024]
Abstract
The ATR kinase responds to elevated levels of single-stranded DNA (ssDNA) to activate the G2/M checkpoint, regulate origin utilization, preserve fork stability, and allow DNA repair towards ensuring genome integrity. The intrinsic replication stress in cancer cells makes this pathway an attractive therapeutic target. The ssDNA that drives ATR signaling is sensed by the ssDNA-binding protein replication protein A (RPA), which acts as a platform for ATRIP recruitment and subsequent ATR activation by TopBP1. We have developed chemical RPA inhibitors (RPAi) that block RPA-ssDNA interactions, termed RPA-DBi, and RPA protein-protein interactions, termed RPA-PPIi; both activities are required for ATR activation. Here, we employ a biochemically reconstituted ATR kinase signaling pathway and demonstrate that both RPA-DBi and RPA-PPIi abrogate ATR-dependent phosphorylation of downstream target proteins. We demonstrate that RPA post-translational modifications (PTMs) impact ATR kinase activation but do not alter sensitivity to RPAi. Specifically, phosphorylation of RPA32 and TopBP1 stimulate, while RPA70 acetylation has no effect on ATR phosphorylation of target proteins. Collectively, this work reveals the RPAi mechanism of action to inhibit ATR signaling that can be regulated by RPA PTMs and offers insight into the anti-cancer activity of ATR pathway targeted cancer therapeutics.
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4
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Rajpurohit YS, Sharma DK, Lal M, Soni I. A perspective on tumor radiation resistance following high-LET radiation treatment. J Cancer Res Clin Oncol 2024; 150:226. [PMID: 38696003 PMCID: PMC11065934 DOI: 10.1007/s00432-024-05757-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 04/22/2024] [Indexed: 05/05/2024]
Abstract
High-linear energy transfer (LET) radiation is a promising alternative to conventional low-LET radiation for therapeutic gain against cancer owing to its ability to induce complex and clustered DNA lesions. However, the development of radiation resistance poses a significant barrier. The potential molecular mechanisms that could confer resistance development are translesion synthesis (TLS), replication gap suppression (RGS) mechanisms, autophagy, epithelial-mesenchymal transition (EMT) activation, release of exosomes, and epigenetic changes. This article will discuss various types of complex clustered DNA damage, their repair mechanisms, mutagenic potential, and the development of radiation resistance strategies. Furthermore, it highlights the importance of careful consideration and patient selection when employing high-LET radiotherapy in clinical settings.
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Affiliation(s)
- Yogendra Singh Rajpurohit
- Molecular Biology Division, Bhabha Atomic Research Centre, 2-46-S, Modular Lab, A-Block, Mumbai, 400085, India.
- Homi Bhabha National Institute, DAE- Deemed University, Mumbai, 400094, India.
| | - Dhirendra Kumar Sharma
- Molecular Biology Division, Bhabha Atomic Research Centre, 2-46-S, Modular Lab, A-Block, Mumbai, 400085, India
| | - Mitu Lal
- Molecular Biology Division, Bhabha Atomic Research Centre, 2-46-S, Modular Lab, A-Block, Mumbai, 400085, India
| | - Ishu Soni
- Homi Bhabha National Institute, DAE- Deemed University, Mumbai, 400094, India
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5
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Lee CY, Chen YC, Huang YH, Lien Y, Huang CY. Cytotoxicity and Multi-Enzyme Inhibition of Nepenthes miranda Stem Extract on H838 Human Non-Small Cell Lung Cancer Cells and RPA32, Elastase, Tyrosinase, and Hyaluronidase Proteins. PLANTS (BASEL, SWITZERLAND) 2024; 13:797. [PMID: 38592804 PMCID: PMC10974603 DOI: 10.3390/plants13060797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/07/2024] [Accepted: 03/07/2024] [Indexed: 04/11/2024]
Abstract
The carnivorous pitcher plants of the genus Nepenthes have long been known for their ethnobotanical applications. In this study, we prepared various extracts from the pitcher, stem, and leaf of Nepenthes miranda using 100% ethanol and assessed their inhibitory effects on key enzymes related to skin aging, including elastase, tyrosinase, and hyaluronidase. The cytotoxicity of the stem extract of N. miranda on H838 human lung carcinoma cells were also characterized by effects on cell survival, migration, proliferation, apoptosis induction, and DNA damage. The cytotoxic efficacy of the extract was enhanced when combined with the chemotherapeutic agent 5-fluorouracil (5-FU), indicating a synergistic effect. Flow cytometry analysis suggested that the stem extract might suppress H838 cell proliferation by inducing G2 cell cycle arrest, thereby inhibiting carcinoma cell proliferation. Gas chromatography-mass spectrometry (GC-MS) enabled the tentative identification of the 15 most abundant compounds in the stem extract of N. miranda. Notably, the extract showed a potent inhibition of the human RPA32 protein (huRPA32), critical for DNA replication, suggesting a novel mechanism for its anticancer action. Molecular docking studies further substantiated the interaction between the extract and huRPA32, highlighting bioactive compounds, especially the two most abundant constituents, stigmast-5-en-3-ol and plumbagin, as potential inhibitors of huRPA32's DNA-binding activity, offering promising avenues for cancer therapy. Overall, our findings position the stem extract of N. miranda as a promising source of natural compounds for anticancer therapeutics and anti-skin-aging treatments, warranting further investigation into its molecular mechanisms and potential clinical applications.
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Affiliation(s)
- Ching-Yi Lee
- Department of Internal Medicine, Tao Yuan General Hospital, Ministry of Health and Welfare, Taoyuan 330, Taiwan
| | - Yu-Cheng Chen
- Department of Internal Medicine, Tao Yuan General Hospital, Ministry of Health and Welfare, Taoyuan 330, Taiwan
| | - Yen-Hua Huang
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 402, Taiwan
| | - Yi Lien
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Cheng-Yang Huang
- Department of Biomedical Sciences, Chung Shan Medical University, Taichung City 402, Taiwan
- Department of Medical Research, Chung Shan Medical University Hospital, Taichung City 402, Taiwan
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6
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Vasilopoulos SN, Güner H, Uça Apaydın M, Pavlopoulou A, Georgakilas AG. Dual Targeting of DNA Damage Response Proteins Implicated in Cancer Radioresistance. Genes (Basel) 2023; 14:2227. [PMID: 38137049 PMCID: PMC10742610 DOI: 10.3390/genes14122227] [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: 11/26/2023] [Revised: 12/13/2023] [Accepted: 12/13/2023] [Indexed: 12/24/2023] Open
Abstract
Ionizing radiation can induce different types of DNA lesions, leading to genomic instability and ultimately cell death. Radiation therapy or radiotherapy, a major modality in cancer treatment, harnesses the genotoxic potential of radiation to target and destroy cancer cells. Nevertheless, cancer cells have the capacity to develop resistance to radiation treatment (radioresistance), which poses a major obstacle in the effective management of cancer. It has been shown that administration of platinum-based drugs to cancer patients can increase tumor radiosensitivity, but despite this, it is associated with severe adverse effects. Several lines of evidence support that activation of the DNA damage response and repair machinery in the irradiated cancer cells enhances radioresistance and cellular survival through the efficient repair of DNA lesions. Therefore, targeting of key DNA damage repair factors would render cancer cells vulnerable to the irradiation effects, increase cancer cell killing, and reduce the risk of side effects on healthy tissue. Herein, we have employed a computer-aided drug design approach for generating ab initio a chemical compound with drug-like properties potentially targeting two proteins implicated in multiple DNA repair pathways. The findings of this study could be taken into consideration in clinical decision-making in terms of co-administering radiation with DNA damage repair factor-based drugs.
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Affiliation(s)
- Spyridon N. Vasilopoulos
- DNA Damage Laboratory, Physics Department, School of Applied Mathematical and Physical Sciences, National Technical University of Athens (NTUA), Zografou Campus, 15780 Athens, Greece;
- Department of Science and Mathematics, Deree-The American College of Greece, 6 Gravias Street, 15342 Athens, Greece
| | - Hüseyin Güner
- Izmir Biomedicine and Genome Center (IBG), 35340 Izmir, Turkey; (H.G.); (M.U.A.)
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, 35340 Izmir, Turkey
- Department of Molecular Biology and Genetics, Faculty of Life and Natural Science, Abdullah Gül University, 38080 Kayseri, Turkey
| | - Merve Uça Apaydın
- Izmir Biomedicine and Genome Center (IBG), 35340 Izmir, Turkey; (H.G.); (M.U.A.)
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, 35340 Izmir, Turkey
| | - Athanasia Pavlopoulou
- Izmir Biomedicine and Genome Center (IBG), 35340 Izmir, Turkey; (H.G.); (M.U.A.)
- Izmir International Biomedicine and Genome Institute, Dokuz Eylül University, 35340 Izmir, Turkey
| | - Alexandros G. Georgakilas
- DNA Damage Laboratory, Physics Department, School of Applied Mathematical and Physical Sciences, National Technical University of Athens (NTUA), Zografou Campus, 15780 Athens, Greece;
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7
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Feng Y, Jiang Y, Liu J, Liu J, Shi M, Chen J, Zhang J, Tian Y, Yang X, Liu H. Targeting RPA promotes autophagic flux and the antitumor response to radiation in nasopharyngeal carcinoma. J Transl Med 2023; 21:738. [PMID: 37858134 PMCID: PMC10585929 DOI: 10.1186/s12967-023-04574-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 09/28/2023] [Indexed: 10/21/2023] Open
Abstract
BACKGROUND Autophagy is involved in nasopharyngeal carcinoma (NPC) radioresistance. Replication protein A 1 (RPA1) and RPA3, substrates of the RPA complex, are potential therapeutic targets for reversing NPC radioresistance. Nevertheless, the role of RPA in autophagy is not adequately understood. This investigation was performed to reveal the cytotoxic mechanism of a pharmacologic RPA inhibitor (RPAi) in NPC cells and the underlying mechanism by which RPAi-mediated autophagy regulates NPC radiosensitivity. METHODS AND RESULTS We characterized a potent RPAi (HAMNO) that was substantially correlated with radiosensitivity enhancement and proliferative inhibition of in vivo and in NPC cell lines in vitro. We show that the RPAi induced autophagy at multiple levels by inducing autophagic flux, AMPK/mTOR pathway activation, and autophagy-related gene transcription by decreasing glycolytic function. We hypothesized that RPA inhibition impaired glycolysis and increased NPC dependence on autophagy. We further demonstrated that combining autophagy inhibition with chloroquine (CQ) treatment or genetic inhibition of the autophagy regulator ATG5 and RPAi treatment was more effective than either approach alone in enhancing the antitumor response of NPC to radiation. CONCLUSIONS Our study suggests that HAMNO is a potent RPAi that enhances radiosensitivity and induces autophagy in NPC cell lines by decreasing glycolytic function and activating autophagy-related genes. We suggest a novel treatment strategy in which pharmacological inhibitors that simultaneously disrupt RPA and autophagic processes improve NPC responsiveness to radiation.
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Affiliation(s)
- Yanchun Feng
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Yingming Jiang
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Department of General Surgery (Department of Gastric Surgery Section 2, ), The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Jun Liu
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Jiaqi Liu
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Mengchen Shi
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Junxiong Chen
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Jingdan Zhang
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Yu Tian
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Xiangling Yang
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China.
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
| | - Huanliang Liu
- Department of Clinical Laboratory, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Guangdong Institute of Gastroenterology, Guangzhou, 510655, China.
