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Kutuk T, Atak E, Villa A, Kalman NS, Kaiser A. Interdisciplinary Collaboration in Head and Neck Cancer Care: Optimizing Oral Health Management for Patients Undergoing Radiation Therapy. Curr Oncol 2024; 31:2092-2108. [PMID: 38668058 PMCID: PMC11049200 DOI: 10.3390/curroncol31040155] [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: 01/12/2024] [Revised: 03/29/2024] [Accepted: 04/03/2024] [Indexed: 04/28/2024] Open
Abstract
Radiation therapy (RT) plays a crucial role in the treatment of head and neck cancers (HNCs). This paper emphasizes the importance of effective communication and collaboration between radiation oncologists and dental specialists in the HNC care pathway. It also provides an overview of the role of RT in HNC treatment and illustrates the interdisciplinary collaboration between these teams to optimize patient care, expedite treatment, and prevent post-treatment oral complications. The methods utilized include a thorough analysis of existing research articles, case reports, and clinical guidelines, with terms such as 'dental management', 'oral oncology', 'head and neck cancer', and 'radiotherapy' included for this review. The findings underscore the significance of the early involvement of dental specialists in the treatment planning phase to assess and prepare patients for RT, including strategies such as prophylactic tooth extraction to mitigate potential oral complications. Furthermore, post-treatment oral health follow-up and management by dental specialists are crucial in minimizing the incidence and severity of RT-induced oral sequelae. In conclusion, these proactive measures help minimize dental and oral complications before, during, and after treatment.
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Affiliation(s)
- Tugce Kutuk
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL 33176, USA; (T.K.)
| | - Ece Atak
- Department of Radiation Oncology, Akdeniz University Faculty of Medicine, Antalya 07070, Turkey;
| | - Alessandro Villa
- Oral Medicine and Oral Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL 33176, USA;
| | - Noah S. Kalman
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL 33176, USA; (T.K.)
- Department of Radiation Oncology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, USA
| | - Adeel Kaiser
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL 33176, USA; (T.K.)
- Department of Radiation Oncology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, USA
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2
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Marttila P, Bonagas N, Chalkiadaki C, Stigsdotter H, Schelzig K, Shen J, Farhat CM, Hondema A, Albers J, Wiita E, Rasti A, Warpman Berglund U, Slipicevic A, Mortusewicz O, Helleday T. The one-carbon metabolic enzyme MTHFD2 promotes resection and homologous recombination after ionizing radiation. Mol Oncol 2024. [PMID: 38533616 DOI: 10.1002/1878-0261.13645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 02/23/2024] [Accepted: 03/18/2024] [Indexed: 03/28/2024] Open
Abstract
The one-carbon metabolism enzyme bifunctional methylenetetrahydrofolate dehydrogenase/cyclohydrolase 2 (MTHFD2) is among the most overexpressed proteins across tumors and is widely recognized as a promising anticancer target. While MTHFD2 is mainly described as a mitochondrial protein, a new nuclear function is emerging. Here, we observe that nuclear MTHFD2 protein levels and association with chromatin increase following ionizing radiation (IR) in an ataxia telangiectasia mutated (ATM)- and DNA-dependent protein kinase (DNA-PK)-dependent manner. Furthermore, repair of IR-induced DNA double-strand breaks (DSBs) is delayed upon MTHFD2 knockdown, suggesting a role for MTHFD2 in DSB repair. In support of this, we observe impaired recruitment of replication protein A (RPA), reduced resection, decreased IR-induced DNA repair protein RAD51 homolog 1 (RAD51) levels and impaired homologous recombination (HR) activity in MTHFD2-depleted cells following IR. In conclusion, we identify a key role for MTHFD2 in HR repair and describe an interdependency between MTHFD2 and HR proficiency that could potentially be exploited for cancer therapy.
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Affiliation(s)
- Petra Marttila
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Nadilly Bonagas
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Christina Chalkiadaki
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Hannah Stigsdotter
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Korbinian Schelzig
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Jianyu Shen
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Crystal M Farhat
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Amber Hondema
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Julian Albers
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Elisée Wiita
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Azita Rasti
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Ulrika Warpman Berglund
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Ana Slipicevic
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
- One-carbon Therapeutics AB, Stockholm, Sweden
| | - Oliver Mortusewicz
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
| | - Thomas Helleday
- Science for Life Laboratory, Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden
- Weston Park Cancer Centre, Department of Oncology and Metabolism, The Medical School, University of Sheffield, UK
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3
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Coll RP, Bright SJ, Martinus DKJ, Georgiou DK, Sawakuchi GO, Manning HC. Alpha Particle-Emitting Radiopharmaceuticals as Cancer Therapy: Biological Basis, Current Status, and Future Outlook for Therapeutics Discovery. Mol Imaging Biol 2023; 25:991-1019. [PMID: 37845582 DOI: 10.1007/s11307-023-01857-y] [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: 06/26/2023] [Revised: 09/03/2023] [Accepted: 09/05/2023] [Indexed: 10/18/2023]
Abstract
Critical advances in radionuclide therapy have led to encouraging new options for cancer treatment through the pairing of clinically useful radiation-emitting radionuclides and innovative pharmaceutical discovery. Of the various subatomic particles used in therapeutic radiopharmaceuticals, alpha (α) particles show great promise owing to their relatively large size, delivered energy, finite pathlength, and resulting ionization density. This review discusses the therapeutic benefits of α-emitting radiopharmaceuticals and their pairing with appropriate diagnostics, resulting in innovative "theranostic" platforms. Herein, the current landscape of α particle-emitting radionuclides is described with an emphasis on their use in theranostic development for cancer treatment. Commonly studied radionuclides are introduced and recent efforts towards their production for research and clinical use are described. The growing popularity of these radionuclides is explained through summarizing the biological effects of α radiation on cancer cells, which include DNA damage, activation of discrete cell death programs, and downstream immune responses. Examples of efficient α-theranostic design are described with an emphasis on strategies that lead to cellular internalization and the targeting of proteins involved in therapeutic resistance. Historical barriers to the clinical deployment of α-theranostic radiopharmaceuticals are also discussed. Recent progress towards addressing these challenges is presented along with examples of incorporating α-particle therapy in pharmaceutical platforms that can be easily converted into diagnostic counterparts.
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Affiliation(s)
- Ryan P Coll
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, 1881 East Rd, Houston, TX, 77054, USA
| | - Scott J Bright
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 6565 MD Anderson Blvd, Houston, TX, 77030, USA
| | - David K J Martinus
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 6565 MD Anderson Blvd, Houston, TX, 77030, USA
| | - Dimitra K Georgiou
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, 1881 East Rd, Houston, TX, 77054, USA
| | - Gabriel O Sawakuchi
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 6565 MD Anderson Blvd, Houston, TX, 77030, USA
| | - H Charles Manning
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, 1881 East Rd, Houston, TX, 77054, USA.
- Cyclotron Radiochemistry Facility, The University of Texas MD Anderson Cancer Center, 1881 East Rd, Houston, TX, 77054, USA.
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4
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Liao H, Yang S, Liang Z, Xiao L, Xie S, Lin P, Xia F, Fang C, Chen Q, Ling D, Li F. A Cancer Cell Selective Replication Stress Nano Amplifier Promotes Replication Fork Catastrophe to Overcome Radioresistance. ACS NANO 2023; 17:18548-18561. [PMID: 37706454 DOI: 10.1021/acsnano.3c06774] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
Replication stress (RS) induced by DNA damage plays a significant role in conferring the anticancer effects of radiotherapy and is tightly associated with radioresistance of cancer cells. Amplification of RS represents an effective approach to improving the efficacy of radiotherapy, although the development of selective RS amplifiers remains an unexplored frontier. We herein present an RS nano amplifier (RSNA) consisting of a catalytic FePt nanoparticle loaded with the chemotherapeutic doxorubicin (DOX), which selectively exacerbates RS in cancer cells by promoting replication fork (RF) catastrophe. RSNA converts the excessive reactive oxygen species (ROS) in cancer cells into oxygen, enhancing the DNA-damaging effects of radiotherapy to create more template lesions that impede RF progression in coalition with DOX. After radiation, ROS scavenging by RSNA accelerates RF progression through damaged template strands, increasing the frequency of RF collapse into double-strand breaks. Moreover, pretreatment with RSNA accumulates cancer cells in the S phase, exposing more RFs to radiation-induced RS. These effects of RSNA convergently maximize RS in cancer cells, effectively overcoming the radioresistance of cancer cells without affecting normal cells. Our study demonstrates the feasibility of selectively amplifying RS to boost radiotherapy.
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Affiliation(s)
- Hongwei Liao
- Institute of Pharmaceutics, Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shengfei Yang
- Institute of Pharmaceutics, Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Zeyu Liang
- Institute of Pharmaceutics, Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lin Xiao
- Institute of Pharmaceutics, Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shangzhi Xie
- Institute of Pharmaceutics, Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Peihua Lin
- Institute of Pharmaceutics, Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Fan Xia
- Institute of Pharmaceutics, Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Chunyan Fang
- Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qian Chen
- Institute of Pharmaceutics, Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Daishun Ling
- Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, National Center for Translational Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
- WLA Laboratories, Shanghai 201203, China
| | - Fangyuan Li
- Institute of Pharmaceutics, Hangzhou Institute of Innovative Medicine, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
- WLA Laboratories, Shanghai 201203, China
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5
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Ohuchi K, Saga R, Hasegawa K, Tsuruga E, Hosokawa Y, Fukumoto M, Okumura K. DNA‑PKcs phosphorylation specific inhibitor, NU7441, enhances the radiosensitivity of clinically relevant radioresistant oral squamous cell carcinoma cells. Biomed Rep 2023; 18:28. [PMID: 36926187 PMCID: PMC10011949 DOI: 10.3892/br.2023.1610] [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: 10/20/2022] [Accepted: 01/23/2023] [Indexed: 02/26/2023] Open
Abstract
Radioresistant cancer cells lead to poor prognosis after radiotherapy. However, the mechanisms underlying cancer cell radioresistance have not been fully elucidated. Thus, the DNA damage response of clinically relevant radioresistant oral squamous cell carcinoma HSC2-R cells, established by long-term exposure of parental HSC2 cells to fractionated radiation, was investigated. The DNA double-strand break (DSB) repair protein-specific inhibitor, NU7441, which targets DNA-dependent protein kinase catalytic subunit (DNA-PKcs) phosphorylation, and IBR2, which targets Rad51, were administered to HSC2 and HSC2-R cells. NU7441 administration eliminated colony formation in both cell lines under 6 Gy X-ray irradiation, whereas IBR2 did not affect colony formation. NU7441 and IBR2 significantly enhanced 6 Gy X-ray irradiation-induced apoptosis in HSC2-R cells. In HSC2-R cells, cell cycle arrest released earlier than in HSC2 cells, and phosphorylated-H2A histone family member X (γH2AX) expression rapidly decreased. Following NU7441 administration, γH2AX expression and the cell percentages of the G2/M phase were not decreased at 48 h after treatment in HSC2-R cells. DNA-PKcs has been demonstrated to regulate non-homologous end-joining (NHEJ) and homologous recombination (HR) repair, and the later phase of DSB repair is dominated by HR. Therefore, the results of the present study indicated that the DSB repair mechanism in HSC2-R cells strongly depends on NHEJ and loss of HR repair function. The present study revealed a potential mechanism underlying the acquired radioresistance and therapeutic targets in radioresistant cancer cells.
