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Dong J, Wang C, Zhang T, Yu X, Peng H, Xiao Z, Wang Z, Wen B. Establishment and Application of Novel Hypoxia-driven Dual-reporter Model to Investigate Hypoxic Impact on Radiation Sensitivity in Human Nasopharyngeal Carcinoma Xenografts. J Cancer 2024; 15:4345-4359. [PMID: 38947402 PMCID: PMC11212076 DOI: 10.7150/jca.96378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 05/20/2024] [Indexed: 07/02/2024] Open
Abstract
Background: Tumor hypoxia has been frequently detected in nasopharyngeal carcinoma (NPC) and is intently associated with therapeutic resistance. The aim of the study is to establish a clonogenically stable hypoxia-inducible dual reporter model and apply it to investigate the effect of tumor hypoxia on DNA double strand break (DSB) and synergistic effect of irradiation in combination with chemotherapy or targeted therapy. Methods: The plasmid vector consisting of hypoxia response elements to regulate HSV1-TK and GFP genes, was constructed and stably transfected into human NPC cells. The expected clone was identified and validated by in vivo and in vitro assay. DSB repair was measured by γH2AX foci formation. Tumor growth delay assay and spatial biodistribution of various biomarkers was designed to investigate the anti-tumor effect. Results: The system has the propensity of high expression of reporter genes under hypoxia and low to no expression under normoxia. Intratumoral biodistributions of GFP and classic hypoxic biomarkers were identical in poor-perfused region. Upon equilibration with 10% O2, the xenografts showed higher expression of hypoxic biomarkers. Cisplatin radiosensitized SUNE-1/HRE cells under hypoxia by suppressing DSB repair while the addition of PI3K/mTOR inhibitor further enhanced the anti-tumoral therapeutic efficacy. Combination of IR, DDP and NVP-BEZ235 exhibited most effective anti-tumor response in vivo. These observations underline the importance of dual reporter model for imaging tumor hypoxia in therapeutic study. Conclusions: Our preclinical model enables the investigation of heterogeneous tumor hypoxic regions in xenograft tissues and explores the treatment efficacy of combinations of various therapeutic approaches to overcome hypoxia.
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Affiliation(s)
- Jun Dong
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, 510080, China
- Department of Clinical Oncology, The University of Hong Kong-Shenzhen Hospital, Shenzhen, Guangdong Province, 518048, China
| | - Chengtao Wang
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, 510080, China
| | - Tian Zhang
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, 510080, China
- Department of Radiation Oncology, The Fifth Affiliated Hospital, Sun Yat-sen University. Zhuhai, Guangdong, 519000, China
| | - Xiaobi Yu
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, 510080, China
| | - Haihua Peng
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, 510080, China
- Department of Radiation Oncology, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, Guangdong Province, 510075, China
| | - Zhenhua Xiao
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, 510080, China
| | - Zhenyu Wang
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, 510080, China
| | - Bixiu Wen
- Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, 510080, China
- Department of Medical Physics and Radiation Oncology, Memorial Sloan-Kettering Cancer Center, NY, New York City, 10021, USA
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Sriramulu S, Thoidingjam S, Chen WM, Hassan O, Siddiqui F, Brown SL, Movsas B, Green MD, Davis AJ, Speers C, Walker E, Nyati S. BUB1 regulates non-homologous end joining pathway to mediate radioresistance in triple-negative breast cancer. J Exp Clin Cancer Res 2024; 43:163. [PMID: 38863037 PMCID: PMC11167950 DOI: 10.1186/s13046-024-03086-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 05/30/2024] [Indexed: 06/13/2024] Open
Abstract
BACKGROUND Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer subtype often treated with radiotherapy (RT). Due to its intrinsic heterogeneity and lack of effective targets, it is crucial to identify novel molecular targets that would increase RT efficacy. Here we demonstrate the role of BUB1 (cell cycle Ser/Thr kinase) in TNBC radioresistance and offer a novel strategy to improve TNBC treatment. METHODS Gene expression analysis was performed to look at genes upregulated in TNBC patient samples compared to other subtypes. Cell proliferation and clonogenic survivals assays determined the IC50 of BUB1 inhibitor (BAY1816032) and radiation enhancement ratio (rER) with pharmacologic and genomic BUB1 inhibition. Mammary fat pad xenografts experiments were performed in CB17/SCID. The mechanism through which BUB1 inhibitor sensitizes TNBC cells to radiotherapy was delineated by γ-H2AX foci assays, BLRR, Immunoblotting, qPCR, CHX chase, and cell fractionation assays. RESULTS BUB1 is overexpressed in BC and its expression is considerably elevated in TNBC with poor survival outcomes. Pharmacological or genomic ablation of BUB1 sensitized multiple TNBC cell lines to cell killing by radiation, although breast epithelial cells showed no radiosensitization with BUB1 inhibition. Kinase function of BUB1 is mainly accountable for this radiosensitization phenotype. BUB1 ablation also led to radiosensitization in TNBC tumor xenografts with significantly increased tumor growth delay and overall survival. Mechanistically, BUB1 ablation inhibited the repair of radiation-induced DNA double strand breaks (DSBs). BUB1 ablation stabilized phospho-DNAPKcs (S2056) following RT such that half-lives could not be estimated. In contrast, RT alone caused BUB1 stabilization, but pre-treatment with BUB1 inhibitor prevented stabilization (t1/2, ~8 h). Nuclear and chromatin-enriched fractionations illustrated an increase in recruitment of phospho- and total-DNAPK, and KAP1 to chromatin indicating that BUB1 is indispensable in the activation and recruitment of non-homologous end joining (NHEJ) proteins to DSBs. Additionally, BUB1 staining of TNBC tissue microarrays demonstrated significant correlation of BUB1 protein expression with tumor grade. CONCLUSIONS BUB1 ablation sensitizes TNBC cell lines and xenografts to RT and BUB1 mediated radiosensitization may occur through NHEJ. Together, these results highlight BUB1 as a novel molecular target for radiosensitization in women with TNBC.