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
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8
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Dueva R, Krieger LM, Li F, Luo D, Xiao H, Stuschke M, Metzen E, Iliakis G. Chemical Inhibition of RPA by HAMNO Alters Cell Cycle Dynamics by Impeding DNA Replication and G2-to-M Transition but Has Little Effect on the Radiation-Induced DNA Damage Response. Int J Mol Sci 2023; 24:14941. [PMID: 37834389 PMCID: PMC10573259 DOI: 10.3390/ijms241914941] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 09/28/2023] [Accepted: 10/01/2023] [Indexed: 10/15/2023] Open
Abstract
Replication protein A (RPA) is the major single-stranded DNA (ssDNA) binding protein that is essential for DNA replication and processing of DNA double-strand breaks (DSBs) by homology-directed repair pathways. Recently, small molecule inhibitors have been developed targeting the RPA70 subunit and preventing RPA interactions with ssDNA and various DNA repair proteins. The rationale of this development is the potential utility of such compounds as cancer therapeutics, owing to their ability to inhibit DNA replication that sustains tumor growth. Among these compounds, (1Z)-1-[(2-hydroxyanilino) methylidene] naphthalen-2-one (HAMNO) has been more extensively studied and its efficacy against tumor growth was shown to arise from the associated DNA replication stress. Here, we study the effects of HAMNO on cells exposed to ionizing radiation (IR), focusing on the effects on the DNA damage response and the processing of DSBs and explore its potential as a radiosensitizer. We show that HAMNO by itself slows down the progression of cells through the cell cycle by dramatically decreasing DNA synthesis. Notably, HAMNO also attenuates the progression of G2-phase cells into mitosis by a mechanism that remains to be elucidated. Furthermore, HAMNO increases the fraction of chromatin-bound RPA in S-phase but not in G2-phase cells and suppresses DSB repair by homologous recombination. Despite these marked effects on the cell cycle and the DNA damage response, radiosensitization could neither be detected in exponentially growing cultures, nor in cultures enriched in G2-phase cells. Our results complement existing data on RPA inhibitors, specifically HAMNO, and suggest that their antitumor activity by replication stress induction may not extend to radiosensitization. However, it may render cells more vulnerable to other forms of DNA damaging agents through synthetically lethal interactions, which requires further investigation.
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Affiliation(s)
- Rositsa Dueva
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (L.M.K.); (F.L.); (D.L.); (H.X.)
- Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
| | - Lisa Marie Krieger
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (L.M.K.); (F.L.); (D.L.); (H.X.)
- Division of Experimental Radiation Biology, Department of Radiotherapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
| | - Fanghua Li
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (L.M.K.); (F.L.); (D.L.); (H.X.)
- West German Proton Therapy Centre Essen (WPE), 45147 Essen, Germany
| | - Daxian Luo
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (L.M.K.); (F.L.); (D.L.); (H.X.)
- Division of Experimental Radiation Biology, Department of Radiotherapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
| | - Huaping Xiao
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (L.M.K.); (F.L.); (D.L.); (H.X.)
- Division of Experimental Radiation Biology, Department of Radiotherapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
| | - Martin Stuschke
- Division of Experimental Radiation Biology, Department of Radiotherapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, 45147 Essen, Germany
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Eric Metzen
- Institute of Physiology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
| | - George Iliakis
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (L.M.K.); (F.L.); (D.L.); (H.X.)
- Division of Experimental Radiation Biology, Department of Radiotherapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany;
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9
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Mukherjee A, Hossain Z, Erben E, Ma S, Choi JY, Kim HS. Identification of a small-molecule inhibitor that selectively blocks DNA-binding by Trypanosoma brucei replication protein A1. Nat Commun 2023; 14:4390. [PMID: 37474515 PMCID: PMC10359466 DOI: 10.1038/s41467-023-39839-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 06/30/2023] [Indexed: 07/22/2023] Open
Abstract
Replication Protein A (RPA) is a broadly conserved complex comprised of the RPA1, 2 and 3 subunits. RPA protects the exposed single-stranded DNA (ssDNA) during DNA replication and repair. Using structural modeling, we discover an inhibitor, JC-229, that targets RPA1 in Trypanosoma brucei, the causative parasite of African trypanosomiasis. The inhibitor is highly toxic to T. brucei cells, while mildly toxic to human cells. JC-229 treatment mimics the effects of TbRPA1 depletion, including DNA replication inhibition and DNA damage accumulation. In-vitro ssDNA-binding assays demonstrate that JC-229 inhibits the activity of TbRPA1, but not the human ortholog. Indeed, despite the high sequence identity with T. cruzi and Leishmania RPA1, JC-229 only impacts the ssDNA-binding activity of TbRPA1. Site-directed mutagenesis confirms that the DNA-Binding Domain A (DBD-A) in TbRPA1 contains a JC-229 binding pocket. Residue Serine 105 determines specific binding and inhibition of TbRPA1 but not T. cruzi and Leishmania RPA1. Our data suggest a path toward developing and testing highly specific inhibitors for the treatment of African trypanosomiasis.
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Affiliation(s)
- Aditi Mukherjee
- Public Health Research Institute, Rutgers Biomedical Health Sciences, Newark, NJ, 07103, USA
| | - Zakir Hossain
- Department of Chemistry and Biochemistry, Queens College, New York, NY, 11367, USA
| | - Esteban Erben
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Provincia de Buenos Aires, Argentina
- Escuela de Bio y Nanotecnologías (EByN), Universidad Nacional de San Martín, San Martín, Provincia de Buenos Aires, Argentina
| | - Shuai Ma
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Jun Yong Choi
- Department of Chemistry and Biochemistry, Queens College, New York, NY, 11367, USA.
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA.
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, USA.
| | - Hee-Sook Kim
- Public Health Research Institute, Rutgers Biomedical Health Sciences, Newark, NJ, 07103, USA.
- Department of Microbiology, Biochemistry, and Molecular Genetics, New Jersey Medical School, Rutgers Biomedical Health Sciences, Newark, NJ, 07103, USA.
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10
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Ning K, Kuz CA, Cheng F, Feng Z, Yan Z, Qiu J. Adeno-Associated Virus Monoinfection Induces a DNA Damage Response and DNA Repair That Contributes to Viral DNA Replication. mBio 2023; 14:e0352822. [PMID: 36719192 PMCID: PMC9973366 DOI: 10.1128/mbio.03528-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 01/03/2023] [Indexed: 02/01/2023] Open
Abstract
Adeno-associated virus (AAV) belongs to the Dependoparvovirus genus of the Parvoviridae family. AAV replication relies on a helper virus, such as adenovirus (Ad). Co-infection of AAV and Ad induces a DNA damage response (DDR), although its function in AAV DNA replication remains unknown. In this study, monoinfection of AAV2 in HEK293T cells expressing a minimal set of Ad helper genes was used to investigate the role of the DDR solely induced by AAV. We found that AAV2 DNA replication, but not single stranded (ss)DNA genome accumulation and Rep expression only, induced a robust DDR in HEK293T cells. The induced DDR featured the phosphorylation of replication protein A32 (RPA32), histone variant H2AX (H2A histone family member X), and all 3 phosphatidylinositol 3-kinase-related kinases (PIKKs). We also found that the kinase ataxia telangiectasia and Rad3-related protein (ATR) plays a major role in AAV2 DNA replication and that Y family DNA repair DNA polymerases η (Pol η) and Pol κ contribute to AAV2 DNA replication both in vitro and in HEK293T cells. Knockout of Pol η and Pol κ in HEK293T cells significantly decreased wild-type AAV2 replication and recombinant AAV2 production. Thus, our study has proven that AAV2 DNA replication induces a DDR, which in turn initiates a DNA repairing process that partially contributes to the viral genome amplification in HEK293T cells. IMPORTANCE Recombinant AAV (rAAV) has emerged as one of the preferred delivery vectors for clinical gene therapy. rAAV production in HEK293 cells by transfection of a rAAV transgene plasmid, an AAV Rep and Cap expression packaging plasmid, and an Ad helper plasmid remains the popular method. Here, we demonstrated that the high fidelity Y family DNA repair DNA polymerase, Pol η, and Pol κ, plays a significant role in AAV DNA replication and rAAV production in HEK293T cells. Understanding the AAV DNA replication mechanism in HEK293T cells could provide clues to increase rAAV vector yield produced from the transfection method. We also provide evidence that the ATR-mediated DNA repair process through Pol η and Pol κ is one of the mechanisms to amplify AAV genome, which could explain AAV replication and rAAV ssDNA genome conversion in mitotic quiescent cells.
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Affiliation(s)
- Kang Ning
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Cagla Aksu Kuz
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Fang Cheng
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Zehua Feng
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, Iowa, USA
| | - Ziying Yan
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, Iowa, USA
| | - Jianming Qiu
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA
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11
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SN-38 Sensitizes BRCA-Proficient Ovarian Cancers to PARP Inhibitors through Inhibiting Homologous Recombination Repair. DISEASE MARKERS 2022; 2022:7243146. [PMID: 36267463 PMCID: PMC9578876 DOI: 10.1155/2022/7243146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 09/16/2022] [Indexed: 11/20/2022]
Abstract
As a multifunctional protein posttranslational modification enzyme in eukaryotic cells, Poly-ADP-ribose polymerase (PARP) acts as a DNA damage sensor, which helps to repair DNA damage through recruiting repair proteins to the DNA break sites. PARP inhibitors offer a significant clinical benefit for ovarian cancer with BRCA1/2 mutations. However, the majority of ovarian cancer patients harbor wild-type (WT) BRCA1/2 status, which narrows its clinical application. Here, we identified a small compound, SN-38, a CPT analog, which sensitizes BRCA-proficient ovarian cancer cells to PARP inhibitor treatment by inhibiting homologous recombination (HR) repair. SN-38 treatment greatly enhanced PARP inhibitor olaparib induced DNA double-strand breaks (DSBs) and DNA replication stress. Meanwhile, the combination of SN-38 and olaparib synergistically induced apoptosis in ovarian cancer. Furthermore, combination administration of SN-38 and olaparib induced synergistic antitumor efficacy in an ovarian cancer xenograft model in vivo. Therefore, our study provides a novel therapeutic strategy to optimize PARP inhibitor therapy for patients with BRCA-proficient ovarian cancer.
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12
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Jang SW, Kim JM. The RPA inhibitor HAMNO sensitizes Fanconi anemia pathway-deficient cells. Cell Cycle 2022; 21:1468-1478. [PMID: 35506981 PMCID: PMC9278452 DOI: 10.1080/15384101.2022.2074200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The Fanconi anemia (FA) DNA repair pathway is required for DNA inter-strand crosslink (ICL) repair. Besides its role in ICL repair, FA proteins play a central role in stabilizing stalled replication forks, thereby ensuring genome integrity. We previously demonstrated that depletion of replication protein A (RPA) induces the activation of FA pathway leading to FANCD2 monoubiquitination and FANCD2 foci formation. Thus, we speculated that FA-deficient cells would be more sensitive to RPA inhibition compared to FA-proficient cells. Following treatment with RPA inhibitor HAMNO, we observed significant induction in FANCD2 monoubiquitination and foci formation as observed in RPA depletion. In addition, HAMNO treatment caused increased levels of ϒ-H2AX and S-phase accumulation in FA-deficient cells. Importantly, FA-deficient cells showed more increased sensitivity to HAMNO than FA-proficient cells. Moreover, in combination with cisplatin, HAMNO further enhanced the cytotoxicity of cisplatin in FA-deficient cells, while being less toxic against FA-proficient cells. This result suggests that RPA inhibition might be a potential therapeutic candidate for the treatment of FA pathway-deficient tumors.