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Affiliation(s)
- Kentaro Ohuchi
- Division of Reconstructive Surgery for Oral and Maxillofacial Region, Department of Human Biology and Pathophysiology, School of Dentistry, Health Sciences University of Hokkaido, Tobetsu-cho, Ishikari-gun, Hokkaido 061-0293, Japan
| | - Ryo Saga
- Department of Radiation Science, Graduate School of Health Sciences, Hirosaki University, Hirosaki, Aomori 036-8564, Japan
| | - Kazuki Hasegawa
- Department of Radiation Science, Graduate School of Health Sciences, Hirosaki University, Hirosaki, Aomori 036-8564, Japan
| | - Eichi Tsuruga
- Department of Radiation Science, Graduate School of Health Sciences, Hirosaki University, Hirosaki, Aomori 036-8564, Japan
| | - Yoichiro Hosokawa
- Department of Radiation Science, Graduate School of Health Sciences, Hirosaki University, Hirosaki, Aomori 036-8564, Japan
| | - Manabu Fukumoto
- Pathology Informatics Team, RIKEN Center for Advanced Intelligence Project, Chuo-ku, Tokyo 103-0027, Japan
| | - Kazuhiko Okumura
- Division of Reconstructive Surgery for Oral and Maxillofacial Region, Department of Human Biology and Pathophysiology, School of Dentistry, Health Sciences University of Hokkaido, Tobetsu-cho, Ishikari-gun, Hokkaido 061-0293, Japan
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6
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Soni A, Lin X, Mladenov E, Mladenova V, Stuschke M, Iliakis G. BMN673 Is a PARP Inhibitor with Unique Radiosensitizing Properties: Mechanisms and Potential in Radiation Therapy. Cancers (Basel) 2022; 14:cancers14225619. [PMID: 36428712 PMCID: PMC9688666 DOI: 10.3390/cancers14225619] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/10/2022] [Accepted: 11/13/2022] [Indexed: 11/17/2022] Open
Abstract
BMN673 is a relatively new PARP inhibitor (PARPi) that exhibits superior efficacy in vitro compared to olaparib and other clinically relevant PARPi. BMN673, similar to most clinical PARPi, inhibits the catalytic activities of PARP-1 and PARP-2 and shows impressive anticancer potential as monotherapy in several pre-clinical and clinical studies. Tumor resistance to PARPi poses a significant challenge in the clinic. Thus, combining PARPi with other treatment modalities, such as radiotherapy (RT), is being actively pursued to overcome such resistance. However, the modest to intermediate radiosensitization exerted by olaparib, rucaparib, and veliparib, limits the rationale and the scope of such combinations. The recently reported strong radiosensitizing potential of BMN673 forecasts a paradigm shift on this front. Evidence accumulates that BMN673 may radiosensitize via unique mechanisms causing profound shifts in the balance among DNA double-strand break (DSB) repair pathways. According to one of the emerging models, BMN673 strongly inhibits classical non-homologous end-joining (c-NHEJ) and increases reciprocally and profoundly DSB end-resection, enhancing error-prone DSB processing that robustly potentiates cell killing. In this review, we outline and summarize the work that helped to formulate this model of BMN673 action on DSB repair, analyze the causes of radiosensitization and discuss its potential as a radiosensitizer in the clinic. Finally, we highlight strategies for combining BMN673 with other inhibitors of DNA damage response for further improvements.
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Affiliation(s)
- Aashish Soni
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Xixi Lin
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Emil Mladenov
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Veronika Mladenova
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Martin Stuschke
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, German Cancer Research Center (DKFZ), 45147 Essen, Germany
| | - George Iliakis
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Correspondence: ; Tel.: +49-201-723-4152
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7
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Camero S, Cassandri M, Pomella S, Milazzo L, Vulcano F, Porrazzo A, Barillari G, Marchese C, Codenotti S, Tomaciello M, Rota R, Fanzani A, Megiorni F, Marampon F. Radioresistance in rhabdomyosarcomas: Much more than a question of dose. Front Oncol 2022; 12:1016894. [PMID: 36248991 PMCID: PMC9559533 DOI: 10.3389/fonc.2022.1016894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 09/12/2022] [Indexed: 11/15/2022] Open
Abstract
Management of rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children, frequently accounting the genitourinary tract is complex and requires a multimodal therapy. In particular, as a consequence of the advancement in dose conformity technology, radiation therapy (RT) has now become the standard therapeutic option for patients with RMS. In the clinical practice, dose and timing of RT are adjusted on the basis of patients' risk stratification to reduce late toxicity and side effects on normal tissues. However, despite the substantial improvement in cure rates, local failure and recurrence frequently occur. In this review, we summarize the general principles of the treatment of RMS, focusing on RT, and the main molecular pathways and specific proteins involved into radioresistance in RMS tumors. Specifically, we focused on DNA damage/repair, reactive oxygen species, cancer stem cells, and epigenetic modifications that have been reported in the context of RMS neoplasia in both in vitro and in vivo studies. The precise elucidation of the radioresistance-related molecular mechanisms is of pivotal importance to set up new more effective and tolerable combined therapeutic approaches that can radiosensitize cancer cells to finally ameliorate the overall survival of patients with RMS, especially for the most aggressive subtypes.
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Affiliation(s)
- Simona Camero
- Department of Maternal, Infantile and Urological Sciences, Sapienza University of Rome, Rome, Italy
| | - Matteo Cassandri
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Rome, Italy
- Department of Oncohematology, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Silvia Pomella
- Department of Oncohematology, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Luisa Milazzo
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Francesca Vulcano
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Antonella Porrazzo
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Rome, Italy
- Units of Molecular Genetics of Complex Phenotypes, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCSS), Rome, Italy
| | - Giovanni Barillari
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Cinzia Marchese
- Department of Experimental Medicine, “Sapienza” University of Rome, Rome, Italy
| | - Silvia Codenotti
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Miriam Tomaciello
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Rome, Italy
| | - Rossella Rota
- Department of Oncohematology, Bambino Gesù Children’s Hospital, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Alessandro Fanzani
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Francesca Megiorni
- Department of Experimental Medicine, “Sapienza” University of Rome, Rome, Italy
| | - Francesco Marampon
- Department of Radiological Sciences, Oncology and Anatomical Pathology, Sapienza University of Rome, Rome, Italy
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8
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Nickoloff JA. Targeting Replication Stress Response Pathways to Enhance Genotoxic Chemo- and Radiotherapy. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27154736. [PMID: 35897913 PMCID: PMC9330692 DOI: 10.3390/molecules27154736] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 12/12/2022]
Abstract
Proliferating cells regularly experience replication stress caused by spontaneous DNA damage that results from endogenous reactive oxygen species (ROS), DNA sequences that can assume secondary and tertiary structures, and collisions between opposing transcription and replication machineries. Cancer cells face additional replication stress, including oncogenic stress that results from the dysregulation of fork progression and origin firing, and from DNA damage induced by radiotherapy and most cancer chemotherapeutic agents. Cells respond to such stress by activating a complex network of sensor, signaling and effector pathways that protect genome integrity. These responses include slowing or stopping active replication forks, protecting stalled replication forks from collapse, preventing late origin replication firing, stimulating DNA repair pathways that promote the repair and restart of stalled or collapsed replication forks, and activating dormant origins to rescue adjacent stressed forks. Currently, most cancer patients are treated with genotoxic chemotherapeutics and/or ionizing radiation, and cancer cells can gain resistance to the resulting replication stress by activating pro-survival replication stress pathways. Thus, there has been substantial effort to develop small molecule inhibitors of key replication stress proteins to enhance tumor cell killing by these agents. Replication stress targets include ATR, the master kinase that regulates both normal replication and replication stress responses; the downstream signaling kinase Chk1; nucleases that process stressed replication forks (MUS81, EEPD1, Metnase); the homologous recombination catalyst RAD51; and other factors including ATM, DNA-PKcs, and PARP1. This review provides an overview of replication stress response pathways and discusses recent pre-clinical studies and clinical trials aimed at improving cancer therapy by targeting replication stress response factors.
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Affiliation(s)
- Jac A Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA
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9
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Krayem M, Ghanem GE, Van Gestel D. Recent advances in radiosensitivity determinants in melanoma. Curr Opin Oncol 2022; 34:131-138. [PMID: 35013044 DOI: 10.1097/cco.0000000000000818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Radiotherapy has been proven to be useful but insufficient in melanoma management due to the intrinsic radioresistance of melanoma cells. Elucidation of the molecular mechanisms and pathways related to resistance/sensitivity to radiotherapy in melanoma is of paramount importance. In this review, we will summarize and discuss the recent 'discoveries' and advances in radiosensitivity determinants in melanoma. RECENT FINDINGS The different levels of radiosensitivity among the various melanoma tumors could be attributed to the DNA damage signaling and repair proteins, tumor microenvironment, hypoxia, cell metabolism, glutathione and redox balance, protein kinase signaling pathways as well as pigmentation and melanin content. SUMMARY It is therapeutically important to elucidate the factors involved in radiation resistance/sensitivity of melanoma. More importantly, improving radiosensitivity may 'widen the clinical utility' in melanoma of this important therapeutic modality.
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Affiliation(s)
- Mohammad Krayem
- Laboratory of Clinical and Experimental Oncology (LOCE), Institut Jules Bordet
- Department of Radiation Oncology, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - Ghanem E Ghanem
- Laboratory of Clinical and Experimental Oncology (LOCE), Institut Jules Bordet
| | - Dirk Van Gestel
- Department of Radiation Oncology, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
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10
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Parsels LA, Zhang Q, Karnak D, Parsels JD, Lam K, Willers H, Green MD, Rehemtulla A, Lawrence TS, Morgan MA. Translation of DNA Damage Response Inhibitors as Chemoradiation Sensitizers From the Laboratory to the Clinic. Int J Radiat Oncol Biol Phys 2021; 111:e38-e53. [PMID: 34348175 PMCID: PMC8602768 DOI: 10.1016/j.ijrobp.2021.07.1708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 07/23/2021] [Indexed: 12/25/2022]
Abstract
Combination therapies with agents targeting the DNA damage response (DDR) offer an opportunity to selectively enhance the therapeutic index of chemoradiation or eliminate use of chemotherapy altogether. The successful translation of DDR inhibitors to clinical use requires investigating both their direct actions as (chemo)radiosensitizers and their potential to stimulate tumor immunogenicity. Beginning with high-throughput screening using both viability and DNA damage-reporter assays, followed by validation in gold-standard radiation colony-forming assays and in vitro assessment of mechanistic effects on the DDR, we describe proven strategies and methods leading to the clinical development of DDR inhibitors both with radiation alone and in combination with chemoradiation. Beyond these in vitro studies, we discuss the impact of key features of human xenograft and syngeneic mouse models on the relevance of in vivo tumor efficacy studies, particularly with regard to the immunogenic effects of combined therapy with radiation and DDR inhibitors. Finally, we describe recent technological advances in radiation delivery (using the small animal radiation research platform) that allow for conformal, clinically relevant radiation therapy in mouse models. This overall approach is critical to the successful clinical development and ultimate Food and Drug Administration approval of DDR inhibitors as (chemo)radiation sensitizers.
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Affiliation(s)
- Leslie A Parsels
- Department of Radiation Oncology, University of Michigan Medical School and Rogel Cancer Center, Ann Arbor, Michigan
| | - Qiang Zhang
- Department of Radiation Oncology, University of Michigan Medical School and Rogel Cancer Center, Ann Arbor, Michigan
| | - David Karnak
- Department of Radiation Oncology, University of Michigan Medical School and Rogel Cancer Center, Ann Arbor, Michigan
| | - Joshua D Parsels
- Department of Radiation Oncology, University of Michigan Medical School and Rogel Cancer Center, Ann Arbor, Michigan
| | - Kwok Lam
- Department of Radiation Oncology, University of Michigan Medical School and Rogel Cancer Center, Ann Arbor, Michigan
| | - Henning Willers
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Michael D Green
- Department of Radiation Oncology, University of Michigan Medical School and Rogel Cancer Center, Ann Arbor, Michigan
| | - Alnawaz Rehemtulla
- Department of Radiation Oncology, University of Michigan Medical School and Rogel Cancer Center, Ann Arbor, Michigan
| | - Theodore S Lawrence
- Department of Radiation Oncology, University of Michigan Medical School and Rogel Cancer Center, Ann Arbor, Michigan
| | - Meredith A Morgan
- Department of Radiation Oncology, University of Michigan Medical School and Rogel Cancer Center, Ann Arbor, Michigan.
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11
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Nickoloff JA, Sharma N, Allen CP, Taylor L, Allen SJ, Jaiswal AS, Hromas R. Roles of homologous recombination in response to ionizing radiation-induced DNA damage. Int J Radiat Biol 2021; 99:903-914. [PMID: 34283012 PMCID: PMC9629169 DOI: 10.1080/09553002.2021.1956001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/04/2021] [Accepted: 07/05/2021] [Indexed: 02/06/2023]
Abstract
PURPOSE Ionizing radiation induces a vast array of DNA lesions including base damage, and single- and double-strand breaks (SSB, DSB). DSBs are among the most cytotoxic lesions, and mis-repair causes small- and large-scale genome alterations that can contribute to carcinogenesis. Indeed, ionizing radiation is a 'complete' carcinogen. DSBs arise immediately after irradiation, termed 'frank DSBs,' as well as several hours later in a replication-dependent manner, termed 'secondary' or 'replication-dependent DSBs. DSBs resulting from replication fork collapse are single-ended and thus pose a distinct problem from two-ended, frank DSBs. DSBs are repaired by error-prone nonhomologous end-joining (NHEJ), or generally error-free homologous recombination (HR), each with sub-pathways. Clarifying how these pathways operate in normal and tumor cells is critical to increasing tumor control and minimizing side effects during radiotherapy. CONCLUSIONS The choice between NHEJ and HR is regulated during the cell cycle and by other factors. DSB repair pathways are major contributors to cell survival after ionizing radiation, including tumor-resistance to radiotherapy. Several nucleases are important for HR-mediated repair of replication-dependent DSBs and thus replication fork restart. These include three structure-specific nucleases, the 3' MUS81 nuclease, and two 5' nucleases, EEPD1 and Metnase, as well as three end-resection nucleases, MRE11, EXO1, and DNA2. The three structure-specific nucleases evolved at very different times, suggesting incremental acceleration of replication fork restart to limit toxic HR intermediates and genome instability as genomes increased in size during evolution, including the gain of large numbers of HR-prone repetitive elements. Ionizing radiation also induces delayed effects, observed days to weeks after exposure, including delayed cell death and delayed HR. In this review we highlight the roles of HR in cellular responses to ionizing radiation, and discuss the importance of HR as an exploitable target for cancer radiotherapy.