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Affiliation(s)
- Sushmitha Sriramulu
- Department of Radiation Oncology, Henry Ford Cancer Institute, Henry Ford Health, 1 Ford Place, Detroit, 5D-42, MI-48202, USA
| | - Shivani Thoidingjam
- Department of Radiation Oncology, Henry Ford Cancer Institute, Henry Ford Health, 1 Ford Place, Detroit, 5D-42, MI-48202, USA
| | - Wei-Min Chen
- Department of Radiation Oncology, UT Southwestern Medical School, Dallas, TX-75390, USA
| | - Oudai Hassan
- Department of Surgical Pathology, Henry Ford Cancer Institute, Henry Ford Health, Detroit, MI-48202, USA
| | - Farzan Siddiqui
- Department of Radiation Oncology, Henry Ford Cancer Institute, Henry Ford Health, 1 Ford Place, Detroit, 5D-42, MI-48202, USA
- Henry Ford Health + Michigan State University Health Sciences, Detroit, MI-48202, USA
- Department of Radiology, Michigan State University, East Lansing, MI-48824, USA
| | - Stephen L Brown
- Department of Radiation Oncology, Henry Ford Cancer Institute, Henry Ford Health, 1 Ford Place, Detroit, 5D-42, MI-48202, USA
- Henry Ford Health + Michigan State University Health Sciences, Detroit, MI-48202, USA
- Department of Radiology, Michigan State University, East Lansing, MI-48824, USA
| | - Benjamin Movsas
- Department of Radiation Oncology, Henry Ford Cancer Institute, Henry Ford Health, 1 Ford Place, Detroit, 5D-42, MI-48202, USA
- Henry Ford Health + Michigan State University Health Sciences, Detroit, MI-48202, USA
- Department of Radiology, Michigan State University, East Lansing, MI-48824, USA
| | - Michael D Green
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI-48109, USA
| | - Anthony J Davis
- Department of Radiation Oncology, UT Southwestern Medical School, Dallas, TX-75390, USA
| | - Corey Speers
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI-48109, USA
- Department of Radiation Oncology, UH Seidman Cancer Center, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, OH-44106, USA
| | - Eleanor Walker
- Department of Radiation Oncology, Henry Ford Cancer Institute, Henry Ford Health, 1 Ford Place, Detroit, 5D-42, MI-48202, USA
- Henry Ford Health + Michigan State University Health Sciences, Detroit, MI-48202, USA
- Department of Radiology, Michigan State University, East Lansing, MI-48824, USA
| | - Shyam Nyati
- Department of Radiation Oncology, Henry Ford Cancer Institute, Henry Ford Health, 1 Ford Place, Detroit, 5D-42, MI-48202, USA.
- Henry Ford Health + Michigan State University Health Sciences, Detroit, MI-48202, USA.
- Department of Radiology, Michigan State University, East Lansing, MI-48824, USA.
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3
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Sriramulu S, Thoidingjam S, Chen WM, Hassan O, Siddiqui F, Brown SL, Movsas B, Green MD, Davis AJ, Speers C, Walker E, Nyati S. BUB1 regulates non-homologous end joining pathway to mediate radioresistance in triple-negative breast cancer. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.07.592812. [PMID: 38766122 PMCID: PMC11100764 DOI: 10.1101/2024.05.07.592812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Background Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer subtype often treated with radiotherapy (RT). Due to its intrinsic heterogeneity and lack of effective targets, it is crucial to identify novel molecular targets that would increase RT efficacy. Here we demonstrate the role of BUB1 (cell cycle Ser/Thr kinase) in TNBC radioresistance and offer a novel strategy to improve TNBC treatment. Methods Gene expression analysis was performed to look at genes upregulated in TNBC patient samples compared to other subtypes. Cell proliferation and clonogenic survivals assays determined the IC 50 of BUB1 inhibitor (BAY1816032) and radiation enhancement ratio (rER) with pharmacologic and genomic BUB1 inhibition. Mammary fat pad xenografts experiments were performed in CB17/SCID. The mechanism through which BUB1 inhibitor sensitizes TNBC cells to radiotherapy was delineated by γ-H2AX foci assays, BLRR, Immunoblotting, qPCR, CHX chase, and cell fractionation assays. Results BUB1 is overexpressed in BC and its expression is considerably elevated in TNBC with poor survival outcomes. Pharmacological or genomic ablation of BUB1 sensitized multiple TNBC cell lines to cell killing by radiation, although breast epithelial cells showed no radiosensitization with BUB1 inhibition. Kinase function of BUB1 is mainly accountable for this radiosensitization phenotype. BUB1 ablation also led to radiosensitization in TNBC tumor xenografts with significantly increased tumor growth delay and overall survival. Mechanistically, BUB1 ablation inhibited the repair of radiation-induced DNA double strand breaks (DSBs). BUB1 ablation stabilized phospho-DNAPKcs (S2056) following RT such that half-lives could not be estimated. In contrast, RT alone caused BUB1 stabilization, but pre-treatment with BUB1 inhibitor prevented stabilization (t 1/2 , ∼8 h). Nuclear and chromatin-enriched fractionations illustrated an increase in recruitment of phospho- and total-DNAPK, and KAP1 to chromatin indicating that BUB1 is indispensable in the activation and recruitment of non-homologous end joining (NHEJ) proteins to DSBs. Additionally, BUB1 staining of TNBC tissue microarrays demonstrated significant correlation of BUB1 protein expression with tumor grade. Conclusions BUB1 ablation sensitizes TNBC cell lines and xenografts to RT and BUB1 mediated radiosensitization may occur through NHEJ. Together, these results highlight BUB1 as a novel molecular target for radiosensitization in women with TNBC.
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Lütge A, Lu J, Hüllein J, Walther T, Sellner L, Wu B, Rosenquist R, Oakes CC, Dietrich S, Huber W, Zenz T. Subgroup-specific gene expression profiles and mixed epistasis in chronic lymphocytic leukemia. Haematologica 2023; 108:2664-2676. [PMID: 37226709 PMCID: PMC10614035 DOI: 10.3324/haematol.2022.281869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 05/18/2023] [Indexed: 05/26/2023] Open
Abstract
Understanding the molecular and phenotypic heterogeneity of cancer is a prerequisite for effective treatment. For chronic lymphocytic leukemia (CLL), recurrent genetic driver events have been extensively cataloged, but this does not suffice to explain the disease's diverse course. Here, we performed RNA sequencing on 184 CLL patient samples. Unsupervised analysis revealed two major, orthogonal axes of gene expression variation: the first one represented the mutational status of the immunoglobulin heavy variable (IGHV) genes, and concomitantly, the three-group stratification of CLL by global DNA methylation. The second axis aligned with trisomy 12 status and affected chemokine, MAPK and mTOR signaling. We discovered non-additive effects (epistasis) of IGHV mutation status and trisomy 12 on multiple phenotypes, including the expression of 893 genes. Multiple types of epistasis were observed, including synergy, buffering, suppression and inversion, suggesting that molecular understanding of disease heterogeneity requires studying such genetic events not only individually but in combination. We detected strong differentially expressed gene signatures associated with major gene mutations and copy number aberrations including SF3B1, BRAF and TP53, as well as del(17)(p13), del(13)(q14) and del(11)(q22.3) beyond dosage effect. Our study reveals previously underappreciated gene expression signatures for the major molecular subtypes in CLL and the presence of epistasis between them.