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Affiliation(s)
- Seok-Won Jang
- Department of Pharmacology, Chonnam National University Medical School, Jellanamdo, 58128, Republic of Korea
| | - Jung Min Kim
- Department of Pharmacology, Chonnam National University Medical School, Jellanamdo, 58128, Republic of Korea
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13
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Kelm JM, Samarbakhsh A, Pillai A, VanderVere-Carozza PS, Aruri H, Pandey DS, Pawelczak KS, Turchi JJ, Gavande NS. Recent Advances in the Development of Non-PIKKs Targeting Small Molecule Inhibitors of DNA Double-Strand Break Repair. Front Oncol 2022; 12:850883. [PMID: 35463312 PMCID: PMC9020266 DOI: 10.3389/fonc.2022.850883] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 02/22/2022] [Indexed: 01/09/2023] Open
Abstract
The vast majority of cancer patients receive DNA-damaging drugs or ionizing radiation (IR) during their course of treatment, yet the efficacy of these therapies is tempered by DNA repair and DNA damage response (DDR) pathways. Aberrations in DNA repair and the DDR are observed in many cancer subtypes and can promote de novo carcinogenesis, genomic instability, and ensuing resistance to current cancer therapy. Additionally, stalled or collapsed DNA replication forks present a unique challenge to the double-strand DNA break (DSB) repair system. Of the various inducible DNA lesions, DSBs are the most lethal and thus desirable in the setting of cancer treatment. In mammalian cells, DSBs are typically repaired by the error prone non-homologous end joining pathway (NHEJ) or the high-fidelity homology directed repair (HDR) pathway. Targeting DSB repair pathways using small molecular inhibitors offers a promising mechanism to synergize DNA-damaging drugs and IR while selective inhibition of the NHEJ pathway can induce synthetic lethality in HDR-deficient cancer subtypes. Selective inhibitors of the NHEJ pathway and alternative DSB-repair pathways may also see future use in precision genome editing to direct repair of resulting DSBs created by the HDR pathway. In this review, we highlight the recent advances in the development of inhibitors of the non-phosphatidylinositol 3-kinase-related kinases (non-PIKKs) members of the NHEJ, HDR and minor backup SSA and alt-NHEJ DSB-repair pathways. The inhibitors described within this review target the non-PIKKs mediators of DSB repair including Ku70/80, Artemis, DNA Ligase IV, XRCC4, MRN complex, RPA, RAD51, RAD52, ERCC1-XPF, helicases, and DNA polymerase θ. While the DDR PIKKs remain intensely pursued as therapeutic targets, small molecule inhibition of non-PIKKs represents an emerging opportunity in drug discovery that offers considerable potential to impact cancer treatment.
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Affiliation(s)
- Jeremy M. Kelm
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States
| | - Amirreza Samarbakhsh
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States
| | - Athira Pillai
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States
| | | | - Hariprasad Aruri
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States
| | - Deepti S. Pandey
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States
| | | | - John J. Turchi
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States,NERx Biosciences, Indianapolis, IN, United States,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Navnath S. Gavande
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States,Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, United States,*Correspondence: Navnath S. Gavande, ; orcid.org/0000-0002-2413-0235
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14
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A clinically relevant heterozygous ATR mutation sensitizes colorectal cancer cells to replication stress. Sci Rep 2022; 12:5422. [PMID: 35361811 PMCID: PMC8971416 DOI: 10.1038/s41598-022-09308-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 03/03/2022] [Indexed: 12/21/2022] Open
Abstract
Colorectal cancer (CRC) ranks third among the most frequent malignancies and represents the second most common cause of cancer-related deaths worldwide. By interfering with the DNA replication process of cancer cells, several chemotherapeutic molecules used in CRC therapy induce replication stress (RS). At the cellular level, this stress is managed by the ATR-CHK1 pathway, which activates the replication checkpoint. In recent years, the therapeutic value of targeting this pathway has been demonstrated. Moreover, MSI + (microsatellite instability) tumors frequently harbor a nonsense, heterozygous mutation in the ATR gene. Using isogenic HCT116 clones, we showed that this mutation of ATR sensitizes the cells to several drugs, including SN-38 (topoisomerase I inhibitor) and VE-822 (ATR inhibitor) and exacerbates their synergistic effects. We showed that this mutation bottlenecks the replication checkpoint leading to extensive DNA damage. The combination of VE-822 and SN-38 induces an exhaustion of RPA and a subsequent replication catastrophe. Surviving cells complete replication and accumulate in G2 in a DNA-PK-dependent manner, protecting them from cell death. Together, our results suggest that RPA and DNA-PK represent promising therapeutic targets to optimize the inhibition of the ATR-CHK1 pathway in oncology. Ultimately, ATR frameshift mutations found in patients may also represent important prognostic factors.
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15
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Nickoloff JA, Sharma N, Taylor L, Allen SJ, Hromas R. Nucleases and Co-Factors in DNA Replication Stress Responses. DNA 2022; 2:68-85. [PMID: 36203968 PMCID: PMC9534323 DOI: 10.3390/dna2010006] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
DNA replication stress is a constant threat that cells must manage to proliferate and maintain genome integrity. DNA replication stress responses, a subset of the broader DNA damage response (DDR), operate when the DNA replication machinery (replisome) is blocked or replication forks collapse during S phase. There are many sources of replication stress, such as DNA lesions caused by endogenous and exogenous agents including commonly used cancer therapeutics, and difficult-to-replicate DNA sequences comprising fragile sites, G-quadraplex DNA, hairpins at trinucleotide repeats, and telomeres. Replication stress is also a consequence of conflicts between opposing transcription and replication, and oncogenic stress which dysregulates replication origin firing and fork progression. Cells initially respond to replication stress by protecting blocked replisomes, but if the offending problem (e.g., DNA damage) is not bypassed or resolved in a timely manner, forks may be cleaved by nucleases, inducing a DNA double-strand break (DSB) and providing a means to accurately restart stalled forks via homologous recombination. However, DSBs pose their own risks to genome stability if left unrepaired or misrepaired. Here we focus on replication stress response systems, comprising DDR signaling, fork protection, and fork processing by nucleases that promote fork repair and restart. Replication stress nucleases include MUS81, EEPD1, Metnase, CtIP, MRE11, EXO1, DNA2-BLM, SLX1-SLX4, XPF-ERCC1-SLX4, Artemis, XPG, and FEN1. Replication stress factors are important in cancer etiology as suppressors of genome instability associated with oncogenic mutations, and as potential cancer therapy targets to enhance the efficacy of chemo- and radiotherapeutics.
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Affiliation(s)
- Jac A. Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Neelam Sharma
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Lynn Taylor
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Sage J. Allen
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Robert Hromas
- Division of Hematology and Medical Oncology, Department of Medicine and the Mays Cancer Center, University of Texas Health Science Center, San Antonio, TX 78229, USA
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16
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Abstract
DNA repair and DNA damage signaling pathways are critical for the maintenance of genomic stability. Defects of DNA repair and damage signaling contribute to tumorigenesis, but also render cancer cells vulnerable to DNA damage and reliant on remaining repair and signaling activities. Here, we review the major classes of DNA repair and damage signaling defects in cancer, the genomic instability that they give rise to, and therapeutic strategies to exploit the resulting vulnerabilities. Furthermore, we discuss the impacts of DNA repair defects on both targeted therapy and immunotherapy, and highlight emerging principles for targeting DNA repair defects in cancer therapy.
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Affiliation(s)
- Jessica L Hopkins
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, Massachusetts 02129, USA
| | - Li Lan
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, Massachusetts 02129, USA
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Lee Zou
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, Massachusetts 02129, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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17
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Liu Y, Zheng C, Huang Y, He M, Xu WW, Li B. Molecular mechanisms of chemo- and radiotherapy resistance and the potential implications for cancer treatment. MedComm (Beijing) 2021; 2:315-340. [PMID: 34766149 PMCID: PMC8554658 DOI: 10.1002/mco2.55] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 12/25/2020] [Accepted: 12/28/2020] [Indexed: 12/24/2022] Open
Abstract
Cancer is a leading cause of death worldwide. Surgery is the primary treatment approach for cancer, but the survival rate is very low due to the rapid progression of the disease and presence of local and distant metastasis at diagnosis. Adjuvant chemotherapy and radiotherapy are important components of the multidisciplinary approaches for cancer treatment. However, resistance to radiotherapy and chemotherapy may result in treatment failure or even cancer recurrence. Radioresistance in cancer is often caused by the repair response to radiation-induced DNA damage, cell cycle dysregulation, cancer stem cells (CSCs) resilience, and epithelial-mesenchymal transition (EMT). Understanding the molecular alterations that lead to radioresistance may provide new diagnostic markers and therapeutic targets to improve radiotherapy efficacy. Patients who develop resistance to chemotherapy drugs cannot benefit from the cytotoxicity induced by the prescribed drug and will likely have a poor outcome with these treatments. Chemotherapy often shows a low response rate due to various drug resistance mechanisms. This review focuses on the molecular mechanisms of radioresistance and chemoresistance in cancer and discusses recent developments in therapeutic strategies targeting chemoradiotherapy resistance to improve treatment outcomes.
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Affiliation(s)
- Ya‐Ping Liu
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education InstitutesInstitute of Life and Health EngineeringJinan UniversityGuangzhouP. R. China
| | - Can‐Can Zheng
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education InstitutesInstitute of Life and Health EngineeringJinan UniversityGuangzhouP. R. China
| | - Yun‐Na Huang
- MOE Key Laboratory of Tumor Molecular Biology and Guangdong Provincial Key Laboratory of Bioengineering MedicineNational Engineering Research Center of Genetic MedicineInstitute of BiomedicineCollege of Life Science and TechnologyJinan UniversityGuangzhouP. R. China
| | - Ming‐Liang He
- Department of Biomedical SciencesCity University of Hong KongHong KongChina
| | - Wen Wen Xu
- MOE Key Laboratory of Tumor Molecular Biology and Guangdong Provincial Key Laboratory of Bioengineering MedicineNational Engineering Research Center of Genetic MedicineInstitute of BiomedicineCollege of Life Science and TechnologyJinan UniversityGuangzhouP. R. China
| | - Bin Li
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education InstitutesInstitute of Life and Health EngineeringJinan UniversityGuangzhouP. R. China
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18
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Transcription/Replication Conflicts in Tumorigenesis and Their Potential Role as Novel Therapeutic Targets in Multiple Myeloma. Cancers (Basel) 2021; 13:cancers13153755. [PMID: 34359660 PMCID: PMC8345052 DOI: 10.3390/cancers13153755] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/13/2021] [Accepted: 07/22/2021] [Indexed: 12/24/2022] Open
Abstract
Simple Summary Multiple myeloma is a hematologic cancer characterized by the accumulation of malignant plasma cells in the bone marrow. It remains a mostly incurable disease due to the inability to overcome refractory disease and drug-resistant relapse. Oncogenic transformation of PC in multiple myeloma is thought to occur within the secondary lymphoid organs. However, the precise molecular events leading to myelomagenesis remain obscure. Here, we identified genes involved in the prevention and the resolution of conflicts between the replication and transcription significantly overexpressed during the plasma cell differentiation process and in multiple myeloma cells. We discussed the potential role of these factors in myelomagenesis and myeloma biology. The specific targeting of these factors might constitute a new therapeutic strategy in multiple myeloma. Abstract Plasma cells (PCs) have an essential role in humoral immune response by secretion of antibodies, and represent the final stage of B lymphocytes differentiation. During this differentiation, the pre-plasmablastic stage is characterized by highly proliferative cells that start to secrete immunoglobulins (Igs). Thus, replication and transcription must be tightly regulated in these cells to avoid transcription/replication conflicts (TRCs), which could increase replication stress and lead to genomic instability. In this review, we analyzed expression of genes involved in TRCs resolution during B to PC differentiation and identified 41 genes significantly overexpressed in the pre-plasmablastic stage. This illustrates the importance of mechanisms required for adequate processing of TRCs during PCs differentiation. Furthermore, we identified that several of these factors were also found overexpressed in purified PCs from patients with multiple myeloma (MM) compared to normal PCs. Malignant PCs produce high levels of Igs concomitantly with cell cycle deregulation. Therefore, increasing the TRCs occurring in MM cells could represent a potent therapeutic strategy for MM patients. Here, we describe the potential roles of TRCs resolution factors in myelomagenesis and discuss the therapeutic interest of targeting the TRCs resolution machinery in MM.