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Affiliation(s)
- Jac A. Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
| | - Neelam Sharma
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
| | - Christopher P. Allen
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
- Department of Microbiology, Immunology and Pathology, Flow Cytometry and Cell Sorting Facility, Colorado State University, Fort Collins, CO, USA
| | - Lynn Taylor
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
| | - Sage J. Allen
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
| | - Aruna S. Jaiswal
- Division of Hematology and Medical Oncology, Department of Medicine and the Mays Cancer Center, University of Texas Health Science Center, San Antonio, TX, 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, USA
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12
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Herbert KJ, Puliyadi R, Prevo R, Rodriguez-Berriguete G, Ryan A, Ramadan K, Higgins GS. Targeting TOPK sensitises tumour cells to radiation-induced damage by enhancing replication stress. Cell Death Differ 2021; 28:1333-1346. [PMID: 33168956 PMCID: PMC8027845 DOI: 10.1038/s41418-020-00655-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 10/22/2020] [Accepted: 10/22/2020] [Indexed: 01/04/2023] Open
Abstract
T-LAK-originated protein kinase (TOPK) overexpression is a feature of multiple cancers, yet is absent from most phenotypically normal tissues. As such, TOPK expression profiling and the development of TOPK-targeting pharmaceutical agents have raised hopes for its future potential in the development of targeted therapeutics. Results presented in this paper confirm the value of TOPK as a potential target for the treatment of solid tumours, and demonstrate the efficacy of a TOPK inhibitor (OTS964) when used in combination with radiation treatment. Using H460 and Calu-6 lung cancer xenograft models, we show that pharmaceutical inhibition of TOPK potentiates the efficacy of fractionated irradiation. Furthermore, we provide in vitro evidence that TOPK plays a hitherto unknown role during S phase, showing that TOPK depletion increases fork stalling and collapse under conditions of replication stress and exogenous DNA damage. Transient knockdown of TOPK was shown to impair recovery from fork stalling and to increase the formation of replication-associated single-stranded DNA foci in H460 lung cancer cells. We also show that TOPK interacts directly with CHK1 and Cdc25c, two key players in the checkpoint signalling pathway activated after replication fork collapse. This study thus provides novel insights into the mechanism by which TOPK activity supports the survival of cancer cells, facilitating checkpoint signalling in response to replication stress and DNA damage.
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Affiliation(s)
- Katharine J Herbert
- MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Rathi Puliyadi
- MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Remko Prevo
- MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Gonzalo Rodriguez-Berriguete
- MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Anderson Ryan
- MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Kristijan Ramadan
- MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Geoff S Higgins
- MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK.
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13
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Hausmann M, Falk M, Neitzel C, Hofmann A, Biswas A, Gier T, Falkova I, Heermann DW, Hildenbrand G. Elucidation of the Clustered Nano-Architecture of Radiation-Induced DNA Damage Sites and Surrounding Chromatin in Cancer Cells: A Single Molecule Localization Microscopy Approach. Int J Mol Sci 2021; 22:3636. [PMID: 33807337 PMCID: PMC8037797 DOI: 10.3390/ijms22073636] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/20/2021] [Accepted: 03/26/2021] [Indexed: 02/06/2023] Open
Abstract
In cancer therapy, the application of (fractionated) harsh radiation treatment is state of the art for many types of tumors. However, ionizing radiation is a "double-edged sword"-it can kill the tumor but can also promote the selection of radioresistant tumor cell clones or even initiate carcinogenesis in the normal irradiated tissue. Individualized radiotherapy would reduce these risks and boost the treatment, but its development requires a deep understanding of DNA damage and repair processes and the corresponding control mechanisms. DNA double strand breaks (DSBs) and their repair play a critical role in the cellular response to radiation. In previous years, it has become apparent that, beyond genetic and epigenetic determinants, the structural aspects of damaged chromatin (i.e., not only of DSBs themselves but also of the whole damage-surrounding chromatin domains) form another layer of complex DSB regulation. In the present article, we summarize the application of super-resolution single molecule localization microscopy (SMLM) for investigations of these structural aspects with emphasis on the relationship between the nano-architecture of radiation-induced repair foci (IRIFs), represented here by γH2AX foci, and their chromatin environment. Using irradiated HeLa cell cultures as an example, we show repair-dependent rearrangements of damaged chromatin and analyze the architecture of γH2AX repair clusters according to topological similarities. Although HeLa cells are known to have highly aberrant genomes, the topological similarity of γH2AX was high, indicating a functional, presumptively genome type-independent relevance of structural aspects in DSB repair. Remarkably, nano-scaled chromatin rearrangements during repair depended both on the chromatin domain type and the treatment. Based on these results, we demonstrate how the nano-architecture and topology of IRIFs and chromatin can be determined, point to the methodological relevance of SMLM, and discuss the consequences of the observed phenomena for the DSB repair network regulation or, for instance, radiation treatment outcomes.
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Affiliation(s)
- Michael Hausmann
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany; (C.N.); (A.B.); (T.G.); (G.H.)
| | - Martin Falk
- Institute of Biophysics, Czech Academy of Sciences, 612 65 Brno, Czech Republic;
| | - Charlotte Neitzel
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany; (C.N.); (A.B.); (T.G.); (G.H.)
| | - Andreas Hofmann
- Institute for Theoretical Physics, Heidelberg University, 69120 Heidelberg, Germany; (A.H.); (D.W.H.)
| | - Abin Biswas
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany; (C.N.); (A.B.); (T.G.); (G.H.)
| | - Theresa Gier
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany; (C.N.); (A.B.); (T.G.); (G.H.)
| | - Iva Falkova
- Institute of Biophysics, Czech Academy of Sciences, 612 65 Brno, Czech Republic;
| | - Dieter W. Heermann
- Institute for Theoretical Physics, Heidelberg University, 69120 Heidelberg, Germany; (A.H.); (D.W.H.)
| | - Georg Hildenbrand
- Kirchhoff Institute for Physics, Heidelberg University, 69120 Heidelberg, Germany; (C.N.); (A.B.); (T.G.); (G.H.)
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14
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Gupta P, Saha B, Chattopadhyay S, Patro BS. Pharmacological targeting of differential DNA repair, radio-sensitizes WRN-deficient cancer cells in vitro and in vivo. Biochem Pharmacol 2021; 186:114450. [PMID: 33571504 DOI: 10.1016/j.bcp.2021.114450] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/25/2021] [Accepted: 01/25/2021] [Indexed: 11/30/2022]
Abstract
Werner (WRN) expression is epigenetically downregulated in various tumors. It is imperative to understand differential repair process in WRN-proficient and WRN-deficient cancers to find pharmacological targets for radio-sensitization of WRN-deficient cancer. In the current investigation, we showed that pharmacological inhibition of CHK1 mediated homologous recombination repair (HRR), but not non-homologous end joining (NHEJ) repair, can causes hyper-radiosensitization of WRN-deficient cancers. This was confirmed in cancer cell lines of different tissue origin (osteosarcoma, colon adenocarcinoma and melanoma) with WRN silencing and overexpression. We established that WRN-depleted cells are dependent on a critical but compromised CHK1-mediated HRR-pathway for repairing ionizing radiation (IR) induced DSBs for their survival. Mechanistically, we unraveled a new finding that the MRE11, CTIP and WRN proteins are largely responsible for resections of late and persistent DSBs. In response to IR-treatment, MRE11 and CTIP-positively and WRN-negatively regulate p38-MAPK reactivation in a CHK1-dependent manner. A degradation resistant WRN protein, mutated at serine 1141, abrogates p38-MAPK activation. We also showed that CHK1-p38-MAPK axis plays important role in RAD51 mediated HRR in WRN-silenced cells. Like CHK1 inhibition, pharmacological-inhibition of p38-MAPK also hyper-radiosensitizes WRN-depleted cells by targeting HR-pathway. Combination treatment of CHK1-inhibitor (currently under various clinical trials) and IR exhibited a strong synergy against WRN-deficient melanoma tumor in vivo. Taken together, our findings suggest that pharmacological targeting of CHK1-p38-MAPK mediated HRR is an attractive strategy for enhancing therapeutic response of radiation treatment of cancer.
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Affiliation(s)
- Pooja Gupta
- Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - Bhaskar Saha
- Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Subrata Chattopadhyay
- Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - Birija Sankar Patro
- Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India.
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15
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Parsels LA, Engelke CG, Parsels J, Flanagan SA, Zhang Q, Tanska D, Wahl DR, Canman CE, Lawrence TS, Morgan MA. Combinatorial Efficacy of Olaparib with Radiation and ATR Inhibitor Requires PARP1 Protein in Homologous Recombination-Proficient Pancreatic Cancer. Mol Cancer Ther 2021; 20:263-273. [PMID: 33268569 PMCID: PMC7867626 DOI: 10.1158/1535-7163.mct-20-0365] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/06/2020] [Accepted: 11/09/2020] [Indexed: 11/16/2022]
Abstract
PARP inhibitor monotherapy (olaparib) was recently FDA approved for the treatment of BRCA1/2-mutant, homologous recombination (HR) repair-deficient pancreatic cancer. Most pancreatic cancers, however, are HR proficient and thus resistant to PARP inhibitor monotherapy. We tested the hypothesis that combined therapy with radiation and ataxia telangiectasia and Rad3-related (ATR) inhibitor (AZD6738) would extend the therapeutic indication of olaparib to HR-proficient pancreatic cancers. We show that olaparib combined with AZD6738 significantly reduced radiation survival relative to either agent alone, regardless of HR status. Whereas catalytic inhibition of PARP with low concentrations of olaparib radiosensitized HR-deficient models, maximal sensitization in HR-proficient models required concentrations of olaparib that induce formation of PARP1-DNA complexes. Furthermore, CRISPR-Cas9-mediated PARP1 deletion failed to recapitulate the effects of olaparib on radiosensitivity and negated the combinatorial efficacy of olaparib and AZD6738 on radiosensitization, suggesting that PARP1-DNA complexes, rather than PARP catalytic inhibition, were responsible for radiosensitization. Mechanistically, therapeutic concentrations of olaparib in combination with radiation and AZD6738 increased DNA double-strand breaks. DNA fiber combing revealed that high concentrations of olaparib did not stall replication forks but instead accelerated replication fork progression in association with an ATR-mediated replication stress response that was antagonized by AZD6738. Finally, in HR-proficient tumor xenografts, the combination of olaparib, radiation, and AZD6738 significantly delayed tumor growth compared with all other treatments. These findings suggest that PARP1-DNA complexes are required for the therapeutic activity of olaparib combined with radiation and ATR inhibitor in HR-proficient pancreatic cancer and support the clinical development of this combination for tumors intrinsically resistant to PARP inhibitors.
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Affiliation(s)
- Leslie A Parsels
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Carl G Engelke
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Joshua Parsels
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Sheryl A Flanagan
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Qiang Zhang
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Daria Tanska
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Daniel R Wahl
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Christine E Canman
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Theodore S Lawrence
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Meredith A Morgan
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan.