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Affiliation(s)
- Almut Lütge
- Genome Biology Unit, EMBL, Heidelberg, Germany; Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland; SIB Swiss Institute of Bioinformatics, University of Zurich, Zurich
| | - Junyan Lu
- Genome Biology Unit, EMBL, Heidelberg, Germany; Medical Faculty Heidelberg, Heidelberg University, Heidelberg
| | | | - Tatjana Walther
- Molecular Therapy in Hematology and Oncology and Department of Translational Oncology, NCT and DKFZ, Heidelberg
| | - Leopold Sellner
- Molecular Therapy in Hematology and Oncology and Department of Translational Oncology, NCT and DKFZ, Heidelberg, Germany; Department of Medicine V, Heidelberg University Hospital, Heidelberg
| | - Bian Wu
- Molecular Therapy in Hematology and Oncology and Department of Translational Oncology, NCT and DKFZ, Heidelberg, Germany; Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan
| | - Richard Rosenquist
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Clinical Genetics, Karolinska University Hospital, Solna
| | - Christopher C Oakes
- Department of Internal Medicine, Division of Hematology, The Ohio State University, Columbus
| | - Sascha Dietrich
- Department of Medicine V, Heidelberg University Hospital, Heidelberg
| | | | - Thorsten Zenz
- Molecular Therapy in Hematology and Oncology and Department of Translational Oncology, NCT and DKFZ, Heidelberg, Germany; Department of Medical Oncology and Hematology, University Hospital Zurich, Zurich.
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5
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Bright SJ, Flint DB, Martinus DKJ, Turner BX, Manandhar M, Ben Kacem M, McFadden CH, Yap TA, Shaitelman SF, Sawakuchi GO. Targeted Inhibition of DNA-PKcs, ATM, ATR, PARP, and Rad51 Modulate Response to X Rays and Protons. Radiat Res 2022; 198:336-346. [PMID: 35939823 PMCID: PMC9648665 DOI: 10.1667/rade-22-00040.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 07/05/2022] [Indexed: 11/03/2022]
Abstract
Small molecule inhibitors are currently in preclinical and clinical development for the treatment of selected cancers, particularly those with existing genetic alterations in DNA repair and DNA damage response (DDR) pathways. Keen interest has also been expressed in combining such agents with other targeted antitumor strategies such as radiotherapy. Radiotherapy exerts its cytotoxic effects primarily through DNA damage-induced cell death; therefore, inhibiting DNA repair and the DDR should lead to additive and/or synergistic radiosensitizing effects. In this study we screened the response to X-ray or proton radiation in cell lines treated with DDR inhibitors (DDRis) targeting ATM, ATR, DNA-PKcs, Rad51, and PARP, with survival metrics established using clonogenic assays. We observed that DDRis generate significant radiosensitization in cancer and primary cells derived from normal tissue. Existing genetic defects in cancer cells appear to be an important consideration when determining the optimal inhibitor to use for synergistic combination with radiation. We also show that while greater radiosensitization can be achieved with protons (9.9 keV/µm) combined with DDRis, the relative biological effectiveness is unchanged or in some cases reduced. Our results indicate that while targeting the DDR can significantly radiosensitize cancer cells to such combinations, normal cells may also be equally or more severely affected, depending on the DDRi used. These data highlight the importance of identifying genetic defects as predictive biomarkers of response for combination treatment.
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Affiliation(s)
- Scott J. Bright
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - David B. Flint
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - David K. J. Martinus
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas
| | - Broderick X. Turner
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas
| | - Mandira Manandhar
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Mariam Ben Kacem
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Conor H. McFadden
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Timothy A. Yap
- Department of Investigational Cancer Therapeutics (Phase I Clinical Trials Program), Division of Cancer Medicine; Khalifa Institute for Personalized Cancer Therapy; Department of Thoracic/Head and Neck Medical Oncology; and The Institute for Applied Cancer Science. The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Simona F. Shaitelman
- Department of Radiation Oncology, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Gabriel O. Sawakuchi
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas
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Lung Cancer Targeted Chemoradiotherapy via Dual-Stimuli Responsive Biodegradable Core-Shell Nanoparticles. Pharmaceutics 2022; 14:pharmaceutics14081525. [PMID: 35893781 PMCID: PMC9332477 DOI: 10.3390/pharmaceutics14081525] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/15/2022] [Accepted: 07/18/2022] [Indexed: 12/28/2022] Open
Abstract
Lung cancer is one of the major causes of cancer-related deaths worldwide, primarily because of the limitations of conventional clinical therapies such as chemotherapy and radiation therapy. Side effects associated with these treatments have made it essential for new modalities, such as tumor targeting nanoparticles that can provide cancer specific therapies. In this research, we have developed novel dual-stimuli nanoparticles (E-DSNPs), comprised of two parts; (1) Core: responsive to glutathione as stimuli and encapsulating Cisplatin (a chemo-drug), and (2) Shell: responsive to irradiation as stimuli and containing NU7441 (a radiation sensitizer). The targeting moieties on these nanoparticles are Ephrin transmembrane receptors A2 (EphA2) that are highly expressed on the surfaces of lung cancer cells. These nanoparticles were then evaluated for their enhanced targeting and therapeutic efficiency against lung cancer cell lines. E-DSNPs displayed very high uptake by lung cancer cells compared to healthy lung epithelial cells. These nanoparticles also demonstrated a triggered release of both drugs against respective stimuli and a subsequent reduction in in vitro cancer cell survival fraction compared to free drugs of equivalent concentration (survival fraction of about 0.019 and 0.19, respectively). Thus, these nanoparticles could potentially pave the path to targeted cancer therapy, while overcoming the side effects of conventional clinical therapies.