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19
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Par S, Vaides S, VanderVere-Carozza PS, Pawelczak KS, Stewart J, Turchi JJ. OB-Folds and Genome Maintenance: Targeting Protein-DNA Interactions for Cancer Therapy. Cancers (Basel) 2021; 13:3346. [PMID: 34283091 PMCID: PMC8269290 DOI: 10.3390/cancers13133346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/09/2021] [Accepted: 07/01/2021] [Indexed: 12/14/2022] Open
Abstract
Genome stability and maintenance pathways along with their requisite proteins are critical for the accurate duplication of genetic material, mutation avoidance, and suppression of human diseases including cancer. Many of these proteins participate in these pathways by binding directly to DNA, and a subset employ oligonucleotide/oligosaccharide binding folds (OB-fold) to facilitate the protein-DNA interactions. OB-fold motifs allow for sequence independent binding to single-stranded DNA (ssDNA) and can serve to position specific proteins at specific DNA structures and then, via protein-protein interaction motifs, assemble the machinery to catalyze the replication, repair, or recombination of DNA. This review provides an overview of the OB-fold structural organization of some of the most relevant OB-fold containing proteins for oncology and drug discovery. We discuss their individual roles in DNA metabolism, progress toward drugging these motifs and their utility as potential cancer therapeutics. While protein-DNA interactions were initially thought to be undruggable, recent reports of success with molecules targeting OB-fold containing proteins suggest otherwise. The potential for the development of agents targeting OB-folds is in its infancy, but if successful, would expand the opportunities to impinge on genome stability and maintenance pathways for more effective cancer treatment.
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Affiliation(s)
- Sui Par
- Indiana University Comprehensive Cancer Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (S.P.); (S.V.)
| | - Sofia Vaides
- Indiana University Comprehensive Cancer Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (S.P.); (S.V.)
| | | | | | - Jason Stewart
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA;
| | - John J. Turchi
- Indiana University Comprehensive Cancer Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (S.P.); (S.V.)
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
- NERx Biosciences, Indianapolis, IN 46202, USA;
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Li L, Kumar AK, Hu Z, Guo Z. Small Molecule Inhibitors Targeting Key Proteins in the DNA Damage Response for Cancer Therapy. Curr Med Chem 2021; 28:963-985. [PMID: 32091326 DOI: 10.2174/0929867327666200224102309] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 01/17/2020] [Accepted: 01/29/2020] [Indexed: 11/22/2022]
Abstract
DNA damage response (DDR) is a complicated interactional pathway. Defects that occur in subordinate pathways of the DDR pathway can lead to genomic instability and cancer susceptibility. Abnormal expression of some proteins in DDR, especially in the DNA repair pathway, are associated with the subsistence and resistance of cancer cells. Therefore, the development of small molecule inhibitors targeting the chief proteins in the DDR pathway is an effective strategy for cancer therapy. In this review, we summarize the development of small molecule inhibitors targeting chief proteins in the DDR pathway, particularly focusing on their implications for cancer therapy. We present the action mode of DDR molecule inhibitors in preclinical studies and clinical cancer therapy, including monotherapy and combination therapy with chemotherapeutic drugs or checkpoint suppression therapy.
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Affiliation(s)
- Lulu Li
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing 210023, China
| | - Alagamuthu Karthick Kumar
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing 210023, China
| | - Zhigang Hu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing 210023, China
| | - Zhigang Guo
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 1 WenYuan Road, Nanjing 210023, China
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21
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Dueva R, Iliakis G. Replication protein A: a multifunctional protein with roles in DNA replication, repair and beyond. NAR Cancer 2020; 2:zcaa022. [PMID: 34316690 PMCID: PMC8210275 DOI: 10.1093/narcan/zcaa022] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/23/2020] [Accepted: 08/27/2020] [Indexed: 02/07/2023] Open
Abstract
Single-stranded DNA (ssDNA) forms continuously during DNA replication and is an important intermediate during recombination-mediated repair of damaged DNA. Replication protein A (RPA) is the major eukaryotic ssDNA-binding protein. As such, RPA protects the transiently formed ssDNA from nucleolytic degradation and serves as a physical platform for the recruitment of DNA damage response factors. Prominent and well-studied RPA-interacting partners are the tumor suppressor protein p53, the RAD51 recombinase and the ATR-interacting proteins ATRIP and ETAA1. RPA interactions are also documented with the helicases BLM, WRN and SMARCAL1/HARP, as well as the nucleotide excision repair proteins XPA, XPG and XPF–ERCC1. Besides its well-studied roles in DNA replication (restart) and repair, accumulating evidence shows that RPA is engaged in DNA activities in a broader biological context, including nucleosome assembly on nascent chromatin, regulation of gene expression, telomere maintenance and numerous other aspects of nucleic acid metabolism. In addition, novel RPA inhibitors show promising effects in cancer treatment, as single agents or in combination with chemotherapeutics. Since the biochemical properties of RPA and its roles in DNA repair have been extensively reviewed, here we focus on recent discoveries describing several non-canonical functions.
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Affiliation(s)
- Rositsa Dueva
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122 Essen, Germany
| | - George Iliakis
- Institute of Medical Radiation Biology, University of Duisburg-Essen Medical School, 45122 Essen, Germany
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22
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Nguyen DD, Kim EY, Sang PB, Chai W. Roles of OB-Fold Proteins in Replication Stress. Front Cell Dev Biol 2020; 8:574466. [PMID: 33043007 PMCID: PMC7517361 DOI: 10.3389/fcell.2020.574466] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 08/25/2020] [Indexed: 12/20/2022] Open
Abstract
Accurate DNA replication is essential for maintaining genome stability. However, this stability becomes vulnerable when replication fork progression is stalled or slowed - a condition known as replication stress. Prolonged fork stalling can cause DNA damage, leading to genome instabilities. Thus, cells have developed several pathways and a complex set of proteins to overcome the challenge at stalled replication forks. Oligonucleotide/oligosaccharide binding (OB)-fold containing proteins are a group of proteins that play a crucial role in fork protection and fork restart. These proteins bind to single-stranded DNA with high affinity and prevent premature annealing and unwanted nuclease digestion. Among these OB-fold containing proteins, the best studied in eukaryotic cells are replication protein A (RPA) and breast cancer susceptibility protein 2 (BRCA2). Recently, another RPA-like protein complex CTC1-STN1-TEN1 (CST) complex has been found to counter replication perturbation. In this review, we discuss the latest findings on how these OB-fold containing proteins (RPA, BRCA2, CST) cooperate to safeguard DNA replication and maintain genome stability.
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Affiliation(s)
| | | | | | - Weihang Chai
- Department of Cancer Biology, Cardinal Bernardin Cancer Center, Loyola University Chicago Stritch School of Medicine, Maywood, IL, United States
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23
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Hu Y, Guo M. Synthetic lethality strategies: Beyond BRCA1/2 mutations in pancreatic cancer. Cancer Sci 2020; 111:3111-3121. [PMID: 32639661 PMCID: PMC7469842 DOI: 10.1111/cas.14565] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 06/15/2020] [Accepted: 07/02/2020] [Indexed: 12/11/2022] Open
Abstract
Cancer cells are often characterized by abnormalities in DNA damage response including defects in cell cycle checkpoints and/or DNA repair. Synthetic lethality between DNA damage repair (DDR) pathways has provided a paradigm for cancer therapy by targeting DDR. The successful example is that cancer cells with BRCA1/2 mutations are sensitized to poly(adenosine diphosphate [ADP]-ribose)polymerase (PARP) inhibitors. Beyond the narrow scope of defects in the BRCA pathway, "BRCAness" provides more opportunities for synthetic lethality strategy. In human pancreatic cancer, frequent mutations were found in cell cycle and DDR genes, including P16, P73, APC, MLH1, ATM, PALB2, and MGMT. Combined DDR inhibitors and chemotherapeutic agents are under preclinical or clinical trials. Promoter region methylation was found frequently in cell cycle and DDR genes. Epigenetics joins the Knudson's "hit" theory and "BRCAness." Aberrant epigenetic changes in cell cycle or DDR regulators may serve as a new avenue for synthetic lethality strategy in pancreatic cancer.
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Affiliation(s)
- Yunlong Hu
- Department of Gastroenterology and Hepatology, Chinese PLA General Hospital, Beijing, China
| | - Mingzhou Guo
- Department of Gastroenterology and Hepatology, Chinese PLA General Hospital, Beijing, China.,Henan Key Laboratory for Esophageal Cancer Research, Zhengzhou University, Zhengzhou, China.,State Key Laboratory of Kidney Diseases, Chinese PLA General Hospital, Beijing, China
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24
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Gavande NS, VanderVere-Carozza PS, Pawelczak KS, Vernon TL, Jordan MR, Turchi JJ. Structure-Guided Optimization of Replication Protein A (RPA)-DNA Interaction Inhibitors. ACS Med Chem Lett 2020; 11:1118-1124. [PMID: 32550990 DOI: 10.1021/acsmedchemlett.9b00440] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/02/2020] [Indexed: 12/12/2022] Open
Abstract
Replication protein A (RPA) is the major human single stranded DNA (ssDNA)-binding protein, playing essential roles in DNA replication, repair, recombination, and DNA-damage response (DDR). Inhibition of RPA-DNA interactions represents a therapeutic strategy for cancer drug discovery and has great potential to provide single agent anticancer activity and to synergize with both common DNA damaging chemotherapeutics and newer targeted anticancer agents. In this letter, a new series of analogues based on our previously reported TDRL-551 (4) compound were designed to improve potency and physicochemical properties. Molecular docking studies guided molecular insights, and further SAR exploration led to the identification of a series of novel compounds with low micromolar RPA inhibitory activity, increased solubility, and excellent cellular up-take. Among a series of analogues, compounds 43, 44, 45, and 46 hold promise for further development of novel anticancer agents.
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Affiliation(s)
- Navnath S. Gavande
- Department of Medicine, Indiana University School of Medicine (IUSM), Indianapolis, Indiana 46202, United States
- Department of Pharmaceutical Sciences, Wayne State University College of Pharmacy and Health Sciences, Detroit, Michigan 48201, United States
| | - Pamela S. VanderVere-Carozza
- Department of Medicine, Indiana University School of Medicine (IUSM), Indianapolis, Indiana 46202, United States
| | - Katherine S. Pawelczak
- NERx Biosciences, 212 W 10th Street Suite A480, Indianapolis, Indiana 46202, United States
| | - Tyler L. Vernon
- Department of Medicine, Indiana University School of Medicine (IUSM), Indianapolis, Indiana 46202, United States
| | - Matthew R. Jordan
- Department of Medicine, Indiana University School of Medicine (IUSM), Indianapolis, Indiana 46202, United States
| | - John J. Turchi
- Department of Medicine, Indiana University School of Medicine (IUSM), Indianapolis, Indiana 46202, United States
- NERx Biosciences, 212 W 10th Street Suite A480, Indianapolis, Indiana 46202, United States
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine (IUSM), Indianapolis, Indiana 46202, United States
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25
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Amir M, Mohammad T, Dohare R, Islam A, Ahmad F, Imtaiyaz Hassan M. Structure, function and therapeutic implications of OB-fold proteins: A lesson from past to present. Brief Funct Genomics 2020; 19:377-389. [PMID: 32393969 DOI: 10.1093/bfgp/elaa008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Oligonucleotide/oligosaccharide-binding (OB)-fold proteins play essential roles in the regulation of genome and its correct transformation to the subsequent generation. To maintain the genomic stability, OB-fold proteins are implicated in various cellular processes including DNA replication, DNA repair, cell cycle regulation and maintenance of telomere. The diverse functional spectrums of OB-fold proteins are mainly due to their involvement in protein-DNA and protein-protein complexes. Mutations and consequential structural alteration in the OB-fold proteins often lead to severe diseases. Here, we have investigated the structure, function and mode of action of OB-fold proteins (RPA, BRCA2, DNA ligases and SSBs1/2) in cellular pathways and their relationship with diseases and their possible use in therapeutic intervention. Due to the crucial role of OB-fold proteins in regulating the key physiological process, a detailed structural understanding in the context of underlying mechanism of action and cellular complexity offers a new avenue to target OB-proteins for therapeutic intervention.