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16
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Nickoloff JA, Taylor L, Sharma N, Kato TA. Exploiting DNA repair pathways for tumor sensitization, mitigation of resistance, and normal tissue protection in radiotherapy. CANCER DRUG RESISTANCE (ALHAMBRA, CALIF.) 2021; 4:244-263. [PMID: 34337349 PMCID: PMC8323830 DOI: 10.20517/cdr.2020.89] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
More than half of cancer patients are treated with radiotherapy, which kills tumor cells by directly and indirectly inducing DNA damage, including cytotoxic DNA double-strand breaks (DSBs). Tumor cells respond to these threats by activating a complex signaling network termed the DNA damage response (DDR). The DDR arrests the cell cycle, upregulates DNA repair, and triggers apoptosis when damage is excessive. The DDR signaling and DNA repair pathways are fertile terrain for therapeutic intervention. This review highlights strategies to improve therapeutic gain by targeting DDR and DNA repair pathways to radiosensitize tumor cells, overcome intrinsic and acquired tumor radioresistance, and protect normal tissue. Many biological and environmental factors determine tumor and normal cell responses to ionizing radiation and genotoxic chemotherapeutics. These include cell type and cell cycle phase distribution; tissue/tumor microenvironment and oxygen levels; DNA damage load and quality; DNA repair capacity; and susceptibility to apoptosis or other active or passive cell death pathways. We provide an overview of radiobiological parameters associated with X-ray, proton, and carbon ion radiotherapy; DNA repair and DNA damage signaling pathways; and other factors that regulate tumor and normal cell responses to radiation. We then focus on recent studies exploiting DSB repair pathways to enhance radiotherapy therapeutic gain.
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Affiliation(s)
- Jac A. Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
- Correspondence Address: Dr. Jac A. Nickoloff, Department of Environmental and Radiological Health Sciences, Colorado State University, 1681 Campus Delivery, Ft. Collins, CO 80523-1681, USA. E-mail:
| | - Lynn Taylor
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Neelam Sharma
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
| | - Takamitsu A. Kato
- Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, CO 80523, USA
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17
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Wassing IE, Esashi F. RAD51: Beyond the break. Semin Cell Dev Biol 2020; 113:38-46. [PMID: 32938550 PMCID: PMC8082279 DOI: 10.1016/j.semcdb.2020.08.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/14/2020] [Accepted: 08/28/2020] [Indexed: 01/30/2023]
Abstract
As the primary catalyst of homologous recombination (HR) in vertebrates, RAD51 has been extensively studied in the context of repair of double-stranded DNA breaks (DSBs). With recent advances in the understanding of RAD51 function extending beyond DSBs, the importance of RAD51 throughout DNA metabolism has become increasingly clear. Here we review the suggested roles of RAD51 beyond HR, specifically focusing on their interplay with DNA replication and the maintenance of genomic stability, in which RAD51 function emerges as a double-edged sword.
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Affiliation(s)
- Isabel E Wassing
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Fumiko Esashi
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
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18
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Xu L, Wu T, Lu S, Hao X, Qin J, Wang J, Zhang X, Liu Q, Kong B, Gong Y, Liu Z, Shao C. Mitochondrial superoxide contributes to oxidative stress exacerbated by DNA damage response in RAD51-depleted ovarian cancer cells. Redox Biol 2020; 36:101604. [PMID: 32554304 PMCID: PMC7303666 DOI: 10.1016/j.redox.2020.101604] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 05/18/2020] [Accepted: 06/05/2020] [Indexed: 12/16/2022] Open
Abstract
Ovarian cancer is the most lethal gynecological malignancy. Abnormal homologous recombination repair, high level of reactive oxygen species (ROS) and upregulation of antioxidant genes are characteristic features of ovarian cancer. However, the molecular mechanisms governing the redox homeostasis in ovarian cancer cells remain to be fully elucidated. We here demonstrated a critical role of RAD51, a protein essential for homologous recombination, in the maintenance of redox homeostasis. We found that RAD51 is overexpressed in high grade serous ovarian cancer and is associated with poor prognosis. Depletion or inhibition of RAD51 results in G2/M arrest, increased production of reactive oxygen species and accumulation of oxidative DNA damage. Importantly, antioxidant N-acetylcysteine (NAC) significantly attenuated the induction of DNA damage and the perturbation of proliferation caused by RAD51 depletion. We further demonstrated that RAD51 inhibition or depletion led to elevated production of mitochondrial superoxide and increased accumulation of mitochondria. Moreover, CHK1 activation is required for the G2/M arrest and the generation of mitochondrial stress in response to RAD51 depletion. Together, our results indicate that nuclear DNA damage caused by RAD51 depletion may trigger mitochondria-originated redox dysregulation. Our findings suggest that a vicious cycle of nuclear DNA damage, mitochondrial accumulation and oxidative stress may contribute to the tumor-suppressive effects of RAD51 depletion or inhibition. RAD51 is overexpressed in ovarian cancer and is associated with poor prognosis. Depletion of RAD51 leads to increased mitochondrial superoxide production and oxidative DNA damage. Increased production of mitochondrial ROS requires CHK1-mediated G2/M arrest. mROS increase is independent of mtDNA.
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Affiliation(s)
- Limei Xu
- Key Laboratory of Experimental Teratology, Ministry of Education/Department of Molecular Medicine and Genetics, Shandong University School of Basic Medical Science, Jinan, Shandong, 250012, China
| | - Tingting Wu
- Key Laboratory of Experimental Teratology, Ministry of Education/Department of Molecular Medicine and Genetics, Shandong University School of Basic Medical Science, Jinan, Shandong, 250012, China
| | - Shihua Lu
- Key Laboratory of Experimental Teratology, Ministry of Education/Department of Molecular Medicine and Genetics, Shandong University School of Basic Medical Science, Jinan, Shandong, 250012, China
| | - Xiaohe Hao
- Key Laboratory of Experimental Teratology, Ministry of Education/Department of Molecular Medicine and Genetics, Shandong University School of Basic Medical Science, Jinan, Shandong, 250012, China
| | - Junchao Qin
- Department of Cell Biology, Shandong University School of Basic Medical Science, Jinan, Shandong, 250012, China
| | - Jing Wang
- Key Laboratory of Experimental Teratology, Ministry of Education/Department of Molecular Medicine and Genetics, Shandong University School of Basic Medical Science, Jinan, Shandong, 250012, China
| | - Xiyu Zhang
- Key Laboratory of Experimental Teratology, Ministry of Education/Department of Molecular Medicine and Genetics, Shandong University School of Basic Medical Science, Jinan, Shandong, 250012, China
| | - Qiao Liu
- Key Laboratory of Experimental Teratology, Ministry of Education/Department of Molecular Medicine and Genetics, Shandong University School of Basic Medical Science, Jinan, Shandong, 250012, China
| | - Beihua Kong
- Department of Obstetrics and Gynecology, Qilu Hospital of Shandong University, Jinan, Shandong, 250012, China
| | - Yaoqin Gong
- Key Laboratory of Experimental Teratology, Ministry of Education/Department of Molecular Medicine and Genetics, Shandong University School of Basic Medical Science, Jinan, Shandong, 250012, China
| | - Zhaojian Liu
- Department of Cell Biology, Shandong University School of Basic Medical Science, Jinan, Shandong, 250012, China
| | - Changshun Shao
- State Key Laboratory of Radiation Medicine and Protection, Institutes for Translational Medicine, Soochow University, Suzhou, Jiangsu, 215123, China.
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19
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Huang RX, Zhou PK. DNA damage response signaling pathways and targets for radiotherapy sensitization in cancer. Signal Transduct Target Ther 2020; 5:60. [PMID: 32355263 PMCID: PMC7192953 DOI: 10.1038/s41392-020-0150-x] [Citation(s) in RCA: 475] [Impact Index Per Article: 118.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/20/2020] [Accepted: 03/16/2020] [Indexed: 12/19/2022] Open
Abstract
Radiotherapy is one of the most common countermeasures for treating a wide range of tumors. However, the radioresistance of cancer cells is still a major limitation for radiotherapy applications. Efforts are continuously ongoing to explore sensitizing targets and develop radiosensitizers for improving the outcomes of radiotherapy. DNA double-strand breaks are the most lethal lesions induced by ionizing radiation and can trigger a series of cellular DNA damage responses (DDRs), including those helping cells recover from radiation injuries, such as the activation of DNA damage sensing and early transduction pathways, cell cycle arrest, and DNA repair. Obviously, these protective DDRs confer tumor radioresistance. Targeting DDR signaling pathways has become an attractive strategy for overcoming tumor radioresistance, and some important advances and breakthroughs have already been achieved in recent years. On the basis of comprehensively reviewing the DDR signal pathways, we provide an update on the novel and promising druggable targets emerging from DDR pathways that can be exploited for radiosensitization. We further discuss recent advances identified from preclinical studies, current clinical trials, and clinical application of chemical inhibitors targeting key DDR proteins, including DNA-PKcs (DNA-dependent protein kinase, catalytic subunit), ATM/ATR (ataxia-telangiectasia mutated and Rad3-related), the MRN (MRE11-RAD50-NBS1) complex, the PARP (poly[ADP-ribose] polymerase) family, MDC1, Wee1, LIG4 (ligase IV), CDK1, BRCA1 (BRCA1 C terminal), CHK1, and HIF-1 (hypoxia-inducible factor-1). Challenges for ionizing radiation-induced signal transduction and targeted therapy are also discussed based on recent achievements in the biological field of radiotherapy.
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Affiliation(s)
- Rui-Xue Huang
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, 410078, Changsha, People's Republic of China
| | - Ping-Kun Zhou
- Department of Radiation Biology, Beijing Key Laboratory for Radiobiology, Beijing Institute of Radiation Medicine, AMMS, 100850, Beijing, People's Republic of China.
- Institute for Chemical Carcinogenesis, State Key Laboratory of Respiratory, Guangzhou Medical University, 511436, Guangzhou, People's Republic of China.
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20
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Tatebe K, Chmura SJ, Connell PP. Elevated Radiation Therapy Toxicity in the Setting of Germline PTEN Mutation. Pract Radiat Oncol 2019; 9:492-495. [PMID: 31185301 DOI: 10.1016/j.prro.2019.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 05/30/2019] [Accepted: 06/02/2019] [Indexed: 10/26/2022]
Affiliation(s)
- Ken Tatebe
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois
| | - Steven J Chmura
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois
| | - Philip P Connell
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois.
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21
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Yang X, Lu Y, He F, Hou F, Xing C, Xu P, Wang QF. Benzene metabolite hydroquinone promotes DNA homologous recombination repair via the NF-κB pathway. Carcinogenesis 2019; 40:1021-1030. [PMID: 30770924 DOI: 10.1093/carcin/bgy157] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 10/11/2018] [Indexed: 12/29/2022] Open
Abstract
Abstract
Benzene, a widespread environmental pollutant, induces DNA double-strand breaks (DSBs) and DNA repair, which may further lead to oncogenic mutations, chromosomal rearrangements and leukemogenesis. However, the molecular mechanisms underlying benzene-induced DNA repair and carcinogenesis remain unclear. The human osteosarcoma cell line (U2OS/DR-GFP), which carries a GFP-based homologous recombination (HR) repair reporter, was treated with hydroquinone, one of the major benzene metabolites, to identify the potential effects of benzene on DSB HR repair. RNA-sequencing was further employed to identify the potential key pathway that contributed to benzene-initiated HR repair. We found that treatment with hydroquinone induced a significant increase in HR. NF-κB pathway, which plays a critical role in carcinogenesis in multiple tumors, was significantly activated in cells recovered from hydroquinone treatment. Furthermore, the upregulation of NF-κB by hydroquinone was also found in human hematopoietic stem and progenitor cells. Notably, the inhibition of NF-κB activity by small molecule inhibitors (QNZ and JSH-23) significantly reduced the frequency of hydroquinone-initiated HR (−1.36- and −1.77-fold, respectively, P < 0.01). Our results demonstrate an important role of NF-κB activity in promoting HR repair induced by hydroquinone. This finding sheds light on the underlying mechanisms involved in benzene-induced genomic instability and leukemogenesis and may contribute to the larger exploration of the influence of other environmental pollutants on carcinogenesis.