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Zaharieva EK, Sasatani M, Kamiya K. Kinetics of DNA Repair Under Chronic Irradiation at Low and Medium Dose Rates in Repair Proficient and Repair Compromised Normal Fibroblasts. Radiat Res 2021; 197:332-349. [PMID: 34958666 DOI: 10.1667/rade-21-00158.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 11/17/2021] [Indexed: 11/03/2022]
Abstract
We present time and dose dependencies for the formation of 53BP1 and γH2AX DNA damage repair foci after chronic radiation exposure at dose rates of 140, 250 and 450 mGy/day from 3 to 96 h, in human and mouse repair proficient and ATM or DNA-PK deficient repair compromised cell models. We describe the time/dose-response curves using a mathematical equation which contains a linear component for the induction of DNA damage repair foci after irradiation, and an exponential component for their resolution. We show that under conditions of chronic irradiation at low and medium dose rates, the processes of DNA double-strand breaks (DSBs) induction and repair establish an equilibrium, which in repair proficient cells manifests as a plateau-shaped dose-response where the plateau is reached within the first 24 h postirradiation, and its height is proportionate to the radiation dose rate. In contrast, in repair compromised cells, where the rate of repair may be exceeded by the DSB induction rate, DNA damage accumulates with time of exposure and total absorbed dose. In addition, we discuss the biological meaning of the observed dependencies by presenting the frequency of micronuclei formation under the same irradiation conditions as a marker of radiation-induced genomic instability. We believe that the data and analysis presented here shed light on the kinetics of DNA repair under chronic radiation and are useful for future studies in the low-to-medium dose rate range.
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Affiliation(s)
- Elena K Zaharieva
- Department of Experimental Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - Megumi Sasatani
- Department of Experimental Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
| | - Kenji Kamiya
- Department of Experimental Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan
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Cardinale A, Saladini S, Lupacchini L, Ruspantini I, De Dominicis C, Papale M, Silvagno F, Garaci E, Mollinari C, Merlo D. DNA repair protein DNA-PK protects PC12 cells from oxidative stress-induced apoptosis involving AKT phosphorylation. Mol Biol Rep 2021; 49:1089-1101. [PMID: 34797489 PMCID: PMC8825611 DOI: 10.1007/s11033-021-06934-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 11/05/2021] [Indexed: 11/30/2022]
Abstract
Background Emerging evidence suggest that DNA-PK complex plays a role in the cellular response to oxidative stress, in addition to its function of double strand break (DSB) repair. In this study we evaluated whether DNA-PK participates in oxidative stress response and whether this role is independent of its function in DNA repair. Methods and results We used a model of H2O2-induced DNA damage in PC12 cells (rat pheochromocytoma), a well-known neuronal tumor cell line. We found that H2O2 treatment of PC12 cells induces an increase in DNA-PK protein complex levels, along with an elevation of DNA damage, measured both by the formation of γΗ2ΑX foci, detected by immunofluorescence, and γH2AX levels detected by western blot analysis. After 24 h of cell recovery, γΗ2ΑX foci are repaired both in the absence and presence of DNA-PK kinase inhibitor NU7026, while an increase of apoptotic cells is observed when DNA-PK activity is inhibited, as revealed by counting pycnotic nuclei and confirmed by FACS analysis. Our results suggest a role of DNA-PK as an anti-apoptotic factor in proliferating PC12 cells under oxidative stress conditions. The anti-apoptotic role of DNA-PK is associated with AKT phosphorylation in Ser473. On the contrary, in differentiated PC12 cells, were the main pathway to repair DSBs is DNA-PK-mediated, the inhibition of DNA-PK activity causes an accumulation of DNA damage. Conclusions Taken together, our results show that DNA-PK can protect cells from oxidative stress induced-apoptosis independently from its function of DSB repair enzyme. Graphical Abstract ![]()
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Affiliation(s)
- Alessio Cardinale
- Molecular and Cellular Neurobiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166, Rome, Italy
| | - Serena Saladini
- Molecular and Cellular Neurobiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166, Rome, Italy
| | - Leonardo Lupacchini
- Molecular and Cellular Neurobiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166, Rome, Italy
| | - Irene Ruspantini
- FAST. Istituto Superiore di Sanita', Viale Regina Elena 299, 00161, Rome, Italy
| | - Chiara De Dominicis
- Molecular and Cellular Neurobiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166, Rome, Italy.,Department of Neuroscience, Istituto Superiore di Sanita', Viale Regina Elena 299, 00161, Rome, Italy
| | - Marco Papale
- Molecular and Cellular Neurobiology, IRCCS San Raffaele Roma, Via di Val Cannuta 247, 00166, Rome, Italy
| | - Francesca Silvagno
- Department of Oncology, University Torino, via Santena 5 bis, 10126, Torino, Italy
| | - Enrico Garaci
- University San Raffaele, Via di Val Cannuta 247, 00166, Rome, Italy
| | - Cristiana Mollinari
- Department of Neuroscience, Istituto Superiore di Sanita', Viale Regina Elena 299, 00161, Rome, Italy.,Institute of Translational Pharmacology, National Research Council, Via Fosso del Cavaliere 100, 00133, Rome, Italy
| | - Daniela Merlo
- Department of Neuroscience, Istituto Superiore di Sanita', Viale Regina Elena 299, 00161, Rome, Italy.
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Tsakaneli A, Williams O. Drug Repurposing for Targeting Acute Leukemia With KMT2A ( MLL)-Gene Rearrangements. Front Pharmacol 2021; 12:741413. [PMID: 34594227 PMCID: PMC8478155 DOI: 10.3389/fphar.2021.741413] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/01/2021] [Indexed: 12/12/2022] Open
Abstract
The treatment failure rates of acute leukemia with rearrangements of the Mixed Lineage Leukemia (MLL) gene highlight the need for novel therapeutic approaches. Taking into consideration the limitations of the current therapies and the advantages of novel strategies for drug discovery, drug repurposing offers valuable opportunities to identify treatments and develop therapeutic approaches quickly and effectively for acute leukemia with MLL-rearrangements. These approaches are complimentary to de novo drug discovery and have taken advantage of increased knowledge of the mechanistic basis of MLL-fusion protein complex function as well as refined drug repurposing screens. Despite the vast number of different leukemia associated MLL-rearrangements, the existence of common core oncogenic pathways holds the promise that many such therapies will be broadly applicable to MLL-rearranged leukemia as a whole.