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26
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Replication Protein A (RPA) Mediates Radio-Resistance of Glioblastoma Cancer Stem-Like Cells. Int J Mol Sci 2020; 21:ijms21051588. [PMID: 32111042 PMCID: PMC7084771 DOI: 10.3390/ijms21051588] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/14/2020] [Accepted: 02/24/2020] [Indexed: 12/02/2022] Open
Abstract
Glioblastoma (GBM) is among the deadliest of solid tumors with median survival rates of approximately 12–15 months despite maximal therapeutic intervention. A rare population of self-renewing cells referred to as GBM cancer stem-like cells (GSCs) are believed to be the source of inevitable recurrence in GBM. GSCs exhibit preferential activation of the DNA damage response pathway (DDR) and evade ionizing radiation (IR) therapy by superior execution of DNA repair compared to their differentiated counterparts, differentiated GBM cells (DGCs). Replication Protein A (RPA) plays a central role in most of the DNA metabolic processes essential for genomic stability, including DNA repair. Here, we show that RPA is preferentially expressed by GSCs and high RPA expression informs poor glioma patient survival. RPA loss either by shRNA-mediated silencing or chemical inhibition impairs GSCs’ survival and self-renewal and most importantly, sensitizes these cells to IR. This newly uncovered role of RPA in GSCs supports its potential clinical significance as a druggable biomarker in GBM.
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27
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Kopa P, Macieja A, Galita G, Witczak ZJ, Poplawski T. DNA Double Strand Breaks Repair Inhibitors: Relevance as Potential New Anticancer Therapeutics. Curr Med Chem 2019; 26:1483-1493. [PMID: 29446719 DOI: 10.2174/0929867325666180214113154] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 01/22/2018] [Accepted: 01/23/2018] [Indexed: 12/19/2022]
Abstract
DNA double-strand breaks are considered one of the most lethal forms of DNA damage. Many effective anticancer therapeutic approaches used chemical and physical methods to generate DNA double-strand breaks in the cancer cells. They include: IR and drugs which mimetic its action, topoisomerase poisons, some alkylating agents or drugs which affected DNA replication process. On the other hand, cancer cells are mostly characterized by highly effective systems of DNA damage repair. There are two main DNA repair pathways used to fix double-strand breaks: NHEJ and HRR. Their activity leads to a decreased effect of chemotherapy. Targeting directly or indirectly the DNA double-strand breaks response by inhibitors seems to be an exciting option for anticancer therapy and is a part of novel trends that arise after the clinical success of PARP inhibitors. These trends will provide great opportunities for the development of DNA repair inhibitors as new potential anticancer drugs. The main objective of this article is to address these new promising advances.
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Affiliation(s)
- Paulina Kopa
- Department of Immunopathology, Faculty of Biomedical Sciences and Postgraduate Training, Medical University of Lodz, Lodz 90-752, Poland
| | - Anna Macieja
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz 90-236, Poland
| | - Grzegorz Galita
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz 90-236, Poland
| | - Zbigniew J Witczak
- Department of Pharmaceutical Sciences, Nesbitt School of Pharmacy, Wilkes University, Wilkes-Barre, PA 18766, United States
| | - Tomasz Poplawski
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz 90-236, Poland
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28
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Fortier E, Drobetsky E, Wurtele H. Know your limits: RPA availability and chemoresistance in ovarian cancer. Oncotarget 2019; 10:800-802. [PMID: 30783508 PMCID: PMC6368229 DOI: 10.18632/oncotarget.26607] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 01/13/2019] [Indexed: 11/28/2022] Open
Affiliation(s)
- Emile Fortier
- Centre de Recherche de l'Hôpital Maisonneuve-Rosemont, Montréal, Canada; Programme de Biologie Moléculaire, Université de Montréal, Montréal, Canada; Département de Médecine, Université de Montréal, Montréal, Canada
| | - Elliot Drobetsky
- Centre de Recherche de l'Hôpital Maisonneuve-Rosemont, Montréal, Canada; Programme de Biologie Moléculaire, Université de Montréal, Montréal, Canada; Département de Médecine, Université de Montréal, Montréal, Canada
| | - Hugo Wurtele
- Centre de Recherche de l'Hôpital Maisonneuve-Rosemont, Montréal, Canada; Programme de Biologie Moléculaire, Université de Montréal, Montréal, Canada; Département de Médecine, Université de Montréal, Montréal, Canada
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29
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Byrne BM, Oakley GG. Replication protein A, the laxative that keeps DNA regular: The importance of RPA phosphorylation in maintaining genome stability. Semin Cell Dev Biol 2018; 86:112-120. [PMID: 29665433 DOI: 10.1016/j.semcdb.2018.04.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/30/2018] [Accepted: 04/06/2018] [Indexed: 11/25/2022]
Abstract
The eukaryotic ssDNA-binding protein, Replication protein A (RPA), was first discovered almost three decades ago. Since then, much progress has been made to elucidate the critical roles for RPA in DNA metabolic pathways that help promote genomic stability. The canonical RPA heterotrimer (RPA1-3) is an essential coordinator of DNA metabolism that interacts with ssDNA and numerous protein partners to coordinate its roles in DNA replication, repair, recombination and telomere maintenance. An alternative form of RPA, termed aRPA, is formed by a complex of RPA4 with RPA1 and RPA3. aRPA is expressed differentially in cells compared to canonical RPA and has been shown to inhibit canonical RPA function while allowing for regular maintenance of cell viability. Interestingly, while aRPA is defective in DNA replication and cell cycle progression, it was shown to play a supporting role in nucleotide excision repair and recombination. The binding domains of canonical RPA interact with a growing number of partners involved in numerous genome maintenance processes. The protein interactions of the RPA-ssDNA complex are not only governed by competition between the binding proteins but also by post-translation modifications such as phosphorylation. Phosphorylation of RPA2 is an important post-translational modification of the RPA complex, and is essential for directing context-specific functions of the RPA complex in the DNA damage response. Due to the importance of RPA in cellular metabolism, it was identified as an appealing target for chemotherapeutic drug development that could be used in future cancer treatment regimens.
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Affiliation(s)
- Brendan M Byrne
- University of Nebraska Medical Center Department of Oral Biology, Lincoln NE, USA.
| | - Gregory G Oakley
- University of Nebraska Medical Center Department of Oral Biology, Lincoln NE, USA; Eppley Cancer Center, Omaha NE, USA.
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30
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In silico identification of inhibitors targeting N-Terminal domain of human Replication Protein A. J Mol Graph Model 2018; 86:149-159. [PMID: 30366191 DOI: 10.1016/j.jmgm.2018.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 12/29/2022]
Abstract
Replication Protein A (RPA) mediates DNA Damage Response (DDR) pathways through protein-protein interactions (PPIs). Targeting the PPIs formed between RPA and other DNA Damage Response (DDR) mediators has become an intriguing area of research for cancer drug discovery. A number of studies applied different methods ranging from high throughput screening approaches to fragment-based drug design tools to discover RPA inhibitors. Although these methods are robust, virtual screening approaches may be allocated as an alternative to such experimental methods, especially for screening of large libraries. Here we report the comprehensive screening of the large database, ZINC15 composed of ∼750 M compounds and the comparison of the identified ligands with the previously known inhibitors by means of binding affinity and drug-likeness. Initially, a ligand library sharing similarity with a promising inhibitor of the N-terminal domain of the RPA70 subunit (RPA70N) was generated by screening of the ZINC15 library. 46,999 ligands were collected and screened by LeDock which produced a satisfactory correlation with the experimental values (R2 = 0.77). 10 of the top-scoring ligands in LeDock were directly progressed to molecular dynamics (MD) simulations, while 10 additional ligands were also selected based on their LeDock scores and the presence of a functional group that could interact with the key amino acids in the RPA70N cleft. MD simulations were used to predict the binding free energy of the ligands by the MM-PBSA method which produced a high level of agreement with the experiments (R2 = 0.85). Binding free energy predictions pointed out 2 ligands with higher binding affinity than any of the reference inhibitors. Particularly the ligand ZINC000753854163 exhibited superior drug-likeness features than any of the known inhibitors. Overall, this study reports ZINC000753854163 as a possible inhibitor of RPA70N, reflecting its possible use in RPA70N targeted cancer therapy.
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Villa-Hernández S, Bermejo R. Replisome-Cohesin Interfacing: A Molecular Perspective. Bioessays 2018; 40:e1800109. [PMID: 30106480 DOI: 10.1002/bies.201800109] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/23/2018] [Indexed: 12/27/2022]
Abstract
Cohesion is established in S-phase through the action of key replisome factors as replication forks engage cohesin molecules. By holding sister chromatids together, cohesion critically assists both an equal segregation of the duplicated genetic material and an efficient repair of DNA breaks. Nonetheless, the molecular events leading the entrapment of nascent chromatids by cohesin during replication are only beginning to be understood. The authors describe here the essential structural features of the cohesin complex in connection to its ability to associate DNA molecules and review the current knowledge on the architectural-functional organization of the eukaryotic replisome, significantly advanced by recent biochemical and structural studies. In light of this novel insight, the authors discuss the mechanisms proposed to assist interfacing of replisomes with chromatin-bound cohesin complexes and elaborate on models for nascent chromatids entrapment by cohesin in the environment of the replication fork.
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Affiliation(s)
- Sara Villa-Hernández
- Centro de Investigaciones Biológicas (CIB-CSIC), Calle Ramiro de Maeztu 928040 Madrid, Spain
| | - Rodrigo Bermejo
- Centro de Investigaciones Biológicas (CIB-CSIC), Calle Ramiro de Maeztu 928040 Madrid, Spain
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32
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Yates M, Maréchal A. Ubiquitylation at the Fork: Making and Breaking Chains to Complete DNA Replication. Int J Mol Sci 2018; 19:E2909. [PMID: 30257459 PMCID: PMC6213728 DOI: 10.3390/ijms19102909] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 09/20/2018] [Accepted: 09/24/2018] [Indexed: 12/11/2022] Open
Abstract
The complete and accurate replication of the genome is a crucial aspect of cell proliferation that is often perturbed during oncogenesis. Replication stress arising from a variety of obstacles to replication fork progression and processivity is an important contributor to genome destabilization. Accordingly, cells mount a complex response to this stress that allows the stabilization and restart of stalled replication forks and enables the full duplication of the genetic material. This response articulates itself on three important platforms, Replication Protein A/RPA-coated single-stranded DNA, the DNA polymerase processivity clamp PCNA and the FANCD2/I Fanconi Anemia complex. On these platforms, the recruitment, activation and release of a variety of genome maintenance factors is regulated by post-translational modifications including mono- and poly-ubiquitylation. Here, we review recent insights into the control of replication fork stability and restart by the ubiquitin system during replication stress with a particular focus on human cells. We highlight the roles of E3 ubiquitin ligases, ubiquitin readers and deubiquitylases that provide the required flexibility at stalled forks to select the optimal restart pathways and rescue genome stability during stressful conditions.
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Affiliation(s)
- Maïlyn Yates
- Department of Biology, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.
| | - Alexandre Maréchal
- Department of Biology, Université de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada.