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Affiliation(s)
- Xuejing Yang
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Chemical Safety and Health, National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yedan Lu
- Key Laboratory of Chemical Safety and Health, National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China
| | - Fuhong He
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Fenxia Hou
- Key Laboratory of Chemical Safety and Health, National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Caihong Xing
- Key Laboratory of Chemical Safety and Health, National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Peiyu Xu
- Department of Nutrition, Food Safety and Toxicology, West China School of Public Health, Sichuan University, Chengdu, Sichuan, China
| | - Qian-Fei Wang
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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22
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Chlenski A, Park C, Dobratic M, Salwen HR, Budke B, Park JH, Miller R, Applebaum MA, Wilkinson E, Nakamura Y, Connell PP, Cohn SL. Maternal Embryonic Leucine Zipper Kinase (MELK), a Potential Therapeutic Target for Neuroblastoma. Mol Cancer Ther 2019; 18:507-516. [PMID: 30674566 DOI: 10.1158/1535-7163.mct-18-0819] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 12/07/2018] [Accepted: 01/15/2019] [Indexed: 01/10/2023]
Abstract
Maternal embryonic leucine zipper kinase (MELK) activates pathways that mediate aggressive tumor growth and therapy resistance in many types of adult cancers. Pharmacologic and genomic inhibition of MELK impairs tumor growth and increases sensitivity to radiation and chemotherapy. On the basis of these promising preclinical studies, early-phase adult clinical trials testing the MELK inhibitor OTS167 are ongoing. To investigate whether MELK is also a therapeutic target in neuroblastoma, we analyzed MELK expression in primary tumors and cell lines, and examined the effects of OTS167 on neuroblastoma growth. In primary tumors, high levels of MELK were associated with advanced stage disease and inferior survival. Higher levels of MELK were also detected in tumorigenic versus nontumorigenic neuroblastoma cell lines, and cells with higher levels of MELK expression were more sensitive to OTS167 than low-MELK expressing cells. OTS167 suppressed the growth of neuroblastoma xenografts, and in a preclinical model of minimal residual disease, survival was prolonged with MELK inhibition. OTS167 treatment downregulated MELK and its target enhancer of zeste homolog 2 (EZH2), a component of the polycomb repressive complex 2 (PRC2) that is known to modulate the DNA damage response. We also show that OTS167 reduced the formation of collapsed replication forks induced by camptothecin or radiation. Taken together, our results indicate that MELK indirectly mediates efficient processing of replication-associated DNA lesions in neuroblastoma, and that OTS167 sensitizes cells to DNA-damaging agents by abrogating this process. Further studies evaluating the activity of combination treatment regimens with OTS167 in neuroblastoma are warranted.
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Affiliation(s)
| | - Chanyoung Park
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois
| | - Marija Dobratic
- Department of Pediatrics, University of Chicago, Chicago, Illinois
| | - Helen R Salwen
- Department of Pediatrics, University of Chicago, Chicago, Illinois
| | - Brian Budke
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois
| | - Jae-Hyun Park
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Ryan Miller
- Department of Pediatrics, University of Chicago, Chicago, Illinois
| | - Mark A Applebaum
- Department of Pediatrics, University of Chicago, Chicago, Illinois
| | - Emma Wilkinson
- Department of Pediatrics, University of Chicago, Chicago, Illinois
| | - Yusuke Nakamura
- Department of Medicine, University of Chicago, Chicago, Illinois
- Department of Surgery, University of Chicago, Chicago, Illinois
| | - Philip P Connell
- Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois
| | - Susan L Cohn
- Department of Pediatrics, University of Chicago, Chicago, Illinois.
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23
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Abdelfattah N, Rajamanickam S, Panneerdoss S, Timilsina S, Yadav P, Onyeagucha BC, Garcia M, Vadlamudi R, Chen Y, Brenner A, Houghton P, Rao MK. MiR-584-5p potentiates vincristine and radiation response by inducing spindle defects and DNA damage in medulloblastoma. Nat Commun 2018; 9:4541. [PMID: 30382096 PMCID: PMC6208371 DOI: 10.1038/s41467-018-06808-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 09/18/2018] [Indexed: 12/24/2022] Open
Abstract
Despite improvements in overall survival, only a modest percentage of patients survives high-risk medulloblastoma. The devastating side effects of radiation and chemotherapy substantially reduce quality of life for surviving patients. Here, using genomic screens, we identified miR-584-5p as a potent therapeutic adjuvant that potentiates medulloblastoma to radiation and vincristine. MiR-584-5p inhibited medulloblastoma growth and prolonged survival of mice in pre-clinical tumor models. MiR-584-5p overexpression caused cell cycle arrest, DNA damage, and spindle defects in medulloblastoma cells. MiR-584-5p mediated its tumor suppressor and therapy-sensitizing effects by targeting HDAC1 and eIF4E3. MiR-584-5p overexpression or HDAC1/eIF4E3 silencing inhibited medulloblastoma stem cell self-renewal without affecting neural stem cell growth. In medulloblastoma patients, reduced expression of miR-584-5p correlated with increased levels of HDAC1/eIF4E3. These findings identify a previously undefined role for miR-584-5p/HDAC1/eIF4E3 in regulating DNA repair, microtubule dynamics, and stemness in medulloblastoma and set the stage for a new way to treat medulloblastoma using miR-584-5p.
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Affiliation(s)
- Nourhan Abdelfattah
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Department of Chemistry, Faculty of Science, Cairo University, Cairo, 12613, Egypt
| | - Subapriya Rajamanickam
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Subbarayalu Panneerdoss
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Santosh Timilsina
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Pooja Yadav
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Benjamin C Onyeagucha
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Michael Garcia
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Ratna Vadlamudi
- Department of Obstetrics and Gynecology, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Yidong Chen
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Department of Epidemiology and Statistics, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Andrew Brenner
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Peter Houghton
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
| | - Manjeet K Rao
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA.
- Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA.
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24
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Burdak-Rothkamm S, Rothkamm K. Radiation-induced bystander and systemic effects serve as a unifying model system for genotoxic stress responses. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2018; 778:13-22. [DOI: 10.1016/j.mrrev.2018.08.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/13/2018] [Accepted: 08/15/2018] [Indexed: 12/19/2022]
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25
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Sunavala-Dossabhoy G. Preserving salivary gland physiology against genotoxic damage - the Tousled way. Oral Dis 2018; 24:1390-1398. [PMID: 29383801 DOI: 10.1111/odi.12836] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 01/23/2018] [Accepted: 01/23/2018] [Indexed: 12/23/2022]
Abstract
Tousled and its homologs are evolutionarily conserved serine/threonine kinases present in plants and animals. Human Tousled-like kinases, TLK1 and TLK2, are implicated in chromatin assembly during DNA replication, chromosome segregation during mitosis, as well as in DNA damage response and repair. They share a high degree of sequence similarity, but have few non-redundant functions. Our laboratory has studied TLK1 and found that it increases the resistance of cells to ionizing radiation (IR) damage through expedited double-strand break (DSB) repair. DSBs are life-threatening lesions which when repaired restore DNA integrity and promote cell survival. A major focus in our laboratory is to dissect TLK1's role in DSB response and repair and study its usefulness in averting salivary gland hypofunction, a condition that invariably afflicts patients undergoing regional radiotherapy. The identification of anti-silencing factor 1 (ASF1), histone H3, and Rad9 as substrates of TLK1 links the protein to chromatin organization and DNA damage response and repair. However, recent findings of new interacting partners that include NEK1 suggest that TLK1 may play a broader role in DSB repair. This review provides a brief overview of the DNA damage response and DSB repair, and it highlights our current understanding of TLK1 in the process.
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Affiliation(s)
- G Sunavala-Dossabhoy
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
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26
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Hromas R, Kim HS, Sidhu G, Williamson E, Jaiswal A, Totterdale TA, Nole J, Lee SH, Nickoloff JA, Kong KY. The endonuclease EEPD1 mediates synthetic lethality in RAD52-depleted BRCA1 mutant breast cancer cells. Breast Cancer Res 2017; 19:122. [PMID: 29145865 PMCID: PMC5693420 DOI: 10.1186/s13058-017-0912-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Accepted: 10/30/2017] [Indexed: 02/06/2023] Open
Abstract
Background Proper repair and restart of stressed replication forks requires intact homologous recombination (HR). HR at stressed replication forks can be initiated by the 5′ endonuclease EEPD1, which cleaves the stalled replication fork. Inherited or acquired defects in HR, such as mutations in breast cancer susceptibility protein-1 (BRCA1) or BRCA2, predispose to cancer, including breast and ovarian cancers. In order for these HR-deficient tumor cells to proliferate, they become addicted to a bypass replication fork repair pathway mediated by radiation repair protein 52 (RAD52). Depleting RAD52 can cause synthetic lethality in BRCA1/2 mutant cancers by an unknown molecular mechanism. Methods We hypothesized that cleavage of stressed replication forks by EEPD1 generates a fork repair intermediate that is toxic when HR-deficient cells cannot complete repair with the RAD52 bypass pathway. To test this hypothesis, we applied cell survival assays, immunofluorescence staining, DNA fiber and western blot analyses to look at the correlation between cell survival and genome integrity in control, EEPD1, RAD52 and EEPD1/RAD52 co-depletion BRCA1-deficient breast cancer cells. Results Our data show that depletion of EEPD1 suppresses synthetic lethality, genome instability, mitotic catastrophe, and hypersensitivity to stress of replication of RAD52-depleted, BRCA1 mutant breast cancer cells. Without HR and the RAD52-dependent backup pathway, the BRCA1 mutant cancer cells depleted of EEPD1 skew to the alternative non-homologous end-joining DNA repair pathway for survival. Conclusion This study indicates that the mechanism of synthetic lethality in RAD52-depleted BRCA1 mutant cancer cells depends on the endonuclease EEPD1. The data imply that EEPD1 cleavage of stressed replication forks may result in a toxic intermediate when replication fork repair cannot be completed. Electronic supplementary material The online version of this article (doi:10.1186/s13058-017-0912-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Robert Hromas
- Department of Medicine and the Cancer Center, University of Florida Health, 1600 SW Archer Rd, Gainesville, FL, 32610, USA.
| | - Hyun-Suk Kim
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Gurjit Sidhu
- Department of Medicine and the Cancer Center, University of Florida Health, 1600 SW Archer Rd, Gainesville, FL, 32610, USA
| | - Elizabeth Williamson
- Department of Medicine and the Cancer Center, University of Florida Health, 1600 SW Archer Rd, Gainesville, FL, 32610, USA
| | - Aruna Jaiswal
- Department of Medicine and the Cancer Center, University of Florida Health, 1600 SW Archer Rd, Gainesville, FL, 32610, USA
| | - Taylor A Totterdale
- Department of Medicine and the Cancer Center, University of Florida Health, 1600 SW Archer Rd, Gainesville, FL, 32610, USA
| | - Jocelyn Nole
- Department of Medicine and the Cancer Center, University of Florida Health, 1600 SW Archer Rd, Gainesville, FL, 32610, USA
| | - Suk-Hee Lee
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Jac A Nickoloff
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, 80523, USA
| | - Kimi Y Kong
- Department of Medicine and the Cancer Center, University of Florida Health, 1600 SW Archer Rd, Gainesville, FL, 32610, USA.
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27
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Pires E, Sung P, Wiese C. Role of RAD51AP1 in homologous recombination DNA repair and carcinogenesis. DNA Repair (Amst) 2017; 59:76-81. [PMID: 28963981 PMCID: PMC5643253 DOI: 10.1016/j.dnarep.2017.09.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/01/2017] [Accepted: 09/21/2017] [Indexed: 12/11/2022]
Abstract
Homologous recombination (HR) serves to repair DNA double-strand breaks and damaged replication forks and is essential for maintaining genome stability and tumor suppression. HR capacity also determines the efficacy of anticancer therapy. Hence, there is an urgent need to better understand all HR proteins and sub-pathways. An emerging protein that is critical for RAD51-mediated HR is RAD51-associated protein 1 (RAD51AP1). Although much has been learned about its biochemical attributes, the precise molecular role of RAD51AP1 in the HR reaction is not yet fully understood. The available literature also suggests that RAD51AP1 expression may be relevant for cancer development and progression. Here, we review the efforts that led to the discovery of RAD51AP1 and elaborate on our current understanding of its biochemical profile and biological function. We also discuss how RAD51AP1 may help to promote cancer development and why it could potentially represent a promising new target for therapeutic intervention.
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Affiliation(s)
- Elena Pires
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA; Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
| | - Patrick Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Claudia Wiese
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA.
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28
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Abstract
Cellular chromosomal DNA is the principal target through which ionising radiation exerts it diverse biological effects. This chapter summarises the relevant DNA damage signalling and repair pathways used by normal and tumour cells in response to irradiation. Strategies for tumour radiosensitisation are reviewed which exploit tumour-specific DNA repair deficiencies or signalling pathway addictions, with a special focus on growth factor signalling, PARP, cancer stem cells, cell cycle checkpoints and DNA replication. This chapter concludes with a discussion of DNA repair-related candidate biomarkers of tumour response which are of crucial importance for implementing precision medicine in radiation oncology.