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Affiliation(s)
- Alexia Tsakaneli
- Cancer Section, Developmental Biology and Cancer Programme, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Owen Williams
- Cancer Section, Developmental Biology and Cancer Programme, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
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10
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Waldrip ZJ, Burdine L, Harrison DK, Azevedo-Pouly AC, Storey AJ, Moffett OG, Mackintosh SG, Burdine MS. DNA-PKcs kinase activity stabilizes the transcription factor Egr1 in activated immune cells. J Biol Chem 2021; 297:101209. [PMID: 34562454 PMCID: PMC8551498 DOI: 10.1016/j.jbc.2021.101209] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 09/14/2021] [Accepted: 09/16/2021] [Indexed: 11/25/2022] Open
Abstract
DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is known primarily for its function in DNA double-stranded break repair and nonhomologous end joining (NHEJ). However, DNA-PKcs also has a critical yet undefined role in immunity impacting both myeloid and lymphoid cell lineages spurring interest in targeting DNA-PKcs for therapeutic strategies in immune-related diseases. To gain insight into the function of DNA-PKcs within immune cells, we performed a quantitative phosphoproteomic screen in T cells to identify phosphorylation targets of DNA-PKcs. Our results indicate that DNA-PKcs phosphorylates the transcription factor Egr1 (early growth response protein 1) at serine 301. Expression of Egr1 is induced early upon T cell activation and dictates T cell response by modulating expression of cytokines and key costimulatory molecules such as IL (interleukin) 2, IL6, IFNγ, and NFκB. Inhibition of DNA-PKcs by treatment with a DNA-PKcs specific inhibitor NU7441 or shRNA knockdown increased proteasomal degradation of Egr1. Mutation of serine 301 to alanine via CRISPR-Cas9 reduced EGR1 protein expression and decreased Egr1-dependent transcription of IL2 in activated T cells. Our findings identify DNA-PKcs as a critical intermediary link between T cell activation and T cell fate and a novel phosphosite involved in regulating Egr1 activity.
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Affiliation(s)
- Zachary J Waldrip
- Division of Surgical Research, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; Center for Translational Pediatric Research, Arkansas Children's Research Institute, Little Rock, Arkansas, USA
| | - Lyle Burdine
- Division of Surgical Research, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; Department of Transplant Surgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - David K Harrison
- Division of Surgical Research, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; Center for Translational Pediatric Research, Arkansas Children's Research Institute, Little Rock, Arkansas, USA
| | - Ana Clara Azevedo-Pouly
- Division of Surgical Research, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; Center for Translational Pediatric Research, Arkansas Children's Research Institute, Little Rock, Arkansas, USA
| | - Aaron J Storey
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Olivia G Moffett
- College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Samuel G Mackintosh
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Marie Schluterman Burdine
- Division of Surgical Research, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; Center for Translational Pediatric Research, Arkansas Children's Research Institute, Little Rock, Arkansas, USA.
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11
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Testicular Germ Cell Tumors Acquire Cisplatin Resistance by Rebalancing the Usage of DNA Repair Pathways. Cancers (Basel) 2021; 13:cancers13040787. [PMID: 33668653 PMCID: PMC7917736 DOI: 10.3390/cancers13040787] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/27/2021] [Accepted: 02/08/2021] [Indexed: 02/08/2023] Open
Abstract
Simple Summary Germ cell tumors are a model of curable solid tumors due to their unique sensitivity to cisplatin-based chemotherapy. Patients are typically young adults, and despite high cure rate, about 20% of them do not achieve remission or relapse, and 50% of them succumb to the disease. The mechanisms behind their resistance to therapy are largely unknown. By using Testicular Germ Cell Tumor (TGCT) cell lines as a model, we investigated the mechanism of acquired resistance to cisplatin. We demonstrated that resistance occurred by a fine modulation of the DNA repair pathway choice. Namely, in resistant cells, repair of double-strand breaks by non-homologous end joining was dampened by the reduced expression of TP53-binding protein 1 (53BP1) and DNA-dependent protein kinase (DNA-PKcs). However, cisplatin-induced damage was repaired efficiently by homologous recombination. Additionally, we demonstrate that pharmacological inhibition of poly (ADP-ribose) polymerase (PARP) combined with cisplatin had an additive/synergistic effect on cisplatin-resistant cells, which represents the proof of concept for introducing PARP inhibitors in salvage therapy. Abstract Despite germ cell tumors (GCTs) responding to cisplatin-based chemotherapy at a high rate, a subset of patients does not respond to treatment and have significantly worse prognosis. The biological mechanisms underlying the resistance remain unknown. In this study, by using two TGCT cell lines that have acquired cisplatin resistance after chronic exposure to the drug, we identified some key proteins and mechanisms of acquired resistance. We show that cisplatin-resistant cell lines had a non-homologous end-joining (NHEJ)-less phenotype. This correlated with a reduced basal expression of TP53-binding protein 1 (53BP1) and DNA-dependent protein kinase (DNA-PKcs) proteins and reduced formation of 53BP1 foci after cisplatin treatment. Consistent with these observations, modulation of 53BP1 protein expression altered the cell line’s resistance to cisplatin, and inhibition of DNA-PKcs activity antagonized cisplatin cytotoxicity. Dampening of NHEJ was accompanied by a functional increase in the repair of DNA double-strand breaks (DSBs) by the homologous recombination repair pathway. As a result, cisplatin-resistant cells were more resistant to PARP inhibitor (PARPi) monotherapy. Moreover, when PARPi was given in combination with cisplatin, it exerted an additive/synergistic effect, and reduced the cisplatin dose for cytotoxicity. These results suggest that treatment of cisplatin-refractory patients may benefit from low-dose cisplatin therapy combined with PARPi.
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12
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Kopa P, Macieja A, Pastwa E, Majsterek I, Poplawski T. DNA double-strand breaks repair inhibitors potentiates the combined effect of VP-16 and CDDP in human colorectal adenocarcinoma (LoVo) cells. Mol Biol Rep 2021; 48:709-720. [PMID: 33389482 DOI: 10.1007/s11033-020-06124-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 12/22/2020] [Indexed: 12/18/2022]
Abstract
I. BACKGROUND A combination of etoposide (VP-16) and cisplatin (CDDP) is the standard treatment for certain colon cancers. These drugs promote the death of cancer cells via direct and indirect induction of the most lethal DNA lesions - DNA double-stand breaks. However, cancer cells can reverse the DNA damaging effect of anticancer drugs by triggering DNA repair processes. In eukaryotic cells, the main DNA repair pathway responsible for DNA double-stand breaks repair is non-homologous end-joining (NHEJ). Inhibitors of DNA repair are of special interest in cancer research as they could break the cellular resistance to DNA-damaging agents and increase the efficiency of standard cancer treatments. In this study, we investigated the effect of two NHEJ inhibitors, SCR7 and NU7441, on the cytotoxic mechanism of VP-16/CDDP in a LoVo human colorectal adenocarcinoma cell line. SCR7 blocks Ligase IV-mediated joining by interfering with its DNA binding, whereas NU7441 is a highly potent and selective DNA-PK inhibitor.II. METHODS AND RESULTS Both inhibitors synergistically increased the cytotoxicity of CDDP and VP-16 when combined, but the effect of SCR7 was more pronounced. SCR7 and NU7441 also significantly increased VP-16; CDDP induced DNA double-stand breaks level and delayed drug-induced DSB repair, as seen on the comet assay and measured using H2AX foci. We also observed changes in cell cycle distribution and enhanced apoptosis ratio in colorectal adenocarcinoma cells treated with DNA repair inhibitors and VP-16/CDDP.III. CONCLUSIONS Our data support the hypothesis that NHEJ inhibitors could be used in conjunction with standard therapy to provide effective clinical improvement and allow reduction in drug doses.