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33
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Zhang Z, Huo H, Liao K, Wang Z, Gong Z, Li Y, Liu C, Hu G. RPA1 downregulation enhances nasopharyngeal cancer radiosensitivity via blocking RAD51 to the DNA damage site. Exp Cell Res 2018; 371:330-341. [PMID: 30144445 DOI: 10.1016/j.yexcr.2018.08.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/01/2018] [Accepted: 08/21/2018] [Indexed: 12/25/2022]
Abstract
BACKGROUND/AIM Nasopharyngeal cancer (NPC) has a high local recurrence rate due to its resistance to ionizing radiation (IR). Replication protein A1 (RPA1) is one of the main elements in the homologous repair (HR) pathway, which is closely associated with the repair of DNA double strand breaks (DDBs). Studies on the relationship between RPA1 and the radiosensitivity of NPC are substantially limited. It was hypothesized that RPA1 plays a crucial role in predicting the radiosensitivity of NPC. METHODS The protein expression of RPA1 in 182 patients with NPC in the complete response (CR) and non-complete response (nCR) groups was evaluated using immunohistochemistry. Then, univariate and multivariate analysis were performed using SPSS software vision 22 to determine the relationship between the expression of RPA1 and the clinicopathological features. In addition, the mRNA expression of RPA1 was tested in 24 fresh samples using qRT-PCR. RPA1 was silenced in CNE-2R cell lines combined with IR to measure the radiosensitivity, proliferation, DNA damage repair and cell cycle of CNE-2R cells. Xenograft models in nude mice were used to determine the effect of RPA1 on tumor growth after IR. Immunoblotting and immunofluorescence staining were performed to identify proteins that interacted with RPA1. All statistical tests were two-sided. RESULTS RPA1 protein was overexpressed in NPC patients with nCR (65.31%), and was an independent predictor of radiosensitivity (HR: 3.755, 95% CI: 1.990-7.085), in addition to Epstein-Barr virus (EBV; HR: 3.984; 95% CI: 1.524-10.410). The silencing of RPA1 increased the radiosensitivity of CNE-2R cells, blocked the repair of DNA, impaired cell proliferation, and contributed to G2/M cell cycle arrest. Furthermore, the xenograft models in nude mice revealed that silencing RPA1 combined with irradiation significantly retarded the growth of tumors. Moreover, the knockdown of RPA1 decreased Rad51 collection to the damage site and prolonged the time of DNA repair. CONCLUSION RPA1 protein is frequently overexpressed in NPC patients with nCR. The silencing of RPA1 enhanced the radiosensitivity of CNE-2R cells. These present findings reveal that RPA1 is a potential biomarker for predicting the radiosensitivity in NPC.
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Affiliation(s)
- Zixin Zhang
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China; Department of Radiotherapy, the General Hospital of Ningxia Medical University, Yinchuan 750004, China
| | - Haifeng Huo
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Kui Liao
- Department of Oncology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Zhihai Wang
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Zhitao Gong
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Yanshi Li
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Chuan Liu
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Guohua Hu
- Department of Otorhinolaryngology, the First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
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Ng N, Purshouse K, Foskolou IP, Olcina MM, Hammond EM. Challenges to DNA replication in hypoxic conditions. FEBS J 2018; 285:1563-1571. [PMID: 29288533 DOI: 10.1111/febs.14377] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/05/2017] [Accepted: 12/22/2017] [Indexed: 12/30/2022]
Abstract
The term hypoxia refers to any condition where insufficient oxygen is available and therefore encompasses a range of actual oxygen concentrations. The regions of tumours adjacent to necrotic areas are at almost anoxic levels and are known to be extremely therapy resistant (radiobiological hypoxia). The biological response to radiobiological hypoxia includes the rapid accumulation of replication stress and subsequent DNA damage response, including both ATR- and ATM-mediated signalling, despite the absence of detectable DNA damage. The causes and consequences of hypoxia-induced replication stress will be discussed.
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Affiliation(s)
- Natalie Ng
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, UK
| | - Karin Purshouse
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, UK
| | - Iosifina P Foskolou
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, UK
| | - Monica M Olcina
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University, CA, USA
| | - Ester M Hammond
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, UK
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35
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Protein interactomes of protein phosphatase 2A B55 regulatory subunits reveal B55-mediated regulation of replication protein A under replication stress. Sci Rep 2018; 8:2683. [PMID: 29422626 PMCID: PMC5805732 DOI: 10.1038/s41598-018-21040-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 01/24/2018] [Indexed: 11/24/2022] Open
Abstract
The specific function of PP2A, a major serine/threonine phosphatase, is mediated by regulatory targeting subunits, such as members of the B55 family. Although implicated in cell division and other pathways, the specific substrates and functions of B55 targeting subunits are largely undefined. In this study we identified over 100 binding proteins of B55α and B55β in Xenopus egg extracts that are involved in metabolism, mitochondria function, molecular trafficking, cell division, cytoskeleton, DNA replication, DNA repair, and cell signaling. Among the B55α and B55β-associated proteins were numerous mitotic regulators, including many substrates of CDK1. Consistently, upregulation of B55α accelerated M-phase exit and inhibited M-phase entry. Moreover, specific substrates of CDK2, including factors of DNA replication and chromatin remodeling were identified within the interactomes of B55α and B55β, suggesting a role for these phosphatase subunits in DNA replication. In particular, we confirmed in human cells that B55α binds RPA and mediates the dephosphorylation of RPA2. The B55-RPA association is disrupted after replication stress, consistent with the induction of RPA2 phosphorylation. Thus, we report here a new mechanism that accounts for both how RPA phosphorylation is modulated by PP2A and how the phosphorylation of RPA2 is abruptly induced after replication stress.
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36
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MDM2 Antagonists Counteract Drug-Induced DNA Damage. EBioMedicine 2017; 24:43-55. [PMID: 29030058 PMCID: PMC5652019 DOI: 10.1016/j.ebiom.2017.09.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/12/2017] [Accepted: 09/14/2017] [Indexed: 12/16/2022] Open
Abstract
Antagonists of MDM2-p53 interaction are emerging anti-cancer drugs utilized in clinical trials for malignancies that rarely mutate p53, including melanoma. We discovered that MDM2-p53 antagonists protect DNA from drug-induced damage in melanoma cells and patient-derived xenografts. Among the tested DNA damaging drugs were various inhibitors of Aurora and Polo-like mitotic kinases, as well as traditional chemotherapy. Mitotic kinase inhibition causes mitotic slippage, DNA re-replication, and polyploidy. Here we show that re-replication of the polyploid genome generates replicative stress which leads to DNA damage. MDM2-p53 antagonists relieve replicative stress via the p53-dependent activation of p21 which inhibits DNA replication. Loss of p21 promoted drug-induced DNA damage in melanoma cells and enhanced anti-tumor activity of therapy combining MDM2 antagonist with mitotic kinase inhibitor in mice. In summary, MDM2 antagonists may reduce DNA damaging effects of anti-cancer drugs if they are administered together, while targeting p21 can improve the efficacy of such combinations.
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37
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Interactive Roles of DNA Helicases and Translocases with the Single-Stranded DNA Binding Protein RPA in Nucleic Acid Metabolism. Int J Mol Sci 2017; 18:ijms18061233. [PMID: 28594346 PMCID: PMC5486056 DOI: 10.3390/ijms18061233] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 05/30/2017] [Accepted: 06/01/2017] [Indexed: 01/05/2023] Open
Abstract
Helicases and translocases use the energy of nucleoside triphosphate binding and hydrolysis to unwind/resolve structured nucleic acids or move along a single-stranded or double-stranded polynucleotide chain, respectively. These molecular motors facilitate a variety of transactions including replication, DNA repair, recombination, and transcription. A key partner of eukaryotic DNA helicases/translocases is the single-stranded DNA binding protein Replication Protein A (RPA). Biochemical, genetic, and cell biological assays have demonstrated that RPA interacts with these human molecular motors physically and functionally, and their association is enriched in cells undergoing replication stress. The roles of DNA helicases/translocases are orchestrated with RPA in pathways of nucleic acid metabolism. RPA stimulates helicase-catalyzed DNA unwinding, enlists translocases to sites of action, and modulates their activities in DNA repair, fork remodeling, checkpoint activation, and telomere maintenance. The dynamic interplay between DNA helicases/translocases and RPA is just beginning to be understood at the molecular and cellular levels, and there is still much to be learned, which may inform potential therapeutic strategies.
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38
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Qu C, Zhao Y, Feng G, Chen C, Tao Y, Zhou S, Liu S, Chang H, Zeng M, Xia Y. RPA3 is a potential marker of prognosis and radioresistance for nasopharyngeal carcinoma. J Cell Mol Med 2017; 21:2872-2883. [PMID: 28557284 PMCID: PMC5661258 DOI: 10.1111/jcmm.13200] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 03/22/2017] [Indexed: 12/15/2022] Open
Abstract
Radioresistance-induced residual and recurrent tumours are the main cause of treatment failure in nasopharyngeal carcinoma (NPC). Thus, the mechanisms of NPC radioresistance and predictive markers of NPC prognosis and radioresistance need to be investigated and identified. In this study, we identified RPA3 as a candidate radioresistance marker using RNA-seq of NPC samples. In vitro studies further confirmed that RPA3 affected the radiosensitivity of NPC cells. Specifically, the overexpression of RPA3 enhanced radioresistance and the capacity for DNA repair of NPC cells, whereas inhibiting RPA3 expression sensitized NPC cells to irradiation and decreased the DNA repair capacity. Furthermore, the overexpression of RPA3 enhanced RAD51 foci formation in NPC cells after irradiation. Immunohistochemical assays in 104 NPC specimens and 21 normal epithelium specimens indicated that RPA3 was significantly up-regulated in NPC tissues, and a log-rank test suggested that in patients with NPC, high RPA3 expression was associated with shorter overall survival (OS) and a higher recurrence rate compared with low expression (5-year OS rates: 67.2% versus 86.2%; 5-year recurrence rates: 14.8% versus 2.3%). Moreover, TCGA data also indicated that high RPA3 expression correlated with poor OS and a high recurrence rate in patients with head and neck squamous cell carcinoma (HNSC) after radiotherapy. Taken together, the results of our study demonstrated that RPA3 regulated the radiosensitivity and DNA repair capacity of NPC cells. Thus, RPA3 may serve as a new predictive biomarker for NPC prognosis and radioresistance to help guide the diagnosis and individualized treatment of patients with NPC.
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Affiliation(s)
- Chen Qu
- Department of Radiation Oncology, Sun Yat-sen University Cancer Centre, Guangzhou, China.,State Key Laboratory of Oncology in South China, Guangzhou, China.,Collaborative Innovation Centre for Cancer Medicine, Guangzhou, China
| | - Yiying Zhao
- State Key Laboratory of Oncology in South China, Guangzhou, China.,Collaborative Innovation Centre for Cancer Medicine, Guangzhou, China.,Department of Experimental Research, Sun Yat-sen University Cancer Centre, Guangzhou, China
| | - Guokai Feng
- State Key Laboratory of Oncology in South China, Guangzhou, China.,Collaborative Innovation Centre for Cancer Medicine, Guangzhou, China.,Department of Experimental Research, Sun Yat-sen University Cancer Centre, Guangzhou, China
| | - Chen Chen
- Department of Radiation Oncology, Sun Yat-sen University Cancer Centre, Guangzhou, China.,State Key Laboratory of Oncology in South China, Guangzhou, China.,Collaborative Innovation Centre for Cancer Medicine, Guangzhou, China
| | - Yalan Tao
- Department of Radiation Oncology, Sun Yat-sen University Cancer Centre, Guangzhou, China.,State Key Laboratory of Oncology in South China, Guangzhou, China.,Collaborative Innovation Centre for Cancer Medicine, Guangzhou, China
| | - Shu Zhou
- Department of Radiation Oncology, Sun Yat-sen University Cancer Centre, Guangzhou, China.,State Key Laboratory of Oncology in South China, Guangzhou, China.,Collaborative Innovation Centre for Cancer Medicine, Guangzhou, China
| | - Songran Liu
- Department of Radiation Oncology, Sun Yat-sen University Cancer Centre, Guangzhou, China.,State Key Laboratory of Oncology in South China, Guangzhou, China.,Collaborative Innovation Centre for Cancer Medicine, Guangzhou, China
| | - Hui Chang
- Department of Radiation Oncology, Sun Yat-sen University Cancer Centre, Guangzhou, China.,State Key Laboratory of Oncology in South China, Guangzhou, China.,Collaborative Innovation Centre for Cancer Medicine, Guangzhou, China
| | - Musheng Zeng
- State Key Laboratory of Oncology in South China, Guangzhou, China.,Collaborative Innovation Centre for Cancer Medicine, Guangzhou, China.,Department of Experimental Research, Sun Yat-sen University Cancer Centre, Guangzhou, China
| | - Yunfei Xia
- Department of Radiation Oncology, Sun Yat-sen University Cancer Centre, Guangzhou, China.,State Key Laboratory of Oncology in South China, Guangzhou, China.,Collaborative Innovation Centre for Cancer Medicine, Guangzhou, China
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39
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Postigo A, Ramsden AE, Howell M, Way M. Cytoplasmic ATR Activation Promotes Vaccinia Virus Genome Replication. Cell Rep 2017; 19:1022-1032. [PMID: 28467896 PMCID: PMC5437729 DOI: 10.1016/j.celrep.2017.04.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 02/13/2017] [Accepted: 04/07/2017] [Indexed: 12/14/2022] Open
Abstract
In contrast to most DNA viruses, poxviruses replicate their genomes in the cytoplasm without host involvement. We find that vaccinia virus induces cytoplasmic activation of ATR early during infection, before genome uncoating, which is unexpected because ATR plays a fundamental nuclear role in maintaining host genome integrity. ATR, RPA, INTS7, and Chk1 are recruited to cytoplasmic DNA viral factories, suggesting canonical ATR pathway activation. Consistent with this, pharmacological and RNAi-mediated inhibition of canonical ATR signaling suppresses genome replication. RPA and the sliding clamp PCNA interact with the viral polymerase E9 and are required for DNA replication. Moreover, the ATR activator TOPBP1 promotes genome replication and associates with the viral replisome component H5. Our study suggests that, in contrast to long-held beliefs, vaccinia recruits conserved components of the eukaryote DNA replication and repair machinery to amplify its genome in the host cytoplasm.