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29
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Nickoloff JA, Boss MK, Allen CP, LaRue SM. Translational research in radiation-induced DNA damage signaling and repair. Transl Cancer Res 2017; 6:S875-S891. [PMID: 30574452 PMCID: PMC6298755 DOI: 10.21037/tcr.2017.06.02] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Radiotherapy is an effective tool in the fight against cancer. It is non-invasive and painless, and with advanced tumor imaging and beam control systems, radiation can be delivered to patients safely, generally with minor or no adverse side effects, accounting for its increasing use against a broad range of tumors. Tumors and normal cells respond to radiation-induced DNA damage by activating a complex network of DNA damage signaling and repair pathways that determine cell fate including survival, death, and genome stability. DNA damage response (DDR) proteins represent excellent targets to augment radiotherapy, and many agents that inhibit key response proteins are being combined with radiation and genotoxic chemotherapy in clinical trials. This review focuses on how insights into molecular mechanisms of DDR pathways are translated to small animal preclinical studies, to clinical studies of naturally occurring tumors in companion animals, and finally to human clinical trials. Companion animal studies, under the umbrella of comparative oncology, have played key roles in the development of clinical radiotherapy throughout its >100-year history. There is growing appreciation that rapid translation of basic knowledge of DNA damage and repair systems to improved radiotherapy practice requires a comprehensive approach that embraces the full spectrum of cancer research, with companion animal clinical trials representing a critical bridge between small animal preclinical studies, and human clinical trials.
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Affiliation(s)
- Jac A Nickoloff
- Department of Environmental and Radiological Health Sciences, Flint Animal Cancer Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Mary-Keara Boss
- Department of Environmental and Radiological Health Sciences, Flint Animal Cancer Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Christopher P Allen
- Department of Environmental and Radiological Health Sciences, Flint Animal Cancer Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Susan M LaRue
- Department of Environmental and Radiological Health Sciences, Flint Animal Cancer Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
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30
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Bhattacharya S, Asaithamby A. Repurposing DNA repair factors to eradicate tumor cells upon radiotherapy. Transl Cancer Res 2017; 6:S822-S839. [PMID: 30613483 DOI: 10.21037/tcr.2017.05.22] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cancer is the leading cause of death worldwide. Almost 50% of all cancer patients undergo radiation therapy (RT) during treatment, with varying success. The main goal of RT is to kill tumor cells by damaging their DNA irreversibly while sparing the surrounding normal tissue. The outcome of RT is often determined by how tumors recognize and repair their damaged DNA. A growing body of evidence suggests that tumors often show abnormal expression of DNA double-strand break (DSB) repair genes that are absent from normal cells. Defects in a specific DNA repair pathway make tumor cells overly dependent on alternative or backup pathways to repair their damaged DNA. These tumor cell-specific abnormalities in the DNA damage response (DDR) machinery can potentially be used as biomarkers for treatment outcomes or as targets for sensitization to ionizing radiation (IR). An improved understanding of genetic or epigenetic alterations in the DNA repair pathways specific to cancer cells has paved the way for new treatments that combine pharmacological exploitation of tumor-specific molecular vulnerabilities with IR. Inhibiting DNA repair pathways has the potential to greatly enhance the therapeutic ratio of RT. In this review, we will discuss DNA repair pathways in active cells and how these pathways are deregulated in tumors. We will also describe the impact of targeting cancer-specific aberrations in the DDR as a treatment strategy to improve the efficacy of RT. Finally, we will address the current roadblocks and future prospects of these approaches.
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Affiliation(s)
- Souparno Bhattacharya
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Aroumougame Asaithamby
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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31
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Allen CP, Hirakawa H, Nakajima NI, Moore S, Nie J, Sharma N, Sugiura M, Hoki Y, Araki R, Abe M, Okayasu R, Fujimori A, Nickoloff JA. Low- and High-LET Ionizing Radiation Induces Delayed Homologous Recombination that Persists for Two Weeks before Resolving. Radiat Res 2017; 188:82-93. [PMID: 28535128 DOI: 10.1667/rr14748.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Genome instability is a hallmark of cancer cells and dysregulation or defects in DNA repair pathways cause genome instability and are linked to inherited cancer predisposition syndromes. Ionizing radiation can cause immediate effects such as mutation or cell death, observed within hours or a few days after irradiation. Ionizing radiation also induces delayed effects many cell generations after irradiation. Delayed effects include hypermutation, hyper-homologous recombination, chromosome instability and reduced clonogenic survival (delayed death). Delayed hyperrecombination (DHR) is mechanistically distinct from delayed chromosomal instability and delayed death. Using a green fluorescent protein (GFP) direct repeat homologous recombination system, time-lapse microscopy and colony-based assays, we demonstrate that DHR increases several-fold in response to low-LET X rays and high-LET carbon-ion radiation. Time-lapse analyses of DHR revealed two classes of recombinants not detected in colony-based assays, including cells that recombined and then senesced or died. With both low- and high-LET radiation, DHR was evident during the first two weeks postirradiation, but resolved to background levels during the third week. The results indicate that the risk of radiation-induced genome destabilization via DHR is time limited, and suggest that there is little or no additional risk of radiation-induced genome instability mediated by DHR with high-LET radiation compared to low-LET radiation.
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Affiliation(s)
- Christopher P Allen
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Hirokazu Hirakawa
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Nakako Izumi Nakajima
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Sophia Moore
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Jingyi Nie
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Neelam Sharma
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
| | - Mayumi Sugiura
- c Division of Natural Sciences, Research Group of Biological Sciences, Nara Women's University, Nara, Japan
| | - Yuko Hoki
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Ryoko Araki
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Masumi Abe
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Ryuichi Okayasu
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Akira Fujimori
- b Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba, Japan
| | - Jac A Nickoloff
- a Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado
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32
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Lysines 3241 and 3260 of DNA-PKcs are important for genomic stability and radioresistance. Biochem Biophys Res Commun 2016; 477:235-40. [PMID: 27297111 DOI: 10.1016/j.bbrc.2016.06.048] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 06/09/2016] [Indexed: 11/22/2022]
Abstract
DNA-dependent protein kinase (DNA-PK) is a serine/threonine kinase that plays an essential role in the repair of DNA double-strand breaks (DSBs) in the non-homologous end-joining (NHEJ) pathway. The DNA-PK holoenzyme consists of a catalytic subunit (DNA-PKcs) and DNA-binding subunit (Ku70/80, Ku). Ku is a molecular sensor for double-stranded DNA and once bound to DSB ends it recruits DNA-PKcs to the DSB site. Subsequently, DNA-PKcs is activated and heavily phosphorylated, with these phosphorylations modulating DNA-PKcs. Although phosphorylation of DNA-PKcs is well studied, other post-translational modifications of DNA-PKcs are not. In this study, we aimed to determine if acetylation of DNA-PKcs regulates DNA-PKcs-dependent DSB repair. We report that DNA-PKcs is acetylated in vivo and identified two putative acetylation sites, lysine residues 3241 and 3260. Mutating these sites to block potential acetylation results in increased radiosensitive, a slight decrease in DSB repair capacity as assessed by γH2AX resolution, and increased chromosomal aberrations, especially quadriradial chromosomes. Together, our results provide evidence that acetylation potentially regulates DNA-PKcs.
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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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Timiri Shanmugam PS, Nair RP, De Benedetti A, Caldito G, Abreo F, Sunavala-Dossabhoy G. Tousled kinase activator, gallic acid, promotes homologous recombinational repair and suppresses radiation cytotoxicity in salivary gland cells. Free Radic Biol Med 2016; 93:217-26. [PMID: 26855419 PMCID: PMC5257199 DOI: 10.1016/j.freeradbiomed.2015.12.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 12/18/2015] [Accepted: 12/24/2015] [Indexed: 01/19/2023]
Abstract
Accidental or medical radiation exposure of the salivary glands can gravely impact oral health. Previous studies have shown the importance of Tousled-like kinase 1 (TLK1) and its alternate start variant TLK1B in cell survival against genotoxic stresses. Through a high-throughput library screening of natural compounds, the phenolic phytochemical, gallic acid (GA), was identified as a modulator of TLK1/1B. This small molecule possesses anti-oxidant and free radical scavenging properties, but in this study, we report that in vitro it promotes survival of human salivary acinar cells, NS-SV-AC, through repair of ionizing radiation damage. Irradiated cells treated with GA show improved clonogenic survival compared to untreated controls. And, analyses of DNA repair kinetics by alkaline single-cell gel electrophoresis and γ-H2AX foci immunofluorescence indicate rapid resolution of DNA breaks in drug-treated cells. Study of DR-GFP transgene repair indicates GA facilitates homologous recombinational repair to establish a functional GFP gene. In contrast, inactivation of TLK1 or its shRNA knockdown suppressed resolution of radiation-induced DNA tails in NS-SV-AC, and homology directed repair in DR-GFP cells. Consistent with our results in culture, animals treated with GA after exposure to fractionated radiation showed better preservation of salivary function compared to saline-treated animals. Our results suggest that GA-mediated transient modulation of TLK1 activity promotes DNA repair and suppresses radiation cytoxicity in salivary gland cells.
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Affiliation(s)
- Prakash Srinivasan Timiri Shanmugam
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Renjith Parameshwaran Nair
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Arrigo De Benedetti
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Gloria Caldito
- Department of Computational Biology and Bioinformatics, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Fleurette Abreo
- Department of Pathology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA
| | - Gulshan Sunavala-Dossabhoy
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA.
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Lai TH, Ewald B, Zecevic A, Liu C, Sulda M, Papaioannou D, Garzon R, Blachly JS, Plunkett W, Sampath D. HDAC Inhibition Induces MicroRNA-182, which Targets RAD51 and Impairs HR Repair to Sensitize Cells to Sapacitabine in Acute Myelogenous Leukemia. Clin Cancer Res 2016; 22:3537-49. [PMID: 26858310 DOI: 10.1158/1078-0432.ccr-15-1063] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 01/27/2016] [Indexed: 12/31/2022]
Abstract
PURPOSE The double-strand breaks elicited by sapacitabine, a clinically active nucleoside analogue prodrug, are repaired by RAD51 and the homologous recombination repair (HR) pathway, which could potentially limit its toxicity. We investigated the mechanism by which histone deacetylase (HDAC) inhibitors targeted RAD51 and HR to sensitize acute myelogenous leukemia (AML) cells to sapacitabine. EXPERIMENTAL DESIGN Chromatin immunoprecipitation identified the role of HDACs in silencing miR-182 in AML. Immunoblotting, gene expression, overexpression, or inhibition of miR-182 and luciferase assays established that miR-182 directly targeted RAD51. HR reporter assays, apoptotic assays, and colony-forming assays established that the miR-182, as well as the HDAC inhibition-mediated decreases in RAD51 inhibited HR repair and sensitized cells to sapacitabine. RESULTS The gene repressors, HDAC1 and HDAC2, became recruited to the promoter of miR-182 to silence its expression in AML. HDAC inhibition induced miR-182 in AML cell lines and primary AML blasts. miR-182 targeted RAD51 protein both in luciferase assays and in AML cells. Overexpression of miR-182, as well as HDAC inhibition-mediated induction of miR-182 were linked to time- and dose-dependent decreases in the levels of RAD51, an inhibition of HR, increased levels of residual damage, and decreased survival after exposure to double-strand damage-inducing agents. CONCLUSIONS Our findings define the mechanism by which HDAC inhibition induces miR-182 to target RAD51 and highlights a novel pharmacologic strategy that compromises the ability of AML cells to conduct HR, thereby sensitizing AML cells to DNA-damaging agents that activate HR as a repair and potential resistance mechanism. Clin Cancer Res; 22(14); 3537-49. ©2016 AACR.
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Affiliation(s)
- Tsung-Huei Lai
- Division of Hematology, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Brett Ewald
- Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas
| | - Alma Zecevic
- Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas
| | - Chaomei Liu
- Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas
| | - Melanie Sulda
- Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas
| | - Dimitrios Papaioannou
- Division of Hematology, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Ramiro Garzon
- Division of Hematology, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - James S Blachly
- Division of Hematology, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - William Plunkett
- Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas.
| | - Deepa Sampath
- Division of Hematology, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio.
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Kan C, Zhang J. BRCA1 Mutation: A Predictive Marker for Radiation Therapy? Int J Radiat Oncol Biol Phys 2015; 93:281-93. [PMID: 26383678 DOI: 10.1016/j.ijrobp.2015.05.037] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/08/2015] [Accepted: 05/21/2015] [Indexed: 02/01/2023]
Abstract
DNA repair, in particular, DNA double-strand break (DSB) repair, is essential for the survival of both normal and cancer cells. An elaborate repair mechanism has been developed in cells to efficiently repair the damaged DNA. The pathways predominately involved in DSB repair are homologous recombination and classic nonhomologous end-joining, although the alternative NHEJ pathway, a third DSB repair pathway, could also be important in certain contexts. The protein of BRCA1 encoded by the tumor suppressor gene BRCA1 regulates all DSB repair pathways. Given that DSBs represent the most biologically significant lesions induced by ionizing radiation and that impaired DSB repair leads to radiation sensitivity, it has been expected that cancer patients with BRCA1 mutations should benefit from radiation therapy. However, the clinical data have been conflicting and inconclusive. We provide an overview about the current status of the data regarding BRCA1 deficiency and radiation therapy sensitivity in both experimental models and clinical investigations. In addition, we discuss a strategy to potentiate the effects of radiation therapy by poly(ADP-ribose) polymerase inhibitors, the pharmacologic drugs being investigated as monotherapy for the treatment of patients with BRCA1/2 mutations.