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Affiliation(s)
- Paulina Kopa
- Faculty of Medicine, Department of Immunopathology, Division of Biomedical Science, Medical University of Lodz, Lodz, Poland
| | - Anna Macieja
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Elzbieta Pastwa
- Functional Genomics & Proteomics Unit, ITSI-Biosciences, Johnstown, PA, USA
| | - Ireneusz Majsterek
- Department of Clinical Chemistry and Biochemistry, Faculty of Medicine, Medical University of Lodz, Lodz, Poland
| | - Tomasz Poplawski
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
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13
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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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14
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Wang G, Guo S, Zhang W, Li Z, Xu J, Li D, Wang Y, Zhan Q. A Comprehensive Analysis of Alterations in DNA Damage Repair Pathways Reveals a Potential Way to Enhance the Radio-Sensitivity of Esophageal Squamous Cell Cancer. Front Oncol 2020; 10:575711. [PMID: 33178606 PMCID: PMC7596747 DOI: 10.3389/fonc.2020.575711] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 09/24/2020] [Indexed: 12/14/2022] Open
Abstract
Esophageal squamous cell cancer (ESCC) is a common malignancy with a poor 5-year overall survival in China. Altered DNA damage repair (DDR) pathways are associated with a predisposition to cancer and contribute to therapeutic response and resistance in cancers. However, alterations of DDR pathway genes in ESCC are still largely unknown. In this study, we employed genome sequencing data of 192 samples, comparative genomic hybridization data of 123 cases, and gene expression microarray data of 119 patients to firstly perform a comprehensive analysis of the gene alterations of 7 DDR pathways in ESCC. Gene mutations and copy number variations (CNVs) were observed in all 7 DDR pathways, and especially, CNVs were the dominant alteration types. Compared with other pathways, two DNA double-strand break (DSB) repair pathways homologous recombination (HR) and non-homologous end joining (NHEJ), carried significant gene mutations and CNVs especially gene amplifications. Most genes including RAD54B, NBS1, RAD51B, and PRKDC were significantly amplified and over-expressed in ESCC. Amplification and high expression of DSB repair pathway genes were associated with poorer overall survival. Gene set variation analysis further showed that DSB repair pathways were up-regulated in ESCC. Besides, we firstly demonstrated that combination of mirin and NU7441, two inhibitors for HR and NHEJ respectively, with ionizing radiation treatment significantly enhanced DSBs, reduced clonogenic cell survival, inhibited cell proliferation, and promoted cell apoptosis in ESCC cells with DSB pathway gene amplification. These findings suggest that DSB repair pathways were significantly altered in ESCC and inhibiting DSB repair pathways might enhance the radio-sensitivity of ESCC with DSB repair up-regulation.
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Affiliation(s)
- Guangchao Wang
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shichao Guo
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Weimin Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Zhangfu Li
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jiancheng Xu
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Dan Li
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yan Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Qimin Zhan
- State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Laboratory of Molecular Oncology, Peking University Cancer Hospital & Institute, Beijing, China
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15
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Dobler C, Jost T, Hecht M, Fietkau R, Distel L. Senescence Induction by Combined Ionizing Radiation and DNA Damage Response Inhibitors in Head and Neck Squamous Cell Carcinoma Cells. Cells 2020; 9:cells9092012. [PMID: 32883016 PMCID: PMC7563880 DOI: 10.3390/cells9092012] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/28/2020] [Accepted: 08/30/2020] [Indexed: 12/18/2022] Open
Abstract
DNA damage response inhibitors (DDRi) may selectively enhance the inactivation of tumor cells in combination with ionizing radiation (IR). The induction of senescence may be the key mechanism of tumor cell inactivation in this combinatorial treatment. In the current study the effect of combined IR with DDRi on the induction of senescence was studied in head and neck squamous cell carcinoma (HNSCC) cells with different human papilloma virus (HPV) status. The integrity of homologous recombination (HR) was assessed in two HPV positive, two HPV negative HNSCC, and two healthy fibroblast cell cultures. Cells were treated with the DDRi CC-115 (DNA-dependent protein kinase, DNA-pK; dual mammalian target of rapamycin, mTor), VE-822 (ATR; ataxia telangiectasia and Rad3-related kinase), and AZD0156 (ATM; ataxia telangiectasia mutated kinase) combined with IR. Effects on senescence, apoptosis, necrosis, and cell cycle were analyzed by flow cytometry. The fibroblast cell lines generally tolerated IR or combined treatment better than the tumor cell lines. The ATM and ATR inhibitors were effectively inducing senescence when combined with IR. The DNA-PK inhibitor was not an important inductor of senescence. HPV status and HR activity had a limited influence on the efficacy of DDRi. Induction of senescence and necrosis varied individually among the cell lines due to molecular heterogeneity and the involvement of DNA damage response pathways in senescence induction.
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Affiliation(s)
| | | | | | | | - Luitpold Distel
- Correspondence: ; Tel.: +49-9131-853-2312; Fax: +49-9131-853-9335
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16
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Zhao Y, Chen S. Targeting DNA Double-Strand Break (DSB) Repair to Counteract Tumor Radio-resistance. Curr Drug Targets 2020; 20:891-902. [PMID: 30806313 DOI: 10.2174/1389450120666190222181857] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 01/23/2019] [Accepted: 02/13/2019] [Indexed: 02/07/2023]
Abstract
During the last decade, advances of radiotherapy (RT) have been made in the clinical practice of cancer treatment. RT exerts its anticancer effect mainly via leading to the DNA Double-Strand Break (DSB), which is one of the most toxic DNA damages. Non-Homologous End Joining (NHEJ) and Homologous Recombination (HR) are two major DSB repair pathways in human cells. It is known that dysregulations of DSB repair elicit a predisposition to cancer and probably result in resistance to cancer therapies including RT. Therefore, targeting the DSB repair presents an attractive strategy to counteract radio-resistance. In this review, we describe the latest knowledge of the two DSB repair pathways, focusing on several key proteins contributing to the repair, such as DNA-PKcs, RAD51, MRN and PARP1. Most importantly, we discuss the possibility of overcoming radiation resistance by targeting these proteins for therapeutic inhibition. Recent tests of DSB repair inhibitors in the laboratory and their translations into clinical studies are also addressed.