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Affiliation(s)
- Antonio Postigo
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK
| | - Amy E Ramsden
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK
| | - Michael Howell
- High Throughput Screening Facility, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK
| | - Michael Way
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, 1 Midland Road, NW1 1AT London, UK.
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40
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Räschle M. Proteomics reveals a new DNA repair factor involved in DNA damage signaling. Mol Cell Oncol 2017; 4:e1263713. [PMID: 28197536 DOI: 10.1080/23723556.2016.1263713] [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: 11/11/2016] [Revised: 11/15/2016] [Accepted: 11/15/2016] [Indexed: 10/20/2022]
Abstract
Stalling of the DNA replication machinery activates the ATR checkpoint kinase, which coordinates the cellular responses to replication stress. New studies identify a novel ATR activator, ETAA1, which is indispensable for the maintenance of genome integrity. Dysregulation of ETAA1 may contribute to the development of pancreatic cancer.
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Affiliation(s)
- Markus Räschle
- Department of Molecular Genetics, TU Kaiserslautern , Kaiserslautern, Germany
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41
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Patrone JD, Waterson AG, Fesik SW. Recent advancements in the discovery of protein-protein interaction inhibitors of replication protein A. MEDCHEMCOMM 2017; 8:259-267. [PMID: 30108742 PMCID: PMC6071986 DOI: 10.1039/c6md00460a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/02/2016] [Indexed: 01/08/2023]
Abstract
Due to the relatively high rate of DNA damage that can occur during cell cycle progression, the DNA damage response (DDR) pathway is critical for the survival of eukaryotic cells. Replication protein A (RPA) is an essential cell cycle checkpoint protein that mediates the initiation of the DDR by binding to single-stranded DNA (ssDNA) and recruiting response partners via protein-protein interactions (PPIs). This important role of RPA in initiating the DDR and cell survival has led to interest within the scientific community to investigate RPA as a potential cancer drug discovery target. To this end, RPA inhibitors have been explored via a variety of methods. This review summarizes the structure and function of RPA and highlights recent efforts to discover inhibitors of RPA-protein interactions.
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Affiliation(s)
- James D Patrone
- Department of Chemistry , Rollins College , 1000 Holt Ave , Winter Park , FL 32789 , USA
| | - Alex G Waterson
- Department of Chemistry , Vanderbilt University , Nashville , TN 37232 , USA .
- Department of Pharmacology , Vanderbilt University School of Medicine , Nashville , TN 37232 , USA
| | - Stephen W Fesik
- Department of Chemistry , Vanderbilt University , Nashville , TN 37232 , USA .
- Department of Pharmacology , Vanderbilt University School of Medicine , Nashville , TN 37232 , USA
- Department of Biochemistry , Vanderbilt University School of Medicine , Nashville , TN 37232 , USA
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42
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Parsels LA, Tanska DM, Parsels JD, Zabludoff SD, Cuneo KC, Lawrence TS, Maybaum J, Morgan MA. Dissociation of gemcitabine chemosensitization by CHK1 inhibition from cell cycle checkpoint abrogation and aberrant mitotic entry. Cell Cycle 2016; 15:730-9. [PMID: 26890478 DOI: 10.1080/15384101.2016.1148841] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In order to determine the relative contribution of checkpoint abrogation and subsequent aberrant mitotic entry to gemcitabine chemosensitization by CHK1 inhibition, we established a model utilizing the CDK inhibitors roscovitine or purvalanol A to re-establish cell cycle arrest and prevent aberrant mitotic entry in pancreatic cancer cells treated with gemcitabine and the CHK inhibitor AZD7762. In this study, we report that the extent of aberrant mitotic entry, as determined by flow cytometry for the mitotic marker phospho-Histone H3 (Ser10), did not reflect the relative sensitivities of pancreatic cancer cell lines to gemcitabine chemosensitization by AZD7762. In addition, re-establishing gemcitabine-induced cell cycle arrest either pharmacologically, with roscovitine or purvalanol A, or genetically, with cyclin B1 siRNA, did not inhibit chemosensitization uniformly across the cell lines. Furthermore, we found that AZD7762 augmented high-intensity γH2AX signaling in gemcitabine-treated cells, suggesting the presence of replication stress when CHK1 is inhibited. Finally, the ability of roscovitine to prevent chemosensitization correlated with its ability to inhibit AZD7762-induced high-intensity γH2AX, but not aberrant pHH3, suggesting that the effects of AZD7762 on DNA replication or repair rather than aberrant mitotic entry determine gemcitabine chemosensitization in pancreatic cancer cells.
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Affiliation(s)
- Leslie A Parsels
- a Department of Radiation Oncology , University of Michigan Medical School , Ann Arbor , MI , USA.,b Department of Pharmacology , University of Michigan Medical School , Ann Arbor , MI , USA
| | - Daria M Tanska
- b Department of Pharmacology , University of Michigan Medical School , Ann Arbor , MI , USA
| | - Joshua D Parsels
- a Department of Radiation Oncology , University of Michigan Medical School , Ann Arbor , MI , USA.,b Department of Pharmacology , University of Michigan Medical School , Ann Arbor , MI , USA
| | - Sonya D Zabludoff
- c AstraZeneca R&D Boston , Waltham , MA , USA.,d Zabludoff Consulting San Diego , CA , USA
| | - Kyle C Cuneo
- a Department of Radiation Oncology , University of Michigan Medical School , Ann Arbor , MI , USA
| | - Theodore S Lawrence
- a Department of Radiation Oncology , University of Michigan Medical School , Ann Arbor , MI , USA
| | - Jonathan Maybaum
- a Department of Radiation Oncology , University of Michigan Medical School , Ann Arbor , MI , USA.,b Department of Pharmacology , University of Michigan Medical School , Ann Arbor , MI , USA
| | - Meredith A Morgan
- a Department of Radiation Oncology , University of Michigan Medical School , Ann Arbor , MI , USA
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43
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Glanzer JG, Endres JL, Byrne BM, Liu S, Bayles KW, Oakley GG. Identification of inhibitors for single-stranded DNA-binding proteins in eubacteria. J Antimicrob Chemother 2016; 71:3432-3440. [PMID: 27609050 DOI: 10.1093/jac/dkw340] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 06/17/2016] [Accepted: 07/19/2016] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES The increasing threat of drug-resistant bacteria establishes a continuing need for the development of new strategies to fight infection. We examine the inhibition of the essential single-stranded DNA-binding proteins (SSBs) SSBA and SSBB as a potential antimicrobial therapy due to their importance in DNA replication, activating the SOS response and promoting competence-based mechanisms of resistance by incorporating new DNA. METHODS Purified recombinant SSBs from Gram-positive (Staphylococcus aureus and Bacillus anthracis) and Gram-negative (Escherichia coli and Francisella tularensis) bacteria were assessed in a high-throughput screen for inhibition of duplex DNA unwinding by small molecule inhibitors. Secondary electrophoretic mobility shift assays further validated the top hits that were then tested for MICs using in vitro assays. RESULTS We have identified compounds that show cross-reactivity in vitro, as well as inhibition of both F. tularensis and B. anthracis SSBA. Five compounds were moderately toxic to at least two of the four bacterial strains in vivo, including two compounds that were selectively non-toxic to human cells, 9-hydroxyphenylfluoron and purpurogallin. Three of the SSBA inhibitors also inhibited S. aureus SSBB in Gram-positive bacteria. CONCLUSIONS Results from our study support the potential for SSB inhibitors as broad-spectrum antibacterial agents, with dual targeting capabilities against Gram-positive bacteria.
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Affiliation(s)
- Jason G Glanzer
- Department of Oral Biology, University of Nebraska Medical Center, Omaha, NE 68583, USA.,RPAcheQ, 16612 Martha Circle, Suite 510, Omaha, NE 68130, USA
| | - Jennifer L Endres
- Department of Pathology and Microbiology, University of Nebraska Medical Center, 986495 Nebraska Medical Center, Omaha, NE 68198-6495, USA
| | - Brendan M Byrne
- Department of Oral Biology, University of Nebraska Medical Center, Omaha, NE 68583, USA
| | - Shengqin Liu
- Department of Oral Biology, University of Nebraska Medical Center, Omaha, NE 68583, USA
| | - Kenneth W Bayles
- Department of Pathology and Microbiology, University of Nebraska Medical Center, 986495 Nebraska Medical Center, Omaha, NE 68198-6495, USA
| | - Greg G Oakley
- Department of Oral Biology, University of Nebraska Medical Center, Omaha, NE 68583, USA .,Eppley Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
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44
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Wu Y, Lu J, Kang T. Human single-stranded DNA binding proteins: guardians of genome stability. Acta Biochim Biophys Sin (Shanghai) 2016; 48:671-7. [PMID: 27217471 DOI: 10.1093/abbs/gmw044] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Accepted: 04/15/2016] [Indexed: 01/03/2023] Open
Abstract
Single-stranded DNA-binding proteins (SSBs) are essential for maintaining the integrity of the genome in all organisms. All processes related to DNA, such as replication, excision, repair, and recombination, require the participation of SSBs whose oligonucleotide/oligosaccharide-binding (OB)-fold domain is responsible for the interaction with single-stranded DNA (ssDNA). For a long time, the heterotrimeric replication protein A (RPA) complex was believed to be the only nuclear SSB in eukaryotes to participate in ssDNA processing, while mitochondrial SSBs that are conserved with prokaryotic SSBs were shown to be essential for maintaining genome stability in eukaryotic mitochondria. In recent years, two new proteins, hSSB1 and hSSB2 (human SSBs 1/2), were identified and have better sequence similarity to bacterial and archaeal SSBs than RPA. This review summarizes the current understanding of these human SSBs in DNA damage repair and in cell-cycle checkpoint activation following DNA damage, as well as their relationships with cancer.