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Affiliation(s)
- Charlene Kan
- Department of Radiation Oncology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Junran Zhang
- Department of Radiation Oncology, Case Western Reserve University School of Medicine, Cleveland, Ohio.
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Herr P, Lundin C, Evers B, Ebner D, Bauerschmidt C, Kingham G, Palmai-Pallag T, Mortusewicz O, Frings O, Sonnhammer E, Helleday T. A genome-wide IR-induced RAD51 foci RNAi screen identifies CDC73 involved in chromatin remodeling for DNA repair. Cell Discov 2015; 1:15034. [PMID: 27462432 PMCID: PMC4860774 DOI: 10.1038/celldisc.2015.34] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 09/16/2015] [Indexed: 12/11/2022] Open
Abstract
To identify new regulators of homologous recombination repair, we carried out a genome-wide short-interfering RNA screen combined with ionizing irradiation using RAD51 foci formation as readout. All candidates were confirmed by independent short-interfering RNAs and validated in secondary assays like recombination repair activity and RPA foci formation. Network analysis of the top modifiers identified gene clusters involved in recombination repair as well as components of the ribosome, the proteasome and the spliceosome, which are known to be required for effective DNA repair. We identified and characterized the RNA polymerase II-associated protein CDC73/Parafibromin as a new player in recombination repair and show that it is critical for genomic stability. CDC73 interacts with components of the SCF/Cullin and INO80/NuA4 chromatin-remodeling complexes to promote Histone ubiquitination. Our findings indicate that CDC73 is involved in local chromatin decondensation at sites of DNA damage to promote DNA repair. This function of CDC73 is related to but independent of its role in transcriptional elongation.
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Affiliation(s)
- Patrick Herr
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet , Stockholm, Sweden
| | - Cecilia Lundin
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet , Stockholm, Sweden
| | - Bastiaan Evers
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet , Stockholm, Sweden
| | - Daniel Ebner
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford , Headington, UK
| | - Christina Bauerschmidt
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford , Headington, UK
| | - Guy Kingham
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford , Oxford, UK
| | | | - Oliver Mortusewicz
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet , Stockholm, Sweden
| | - Oliver Frings
- Science for Life Laboratory, Bioinformatics Centre Stockholm, Department of Biochemistry and Biophysics, Stockholm University , Stockholm, Sweden
| | - Erik Sonnhammer
- Science for Life Laboratory, Bioinformatics Centre Stockholm, Department of Biochemistry and Biophysics, Stockholm University , Stockholm, Sweden
| | - Thomas Helleday
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet , Stockholm, Sweden
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38
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Somaiah N, Rothkamm K, Yarnold J. Where Do We Look for Markers of Radiotherapy Fraction Size Sensitivity? Clin Oncol (R Coll Radiol) 2015; 27:570-8. [PMID: 26108884 DOI: 10.1016/j.clon.2015.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 03/31/2015] [Accepted: 06/06/2015] [Indexed: 02/06/2023]
Abstract
The response of human normal tissues to radiotherapy fraction size is often described in terms of cellular recovery, but the causal links between cellular and tissue responses to ionising radiation are not necessarily straightforward. This article reviews the evidence for a cellular basis to clinical fractionation sensitivity in normal tissues and discusses the significance of a long-established inverse association between fractionation sensitivity and proliferative indices. Molecular mechanisms of fractionation sensitivity involving DNA damage repair and cell cycle control are proposed that will probably require modification before being applicable to human cancer. The article concludes by discussing the kind of correlative research needed to test for and validate predictive biomarkers of tumour fractionation sensitivity.
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Affiliation(s)
- N Somaiah
- The Institute of Cancer Research & The Royal Marsden NHS Foundation Trust, London, UK.
| | - K Rothkamm
- University Medical Center, Hamburg-Eppendorf, Germany
| | - J Yarnold
- The Institute of Cancer Research & The Royal Marsden NHS Foundation Trust, London, UK
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39
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Tsai JY, Chen FH, Hsieh TY, Hsiao YY. Effects of indirect actions and oxygen on relative biological effectiveness: estimate of DSB induction and conversion induced by gamma rays and helium ions. JOURNAL OF RADIATION RESEARCH 2015; 56:691-699. [PMID: 25902742 PMCID: PMC4497398 DOI: 10.1093/jrr/rrv025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 03/17/2015] [Accepted: 03/21/2015] [Indexed: 06/04/2023]
Abstract
Clustered DNA damage other than double-strand breaks (DSBs) can be detrimental to cells and can lead to mutagenesis or cell death. In addition to DSBs induced by ionizing radiation, misrepair of non-DSB clustered damage contributes extra DSBs converted from DNA misrepair via pathways for base excision repair and nucleotide excision repair. This study aimed to quantify the relative biological effectiveness (RBE) when DSB induction and conversion from non-DSB clustered damage misrepair were used as biological endpoints. The results showed that both linear energy transfer (LET) and indirect action had a strong impact on the yields for DSB induction and conversion. RBE values for DSB induction and maximum DSB conversion of helium ions (LET = 120 keV/μm) to (60)Co gamma rays were 3.0 and 3.2, respectively. These RBE values increased to 5.8 and 5.6 in the absence of interference of indirect action initiated by addition of 2-M dimethylsulfoxide. DSB conversion was ∼1-4% of the total non-DSB damage due to gamma rays, which was lower than the 10% estimate by experimental measurement. Five to twenty percent of total non-DSB damage due to helium ions was converted into DSBs. Hence, it may be possible to increase the yields of DSBs in cancerous cells through DNA repair pathways, ultimately enhancing cell killing.
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Affiliation(s)
- Ju-Ying Tsai
- Institute of Biotechnology and Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
| | - Fang-Hsin Chen
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Kweishan, Taiwan, Republic of China Radiation Biology Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan, Republic of China
| | - Tsung-Yu Hsieh
- Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, No. 110, Section 1, Chien-Kuo N Road, Taichung, 402, Taiwan, Republic of China
| | - Ya-Yun Hsiao
- Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, No. 110, Section 1, Chien-Kuo N Road, Taichung, 402, Taiwan, Republic of China
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40
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Chatterjee P, Choudhary GS, Alswillah T, Xiong X, Heston WD, Magi-Galluzzi C, Zhang J, Klein EA, Almasan A. The TMPRSS2-ERG Gene Fusion Blocks XRCC4-Mediated Nonhomologous End-Joining Repair and Radiosensitizes Prostate Cancer Cells to PARP Inhibition. Mol Cancer Ther 2015; 14:1896-906. [PMID: 26026052 DOI: 10.1158/1535-7163.mct-14-0865] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 05/19/2015] [Indexed: 11/16/2022]
Abstract
Exposure to genotoxic agents, such as ionizing radiation (IR), produces DNA damage, leading to DNA double-strand breaks (DSB); IR toxicity is augmented when the DNA repair is impaired. We reported that radiosensitization by a PARP inhibitor (PARPi) was highly prominent in prostate cancer cells expressing the TMPRSS2-ERG gene fusion protein. Here, we show that TMPRSS2-ERG blocks nonhomologous end-joining (NHEJ) DNA repair by inhibiting DNA-PKcs. VCaP cells, which harbor TMPRSS2-ERG and PC3 cells that stably express it, displayed γH2AX and 53BP1 foci constitutively, indicating persistent DNA damage that was absent if TMPRSS2-ERG was depleted by siRNA in VCaP cells. The extent of DNA damage was enhanced and associated with TMPRSS2-ERG's ability to inhibit DNA-PKcs function, as indicated by its own phosphorylation (Thr2609, Ser2056) and that of its substrate, Ser1778-53BP1. DNA-PKcs deficiency caused by TMPRSS2-ERG destabilized critical NHEJ components on chromatin. Thus, XRCC4 was not recruited to chromatin, with retention of other NHEJ core factors being reduced. DNA-PKcs autophosphorylation was restored to the level of parental cells when TMPRSS2-ERG was depleted by siRNA. Following IR, TMPRSS2-ERG-expressing PC3 cells had elevated Rad51 foci and homologous recombination (HR) activity, indicating that HR compensated for defective NHEJ in these cells, hence addressing why TMPRSS2-ERG alone did not lead to radiosensitization. However, the presence of TMPRSS2-ERG, by inhibiting NHEJ DNA repair, enhanced PARPi-mediated radiosensitization. IR in combination with PARPi resulted in enhanced DNA damage in TMPRSS2-ERG-expressing cells. Therefore, by inhibiting NHEJ, TMPRSS2-ERG provides a synthetic lethal interaction with PARPi in prostate cancer patients expressing TMPRSS2-ERG.
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Affiliation(s)
- Payel Chatterjee
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio. School of Biomedical Sciences, Kent State University, Kent, Ohio
| | - Gaurav S Choudhary
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio. Department of Pathology, Case Western Reserve University School of Medicine, Ohio
| | | | - Xiahui Xiong
- Department of Radiation Oncology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Warren D Heston
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Cristina Magi-Galluzzi
- Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio. Robert J. Tomisch Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, Ohio
| | - Junran Zhang
- Department of Radiation Oncology, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Eric A Klein
- Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio
| | - Alexandru Almasan
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio. Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio.
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41
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Dobbelstein M, Sørensen CS. Exploiting replicative stress to treat cancer. Nat Rev Drug Discov 2015; 14:405-23. [PMID: 25953507 DOI: 10.1038/nrd4553] [Citation(s) in RCA: 215] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
DNA replication in cancer cells is accompanied by stalling and collapse of the replication fork and signalling in response to DNA damage and/or premature mitosis; these processes are collectively known as 'replicative stress'. Progress is being made to increase our understanding of the mechanisms that govern replicative stress, thus providing ample opportunities to enhance replicative stress for therapeutic purposes. Rather than trying to halt cell cycle progression, cancer therapeutics could aim to increase replicative stress by further loosening the checkpoints that remain available to cancer cells and ultimately inducing the catastrophic failure of proliferative machineries. In this Review, we outline current and future approaches to achieve this, emphasizing the combination of conventional chemotherapy with targeted approaches.
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Affiliation(s)
- Matthias Dobbelstein
- Institute of Molecular Oncology, Göttingen Center of Molecular Biosciences, Ernst Caspari Haus, University of Göttingen, 37077 Göttingen, Germany
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42
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Kotsantis P, Jones RM, Higgs MR, Petermann E. Cancer therapy and replication stress: forks on the road to perdition. Adv Clin Chem 2015; 69:91-138. [PMID: 25934360 DOI: 10.1016/bs.acc.2014.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Deregulated DNA replication occurs in cancer where it contributes to genomic instability. This process is a target of cytotoxic therapies. Chemotherapies exploit high DNA replication in cancer cells by modifying the DNA template or by inhibiting vital enzymatic activities that lead to slowing or stalling replication fork progression. Stalled replication forks can be converted into toxic DNA double-strand breaks resulting in cell death, i.e., replication stress. While likely crucial for many cancer treatments, replication stress is poorly understood due to its complexity. While we still know relatively little about the role of replication stress in cancer therapy, technical advances in recent years have shed new light on the effect that cancer therapeutics have on replication forks and the molecular mechanisms that lead from obstructed fork progression to cell death. This chapter will give an overview of our current understanding of replication stress in the context of cancer therapy.