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Affiliation(s)
- Yucui Zhao
- Department of Oncology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, China
| | - Siyu Chen
- Department of Oncology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, China
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17
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Willoughby CE, Jiang Y, Thomas HD, Willmore E, Kyle S, Wittner A, Phillips N, Zhao Y, Tudhope SJ, Prendergast L, Junge G, Lourenco LM, Finlay MRV, Turner P, Munck JM, Griffin RJ, Rennison T, Pickles J, Cano C, Newell DR, Reeves HL, Ryan AJ, Wedge SR. Selective DNA-PKcs inhibition extends the therapeutic index of localized radiotherapy and chemotherapy. J Clin Invest 2020; 130:258-271. [PMID: 31581151 PMCID: PMC6934184 DOI: 10.1172/jci127483] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 09/25/2019] [Indexed: 11/23/2022] Open
Abstract
Potentiating radiotherapy and chemotherapy by inhibiting DNA damage repair is proposed as a therapeutic strategy to improve outcomes for patients with solid tumors. However, this approach risks enhancing normal tissue toxicity as much as tumor toxicity, thereby limiting its translational impact. Using NU5455, a newly identified highly selective oral inhibitor of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) activity, we found that it was indeed possible to preferentially augment the effect of targeted radiotherapy on human orthotopic lung tumors without influencing acute DNA damage or a late radiation-induced toxicity (fibrosis) to normal mouse lung. Furthermore, while NU5455 administration increased both the efficacy and the toxicity of a parenterally administered topoisomerase inhibitor, it enhanced the activity of doxorubicin released locally in liver tumor xenografts without inducing any adverse effect. This strategy is particularly relevant to hepatocellular cancer, which is treated clinically with localized drug-eluting beads and for which DNA-PKcs activity is reported to confer resistance to treatment. We conclude that transient pharmacological inhibition of DNA-PKcs activity is effective and tolerable when combined with localized DNA-damaging therapies and thus has promising clinical potential.
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Affiliation(s)
- Catherine E. Willoughby
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Yanyan Jiang
- Cancer Research UK and UK Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Huw D. Thomas
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Elaine Willmore
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Suzanne Kyle
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Anita Wittner
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Nicole Phillips
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Yan Zhao
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Susan J. Tudhope
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Lisa Prendergast
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Gesa Junge
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Luiza Madia Lourenco
- Cancer Research UK and UK Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - M. Raymond V. Finlay
- Medicinal Chemistry, Oncology, IMED Biotech Unit, AstraZeneca, Cambridge, United Kingdom
| | - Paul Turner
- Medicinal Chemistry, Oncology, IMED Biotech Unit, AstraZeneca, Cambridge, United Kingdom
| | | | - Roger J. Griffin
- Cancer Research UK Newcastle Drug Discovery Unit, Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Tommy Rennison
- Cancer Research UK Newcastle Drug Discovery Unit, Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - James Pickles
- Cancer Research UK Newcastle Drug Discovery Unit, Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Celine Cano
- Cancer Research UK Newcastle Drug Discovery Unit, Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - David R. Newell
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Helen L. Reeves
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
- Hepatopancreatobiliary Multidisciplinary Team, Freeman Hospital, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Anderson J. Ryan
- Cancer Research UK and UK Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Stephen R. Wedge
- Cancer Research UK Newcastle Drug Discovery Unit, Translational and Clinical Research Institute, Newcastle University Centre for Cancer, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
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18
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Kopa P, Macieja A, Gulbas I, Pastwa E, Poplawski T. Inhibition of DNA-PK potentiates the synergistic effect of NK314 and etoposide combination on human glioblastoma cells. Mol Biol Rep 2019; 47:67-76. [PMID: 31583565 DOI: 10.1007/s11033-019-05105-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/25/2019] [Indexed: 12/20/2022]
Abstract
Etoposide (VP-16) is the topoisomerase 2 (Top2) inhibitor used for treating of glioma patients however at high dose with serious side effects. It induces DNA double-strand breaks (DSBs). These DNA lesions are repaired by non-homologous DNA end joining (NHEJ) mediated by DNA-dependent protein kinase (DNA-PK). One possible approach to decrease the toxicity of etoposide is to reduce the dose while maintaining the anticancer potential. It could be achieved through combined therapy with other anticancer drugs. We have assumed that this objective can be obtained by (1) a parallel topo2 α inhibition and (2) sensitization of cancer cells to DSBs. In this work we investigated the effect of two Top2 inhibitors NK314 and VP-16 in glioma cell lines (MO59 K and MO59 J) sensitized by DNA-PK inhibitor, NU7441. Cytotoxic effect of VP-16, NK314 alone and in combination on human glioblastoma cell lines, was assessed by a colorimetric assay. Genotoxic effect of anticancer drugs in combination with NU7441 was assessed by comet assay. Cell cycle distribution and apoptosis were analysed by flow cytometry. Compared with VP-16 or NK314 alone, the combined treatment significantly inhibited cell proliferation. Combination treatment was associated with a strong accumulation of DSBs, modulated cell cycle phases distribution and apoptotic cell death. NU7441 potentiated these effects and additionally postponed DNA repair. Our findings suggest that NK314 could overcome resistance of MO59 cells to VP-16 and NU7441 could serve as sensitizer to VP-16/NK314 combined treatment. The combined tripartite approach of chemotherapy could reduce the overall toxicity associated with each individual therapy, while concomitantly enhancing the anticancer effect to treat human glioma cells. Thus, the use of a tripartite combinatorial approach could be promising and more efficacious than mono therapy or dual therapy to treat and increase the survival of the glioblastoma patients.
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Affiliation(s)
- Paulina Kopa
- Department of Immunopathology, Division of Allergology, Immunology and Immunopathology, Faculty of Biomedical Sciences and Postgraduate Training, Medical University of Lodz, Lodz, Poland
| | - Anna Macieja
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Izabela Gulbas
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Elzbieta Pastwa
- Functional Genomics & Proteomics Unit, ITSI-Biosciences, Johnstown, PA, USA
| | - Tomasz Poplawski
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland.