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Affiliation(s)
- Yuanzhong Wu
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
| | - Jinping Lu
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
| | - Tiebang Kang
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
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45
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Patrone JD, Pelz NF, Bates BS, Souza-Fagundes EM, Vangamudi B, Camper DV, Kuznetsov AG, Browning CF, Feldkamp MD, Frank AO, Gilston BA, Olejniczak ET, Rossanese OW, Waterson AG, Chazin WJ, Fesik SW. Identification and Optimization of Anthranilic Acid Based Inhibitors of Replication Protein A. ChemMedChem 2016; 11:893-9. [PMID: 26748787 PMCID: PMC4838552 DOI: 10.1002/cmdc.201500479] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 12/08/2015] [Indexed: 01/19/2023]
Abstract
Replication protein A (RPA) is an essential single-stranded DNA (ssDNA)-binding protein that initiates the DNA damage response pathway through protein-protein interactions (PPIs) mediated by its 70N domain. The identification and use of chemical probes that can specifically disrupt these interactions is important for validating RPA as a cancer target. A high-throughput screen (HTS) to identify new chemical entities was conducted, and 90 hit compounds were identified. From these initial hits, an anthranilic acid based series was optimized by using a structure-guided iterative medicinal chemistry approach to yield a cell-penetrant compound that binds to RPA70N with an affinity of 812 nm. This compound, 2-(3- (N-(3,4-dichlorophenyl)sulfamoyl)-4-methylbenzamido)benzoic acid (20 c), is capable of inhibiting PPIs mediated by this domain.
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Affiliation(s)
- James D Patrone
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Chemistry, Rollins College, 1000 Holt Avenue, Winter Park, FL, 32789, USA
| | - Nicholas F Pelz
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Brittney S Bates
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | | | | | - Demarco V Camper
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Alexey G Kuznetsov
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Carrie F Browning
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Michael D Feldkamp
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Andreas O Frank
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Benjamin A Gilston
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Edward T Olejniczak
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Olivia W Rossanese
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Alex G Waterson
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Walter J Chazin
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37232, USA
| | - Stephen W Fesik
- Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232, USA.
- Department of Pharmacology, Vanderbilt University, Nashville, TN, 37232, USA.
- Department of Chemistry, Vanderbilt University, Nashville, TN, 37232, USA.
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46
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Morgan MA, Lawrence TS. Molecular Pathways: Overcoming Radiation Resistance by Targeting DNA Damage Response Pathways. Clin Cancer Res 2016; 21:2898-904. [PMID: 26133775 DOI: 10.1158/1078-0432.ccr-13-3229] [Citation(s) in RCA: 164] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
DNA double-strand breaks are the critical lesions responsible for the majority of ionizing radiation-induced cell killing. Thus, the ability of tumor cells to elicit a DNA damage response following radiation, via activation of DNA repair and cell-cycle checkpoints, promotes radiation resistance and tumor cell survival. Consequently, agents that target these DNA damage response pathways are being developed to overcome radiation resistance. Overall, these agents are effective radiosensitizers; however, their mechanisms of tumor cell selectivity are not fully elucidated. In this review, we focus on the crucial radiation-induced DNA damage responses as well as clinical and translational advances with agents designed to inhibit these responses. Importantly, we describe how synthetic lethality can provide tumor cell-selective radiosensitization by these agents and expand the therapeutic window for DNA damage response-targeted agents used in combination with radiotherapy.
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Affiliation(s)
- Meredith A Morgan
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan.
| | - Theodore S Lawrence
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan
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Desplancq D, Freund G, Conic S, Sibler AP, Didier P, Stoessel A, Oulad-Abdelghani M, Vigneron M, Wagner J, Mély Y, Chatton B, Tora L, Weiss E. Targeting the replisome with transduced monoclonal antibodies triggers lethal DNA replication stress in cancer cells. Exp Cell Res 2016; 342:145-58. [PMID: 26968636 DOI: 10.1016/j.yexcr.2016.03.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 02/29/2016] [Accepted: 03/06/2016] [Indexed: 12/21/2022]
Abstract
Although chemical inhibition of the DNA damage response (DDR) in cancer cells triggers cell death, it is not clear if the fork blockade achieved with inhibitors that neutralise proteins of the replisome is sufficient on its own to overcome the DDR. Monoclonal antibodies to PCNA, which block the DNA elongation process in vitro, have been developed. When these antibodies were transduced into cancer cells, they are able to inhibit the incorporation of nucleoside analogues. When co-delivered with anti-PCNA siRNA, the cells were flattened and the size of their nuclei increased by up to 3-fold, prior to cell death. Analysis of these nuclei by super-resolution microscopy revealed the presence of large numbers of phosphorylated histone H2AX foci. A senescence-like phenotype of the transduced cells was also observed upon delivery of the corresponding Fab molecules or following PCNA gene disruption or when the Fab fragment of an antibody that neutralises DNA polymerase alpha was used. Primary melanoma cells and leukaemia cells that are resistant to chemical inhibitors were similarly affected by these antibody treatments. These results demonstrate that transduced antibodies can trigger a lethal DNA replication stress, which kills cancer cells by abolishing the biological activity of several constituents of the replisome.
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Affiliation(s)
- Dominique Desplancq
- Ecole Supérieure de Biotechnologie de Strasbourg, UMR 7242, CNRS/Université de Strasbourg, boulevard Sébastien Brant, 67412 Illkirch, France
| | - Guillaume Freund
- Ecole Supérieure de Biotechnologie de Strasbourg, UMR 7242, CNRS/Université de Strasbourg, boulevard Sébastien Brant, 67412 Illkirch, France
| | - Sascha Conic
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, UMR 7104, CNRS/Université de Strasbourg, INSERM U964, rue Laurent Fries, 67404 Illkirch, France
| | - Annie-Paule Sibler
- Ecole Supérieure de Biotechnologie de Strasbourg, UMR 7242, CNRS/Université de Strasbourg, boulevard Sébastien Brant, 67412 Illkirch, France
| | - Pascal Didier
- Faculté de Pharmacie, UMR 7213, CNRS/Université de Strasbourg, route du Rhin, 67401 Illkirch, France
| | - Audrey Stoessel
- Ecole Supérieure de Biotechnologie de Strasbourg, UMR 7242, CNRS/Université de Strasbourg, boulevard Sébastien Brant, 67412 Illkirch, France
| | - Mustapha Oulad-Abdelghani
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, UMR 7104, CNRS/Université de Strasbourg, INSERM U964, rue Laurent Fries, 67404 Illkirch, France
| | - Marc Vigneron
- Ecole Supérieure de Biotechnologie de Strasbourg, UMR 7242, CNRS/Université de Strasbourg, boulevard Sébastien Brant, 67412 Illkirch, France
| | - Jérôme Wagner
- Ecole Supérieure de Biotechnologie de Strasbourg, UMR 7242, CNRS/Université de Strasbourg, boulevard Sébastien Brant, 67412 Illkirch, France
| | - Yves Mély
- Faculté de Pharmacie, UMR 7213, CNRS/Université de Strasbourg, route du Rhin, 67401 Illkirch, France
| | - Bruno Chatton
- Ecole Supérieure de Biotechnologie de Strasbourg, UMR 7242, CNRS/Université de Strasbourg, boulevard Sébastien Brant, 67412 Illkirch, France
| | - Laszlo Tora
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, UMR 7104, CNRS/Université de Strasbourg, INSERM U964, rue Laurent Fries, 67404 Illkirch, France
| | - Etienne Weiss
- Ecole Supérieure de Biotechnologie de Strasbourg, UMR 7242, CNRS/Université de Strasbourg, boulevard Sébastien Brant, 67412 Illkirch, France.
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Gavande NS, VanderVere-Carozza PS, Hinshaw HD, Jalal SI, Sears CR, Pawelczak KS, Turchi JJ. DNA repair targeted therapy: The past or future of cancer treatment? Pharmacol Ther 2016; 160:65-83. [PMID: 26896565 DOI: 10.1016/j.pharmthera.2016.02.003] [Citation(s) in RCA: 266] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The repair of DNA damage is a complex process that relies on particular pathways to remedy specific types of damage to DNA. The range of insults to DNA includes small, modest changes in structure including mismatched bases and simple methylation events to oxidized bases, intra- and interstrand DNA crosslinks, DNA double strand breaks and protein-DNA adducts. Pathways required for the repair of these lesions include mismatch repair, base excision repair, nucleotide excision repair, and the homology directed repair/Fanconi anemia pathway. Each of these pathways contributes to genetic stability, and mutations in genes encoding proteins involved in these pathways have been demonstrated to promote genetic instability and cancer. In fact, it has been suggested that all cancers display defects in DNA repair. It has also been demonstrated that the ability of cancer cells to repair therapeutically induced DNA damage impacts therapeutic efficacy. This has led to targeting DNA repair pathways and proteins to develop anti-cancer agents that will increase sensitivity to traditional chemotherapeutics. While initial studies languished and were plagued by a lack of specificity and a defined mechanism of action, more recent approaches to exploit synthetic lethal interaction and develop high affinity chemical inhibitors have proven considerably more effective. In this review we will highlight recent advances and discuss previous failures in targeting DNA repair to pave the way for future DNA repair targeted agents and their use in cancer therapy.
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Affiliation(s)
- Navnath S Gavande
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | | | - Hilary D Hinshaw
- Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Shadia I Jalal
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | - Catherine R Sears
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, United States
| | | | - John J Turchi
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, United States; NERx Biosciences, Indianapolis, IN 46202, United States; Department of Biochemistry & Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, United States.
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49
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Waterson AG, Kennedy JP, Patrone JD, Pelz NF, Feldkamp MD, Frank AO, Vangamudi B, Souza-Fagundes EM, Rossanese OW, Chazin WJ, Fesik SW. Diphenylpyrazoles as replication protein a inhibitors. ACS Med Chem Lett 2015; 6:140-5. [PMID: 25699140 DOI: 10.1021/ml5003629] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 11/11/2014] [Indexed: 01/16/2023] Open
Abstract
Replication Protein A is the primary eukaryotic ssDNA binding protein that has a central role in initiating the cellular response to DNA damage. RPA recruits multiple proteins to sites of DNA damage via the N-terminal domain of the 70 kDa subunit (RPA70N). Here we describe the optimization of a diphenylpyrazole carboxylic acid series of inhibitors of these RPA-protein interactions. We evaluated substituents on the aromatic rings as well as the type and geometry of the linkers used to combine fragments, ultimately leading to submicromolar inhibitors of RPA70N protein-protein interactions.
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Affiliation(s)
- Alex G. Waterson
- Department of Biochemistry, ‡Department of Pharmacology, Vanderbilt University School of
Medicine, and §Department of
Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - J. Phillip Kennedy
- Department of Biochemistry, ‡Department of Pharmacology, Vanderbilt University School of
Medicine, and §Department of
Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - James D. Patrone
- Department of Biochemistry, ‡Department of Pharmacology, Vanderbilt University School of
Medicine, and §Department of
Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Nicholas F. Pelz
- Department of Biochemistry, ‡Department of Pharmacology, Vanderbilt University School of
Medicine, and §Department of
Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Michael D. Feldkamp
- Department of Biochemistry, ‡Department of Pharmacology, Vanderbilt University School of
Medicine, and §Department of
Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Andreas O. Frank
- Department of Biochemistry, ‡Department of Pharmacology, Vanderbilt University School of
Medicine, and §Department of
Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Bhavatarini Vangamudi
- Department of Biochemistry, ‡Department of Pharmacology, Vanderbilt University School of
Medicine, and §Department of
Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Elaine M. Souza-Fagundes
- Department of Biochemistry, ‡Department of Pharmacology, Vanderbilt University School of
Medicine, and §Department of
Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Olivia W. Rossanese
- Department of Biochemistry, ‡Department of Pharmacology, Vanderbilt University School of
Medicine, and §Department of
Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Walter J. Chazin
- Department of Biochemistry, ‡Department of Pharmacology, Vanderbilt University School of
Medicine, and §Department of
Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Stephen W. Fesik
- Department of Biochemistry, ‡Department of Pharmacology, Vanderbilt University School of
Medicine, and §Department of
Chemistry, Vanderbilt University, Nashville, Tennessee 37232, United States
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