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Affiliation(s)
- Panagiotis Kotsantis
- School of Cancer Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Rebecca M Jones
- School of Cancer Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Martin R Higgs
- School of Cancer Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Eva Petermann
- School of Cancer Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
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43
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Xiong X, Du Z, Wang Y, Feng Z, Fan P, Yan C, Willers H, Zhang J. 53BP1 promotes microhomology-mediated end-joining in G1-phase cells. Nucleic Acids Res 2015; 43:1659-70. [PMID: 25586219 PMCID: PMC4330367 DOI: 10.1093/nar/gku1406] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Alternative non-homologous end joining (alt-NHEJ) was originally identified as a backup repair mechanism in the absence of classical NHEJ (c-NHEJ) factors but recent studies have demonstrated that alt-NHEJ is active even when c-NHEJ as well as homologous recombination is available. The functions of 53BP1 in NHEJ processes are not well understood. Here, we report that 53BP1 promotes DNA double-strand break (DSB) repair and genomic stability not only in c-NHEJ-proficient but also -deficient human G1-phase cells. Using an array of repair substrates we show that these effects of 53BP1 are correlated with a promotion of microhomology-mediated end-joining (MMEJ), a subtype of alt-NHEJ, in G1-phase. Consistent with a specific role in MMEJ we confirm that 53BP1 status does not affect c-NHEJ. 53BP1 supports sequence deletion during MMEJ consistent with a putative role in facilitating end-resection. Interestingly, promotion of MMEJ by 53BP1 in G1-phase cells is only observed in the presence of functional BRCA1. Depletion of both 53BP1 and BRCA1 increases repair needing microhomology usage and augments loss of DNA sequence, suggesting that MMEJ is a highly regulated DSB repair process. Together, these findings significantly expand our understanding of the cell-cycle-dependent roles of 53BP1 in DSB repair.
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Affiliation(s)
- Xiahui Xiong
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, BRB 323, Cleveland, OH 44106, USA
| | - Zhanwen Du
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, BRB 323, Cleveland, OH 44106, USA
| | - Ying Wang
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, BRB 323, Cleveland, OH 44106, USA
| | - Zhihui Feng
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, BRB 323, Cleveland, OH 44106, USA
| | - Pan Fan
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine,1650 Orleans Street, Baltimore, MD 21231, USA
| | - Chunhong Yan
- Department of Biochemistry and Molecular Biology, Georgia Regents University, 1410 Laney Walker Blvd., CN-2134, Augusta, GA 30912, USA
| | - Henning Willers
- Department of Radiation Oncology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Junran Zhang
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, BRB 323, Cleveland, OH 44106, USA
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Shen B, Zhao K, Ma S, Yuan D, Bai Y. Topotecan-Loaded Mesoporous Silica Nanoparticles for Reversing Multi-Drug Resistance by Synergetic Chemoradiotherapy. Chem Asian J 2014; 10:344-8. [DOI: 10.1002/asia.201403117] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Indexed: 12/30/2022]
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Han J, Won EJ, Kim IC, Yim JH, Lee SJ, Lee JS. Sublethal gamma irradiation affects reproductive impairment and elevates antioxidant enzyme and DNA repair activities in the monogonont rotifer Brachionus koreanus. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2014; 155:101-109. [PMID: 25000471 DOI: 10.1016/j.aquatox.2014.06.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/13/2014] [Accepted: 06/17/2014] [Indexed: 06/03/2023]
Abstract
To examine the effects of gamma radiation on marine organisms, we irradiated several doses of gamma ray to the microzooplankton Brachionus koreanus, and measured in vivo and in vitro endpoints including the survival rate, lifespan, fecundity, population growth, gamma ray-induced oxidative stress, and modulated patterns of enzyme activities and gene expressions after DNA damage. After gamma radiation, no individuals showed any mortality within 96 h even at a high intensity (1200 Gy). However, a reduced fecundity (e.g. cumulated number of offspring) of B. koreanus at over 150 Gy was observed along with a slight decrease in lifespan. At 150 Gy and 200 Gy, the reduced fecundity of the rotifers led to a significant decrease in population growth, although in the second generation the population growth pattern was not affected even at 200 Gy when compared to the control group. At sub-lethal doses, reactive oxygen species (ROS) levels dose-dependently increased with GST enzyme activity. In addition, up-regulations of the antioxidant and chaperoning genes in response to gamma radiation were able to recover cellular damages, and life table parameters were significantly influenced, particularly with regard to fecundity. DNA repair-associated genes showed significantly up-regulated expression patterns in response to sublethal doses (150 and 200 Gy), as shown in the expression of the gamma-irradiated B. koreanus p53 gene, suggesting that these sublethal doses were not significantly fatal to B. koreanus but induced DNA damages leading to a decrease of the population size.
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Affiliation(s)
- Jeonghoon Han
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746, South Korea
| | - Eun-Ji Won
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746, South Korea
| | - Il-Chan Kim
- Division of Life Sciences, Korea Polar Research Institute, Incheon 406-840, South Korea
| | - Joung Han Yim
- Division of Life Sciences, Korea Polar Research Institute, Incheon 406-840, South Korea
| | - Su-Jae Lee
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791, South Korea
| | - Jae-Seong Lee
- Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746, South Korea.
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Helleday T, Eshtad S, Nik-Zainal S. Mechanisms underlying mutational signatures in human cancers. Nat Rev Genet 2014; 15:585-98. [PMID: 24981601 DOI: 10.1038/nrg3729] [Citation(s) in RCA: 561] [Impact Index Per Article: 56.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The collective somatic mutations observed in a cancer are the outcome of multiple mutagenic processes that have been operative over the lifetime of a patient. Each process leaves a characteristic imprint--a mutational signature--on the cancer genome, which is defined by the type of DNA damage and DNA repair processes that result in base substitutions, insertions and deletions or structural variations. With the advent of whole-genome sequencing, researchers are identifying an increasing array of these signatures. Mutational signatures can be used as a physiological readout of the biological history of a cancer and also have potential use for discerning ongoing mutational processes from historical ones, thus possibly revealing new targets for anticancer therapies.
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Affiliation(s)
- Thomas Helleday
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Saeed Eshtad
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 21 Stockholm, Sweden
| | - Serena Nik-Zainal
- 1] Wellcome Trust Sanger Institute, Hinxton Genome Campus, Cambridge CB10 1SA, UK. [2] East Anglian Medical Genetics Service, Cambridge University Hospitals NHS Trust, Cambridge CB2 2QQ, UK
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Ensminger M, Iloff L, Ebel C, Nikolova T, Kaina B, Lӧbrich M. DNA breaks and chromosomal aberrations arise when replication meets base excision repair. ACTA ACUST UNITED AC 2014; 206:29-43. [PMID: 24982429 PMCID: PMC4085701 DOI: 10.1083/jcb.201312078] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
DNA double-strand breaks and chromosomal aberrations after treatment with N-alkylating agents likely arise as a result of replication fork collision with single-strand breaks generated during base excision repair. Exposures that methylate DNA potently induce DNA double-strand breaks (DSBs) and chromosomal aberrations, which are thought to arise when damaged bases block DNA replication. Here, we demonstrate that DNA methylation damage causes DSB formation when replication interferes with base excision repair (BER), the predominant pathway for repairing methylated bases. We show that cells defective in the N-methylpurine DNA glycosylase, which fail to remove N-methylpurines from DNA and do not initiate BER, display strongly reduced levels of methylation-induced DSBs and chromosomal aberrations compared with wild-type cells. Also, cells unable to generate single-strand breaks (SSBs) at apurinic/apyrimidinic sites do not form DSBs immediately after methylation damage. In contrast, cells deficient in x-ray cross-complementing protein 1, DNA polymerase β, or poly (ADP-ribose) polymerase 1 activity, all of which fail to seal SSBs induced at apurinic/apyrimidinic sites, exhibit strongly elevated levels of methylation-induced DSBs and chromosomal aberrations. We propose that DSBs and chromosomal aberrations after treatment with N-alkylators arise when replication forks collide with SSBs generated during BER.
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Affiliation(s)
- Michael Ensminger
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Lucie Iloff
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Christian Ebel
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
| | - Teodora Nikolova
- Institute of Toxicology, Medical Center of the University Mainz, 55131 Mainz, Germany
| | - Bernd Kaina
- Institute of Toxicology, Medical Center of the University Mainz, 55131 Mainz, Germany
| | - Markus Lӧbrich
- Radiation Biology and DNA Repair, Darmstadt University of Technology, 64287 Darmstadt, Germany
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Abbas M, Shanmugam I, Bsaili M, Hromas R, Shaheen M. The role of the human psoralen 4 (hPso4) protein complex in replication stress and homologous recombination. J Biol Chem 2014; 289:14009-19. [PMID: 24675077 DOI: 10.1074/jbc.m113.520056] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Psoralen 4 (Pso4) is an evolutionarily conserved protein that has been implicated in a variety of cellular processes including RNA splicing and resistance to agents that cause DNA interstrand cross-links. Here we show that the hPso4 complex is required for timely progression through S phase and transition through the G2/M checkpoint, and it functions in the repair of DNA lesions that arise during replication. Notably, hPso4 depletion results in delayed resumption of DNA replication after hydroxyurea-induced stalling of replication forks, reduced repair of spontaneous and hydroxyurea-induced DNA double strand breaks (DSBs), and increased sensitivity to a poly(ADP-ribose) polymerase inhibitor. Furthermore, we show that hPso4 is involved in the repair of DSBs by homologous recombination, probably by regulating the BRCA1 protein levels and the generation of single strand DNA at DSBs. Together, our results demonstrate that hPso4 participates in cell proliferation and the maintenance of genome stability by regulating homologous recombination. The involvement of hPso4 in the recombinational repair of DSBs provides an explanation for the sensitivity of Pso4-deficient cells to DNA interstrand cross-links.
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Affiliation(s)
- Mohammad Abbas
- From the Division of Hematology-Oncology, Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico 87131 and
| | - Ilanchezhian Shanmugam
- From the Division of Hematology-Oncology, Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico 87131 and
| | - Manal Bsaili
- From the Division of Hematology-Oncology, Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico 87131 and
| | - Robert Hromas
- the Department of Medicine, University of Florida, Gainesville, Florida 32611
| | - Monte Shaheen
- From the Division of Hematology-Oncology, Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico 87131 and
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Abstract
Chemoradiation is the standard therapy for the majority of inoperable, locally advanced cancers. Although there is a need to improve chemoradiation efficacy, normal-tissue toxicity limits our ability to give additional chemotherapy or higher doses of radiation. Thus, there is excitement about the addition of molecularly targeted agents, which tend to be less toxic than chemotherapy, to chemoradiation regimens. Unfortunately, initial empiric attempts have not been successful. This review will focus on the evidence that supports rational combinations of targeted agents with chemoradiation, with an emphasis on agents that target the DNA damage response and radiation-induced membrane signaling.
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Affiliation(s)
- Meredith A. Morgan
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI
| | - Leslie A. Parsels
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI
| | - Jonathan Maybaum
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI
| | - Theodore S. Lawrence
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI
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50
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Ramaekers CHMA, van den Beucken T, Bristow RG, Chiu RK, Durocher D, Wouters BG. RNF8-independent Lys63 poly-ubiquitylation prevents genomic instability in response to replication-associated DNA damage. PLoS One 2014; 9:e89997. [PMID: 24587176 PMCID: PMC3938561 DOI: 10.1371/journal.pone.0089997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 01/28/2014] [Indexed: 01/19/2023] Open
Abstract
The cellular response to DNA double strand breaks (DSBs) involves the ordered assembly of repair proteins at or near sites of damage. This process is mediated through post-translational protein modifications that include both phosphorylation and ubiquitylation. Recent data have demonstrated that recruitment of the repair proteins BRCA1, 53BP1, and RAD18 to ionizing irradiation (IR) induced DSBs is dependent on formation of non-canonical K63-linked polyubiquitin chains by the RNF8 and RNF168 ubiquitin ligases. Here we report a novel role for K63-ubiquitylation in response to replication-associated DSBs that contributes to both cell survival and maintenance of genome stability. Suppression of K63-ubiquitylation markedly increases large-scale mutations and chromosomal aberrations in response to endogenous or exogenous replication-associated DSBs. These effects are associated with an S-phase specific defect in DNA repair as revealed by an increase in residual 53BP1 foci. Use of both knockdown and knockout cell lines indicates that unlike the case for IR-induced DSBs, the requirement for K63-ubiquitylation for the repair of replication associated DSBs was found to be RNF8-independent. Our findings reveal the existence of a novel K63-ubiquitylation dependent repair pathway that contributes to the maintenance of genome integrity in response to replication-associated DSBs.
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Affiliation(s)
- Chantal H. M. A. Ramaekers
- Ontario Cancer Institute and Campbell Family Institute for Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
- Maastricht Radiation Oncology (MaastRO) Lab, GROW – School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
| | - Twan van den Beucken
- Ontario Cancer Institute and Campbell Family Institute for Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
- Maastricht Radiation Oncology (MaastRO) Lab, GROW – School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
| | - Robert G. Bristow
- Ontario Cancer Institute and Campbell Family Institute for Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
- Departments of Radiation Oncology and Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Roland K. Chiu
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Daniel Durocher
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Bradly G. Wouters
- Ontario Cancer Institute and Campbell Family Institute for Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
- Maastricht Radiation Oncology (MaastRO) Lab, GROW – School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
- Departments of Radiation Oncology and Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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