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19
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Mohiuddin IS, Kang MH. DNA-PK as an Emerging Therapeutic Target in Cancer. Front Oncol 2019; 9:635. [PMID: 31380275 PMCID: PMC6650781 DOI: 10.3389/fonc.2019.00635] [Citation(s) in RCA: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 06/27/2019] [Indexed: 12/21/2022] Open
Abstract
The DNA-dependent protein kinase (DNA-PK) plays an instrumental role in the overall survival and proliferation of cells. As a member of the phosphatidylinositol 3-kinase-related kinase (PIKK) family, DNA-PK is best known as a mediator of the cellular response to DNA damage. In this context, DNA-PK has emerged as an intriguing therapeutic target in the treatment of a variety of cancers, especially when used in conjunction with genotoxic chemotherapy or ionizing radiation. Beyond the DNA damage response, DNA-PK activity is necessary for multiple cellular functions, including the regulation of transcription, progression of the cell cycle, and in the maintenance of telomeres. Here, we review what is currently known about DNA-PK regarding its structure and established roles in DNA repair. We also discuss its lesser-known functions, the pharmacotherapies inhibiting its function in DNA repair, and its potential as a therapeutic target in a broader context.
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Affiliation(s)
- Ismail S Mohiuddin
- Cancer Center, Department of Pediatrics, Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - Min H Kang
- Cancer Center, Department of Pediatrics, Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, United States
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20
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Teneng I, Picchi MA, Leng S, Dagucon CP, Ramalingam S, Tellez CS, Belinsky SA. DNA-PKc deficiency drives pre-malignant transformation by reducing DNA repair capacity in concert with reprogramming the epigenome in human bronchial epithelial cells. DNA Repair (Amst) 2019; 79:1-9. [PMID: 31055244 PMCID: PMC6551272 DOI: 10.1016/j.dnarep.2019.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/11/2019] [Accepted: 04/13/2019] [Indexed: 12/14/2022]
Abstract
The expression of DNA-dependent protein kinase catalytic subunit (DNA-PKc) is highly variable in smokers and reduced enzyme activity has been associated with risk for lung cancer. An in vitro model of lung pre-malignancy was used to evaluate the role of double-strand break DNA repair capacity in transformation of hTERT/CDK4 immortalized human bronchial epithelial cells (HBECs) and reprograming of the epigenome. Here we show that knockdown of DNA-PKc to levels simulating haploinsufficiency dramatically reduced DNA repair capacity following challenge with bleomycin and significantly increased transformation efficiency of HBEC lines exposed weekly for 12 weeks to this radiomimetic. Transformed HBEC lines with wild type or knockdown of DNA-PKc showed altered expression of more than 1,000 genes linked to major cell regulatory pathways involved in lung cancer. While lung cancer driver mutations were not detected in transformed clones, more than 300 genes that showed reduced expression associated with promoter methylation in transformed clones or predictive for methylation in malignant tumors were identified. These studies support reduced DNA repair capacity as a key factor in the initiation and clonal expansion of pre-neoplastic cells and double-strand break DNA damage as causal for epigenetic mediated silencing of many lung cancer-associated genes. The fact that DNA damage, repair, and epigenetic silencing of genes are causal for many other cancers that include colon and prostate extends the generalizability and impact of these findings.
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Affiliation(s)
- Ivo Teneng
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, NM, USA
| | - Maria A Picchi
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, NM, USA
| | - Shuguang Leng
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, NM, USA
| | | | - Suresh Ramalingam
- Department of Hematology and Oncology, Emory University School of Medicine, Winship Cancer Institute, Atlanta, GA, USA
| | - Carmen S Tellez
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, NM, USA
| | - Steven A Belinsky
- Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, NM, USA.
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21
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Choi C, Son A, Lee GH, Shin SW, Park S, Ahn SH, Chung Y, Yu JI, Park HC. Targeting DNA-dependent protein kinase sensitizes hepatocellular carcinoma cells to proton beam irradiation through apoptosis induction. PLoS One 2019; 14:e0218049. [PMID: 31194786 PMCID: PMC6563991 DOI: 10.1371/journal.pone.0218049] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/24/2019] [Indexed: 12/12/2022] Open
Abstract
Recent studies have highlighted the implications of genetic variations in the relative biological effectiveness (RBE) of proton beam irradiation over conventional X-ray irradiation. Proton beam radiotherapy is a reasonable radiotherapy option for hepatocellular carcinoma (HCC), but the impact of genetic difference on the HCC RBE remains unknown. Here, we determined proton RBE in human HCC cells by exposing them to various doses of either 6-MV X-rays or 230-MeV proton beams. Clonogenic survival assay revealed variable radiosensitivity of human HCC cell lines with survival fraction at 2 Gy ranging from 0.38 to 0.83 and variable proton RBEs with 37% survival fraction ranging from 1.00 to 1.48. HCC cells appeared more sensitive to proton irradiation than X-rays, with more persistent activation of DNA damage repair proteins over time. Depletion of a DNA damage repair gene, DNA-PKcs, by siRNA dramatically increased the sensitivity of HCC cells to proton beams with a decrease in colony survival and an increase in apoptosis. Our findings suggest that there are large variations in proton RBE in HCC cells despite the use of a constant RBE of 1.1 in the clinic and targeting DNA-PKcs in combination with proton beam therapy may be a promising regimen for treating HCC.
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Affiliation(s)
- Changhoon Choi
- Department of Radiation Oncology, Samsung Medical Center, Seoul, South Korea
| | - Arang Son
- Department of Radiation Oncology, Samsung Medical Center, Seoul, South Korea
| | - Ga-Haeng Lee
- Department of Radiation Oncology, Samsung Medical Center, Seoul, South Korea
| | - Sung-Won Shin
- Department of Radiation Oncology, Samsung Medical Center, Seoul, South Korea
- Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Sohee Park
- Department of Radiation Oncology, Samsung Medical Center, Seoul, South Korea
| | - Sang Hee Ahn
- Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Yoonsun Chung
- Department of Nuclear Engineering, Hanyang University, Seoul, South Korea
| | - Jeong Il Yu
- Department of Radiation Oncology, Samsung Medical Center, Seoul, South Korea
| | - Hee Chul Park
- Department of Radiation Oncology, Samsung Medical Center, Seoul, South Korea
- Sungkyunkwan University School of Medicine, Seoul, South Korea
- * E-mail:
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22
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Matsuno Y, Hyodo M, Fujimori H, Shimizu A, Yoshioka KI. Sensitization of Cancer Cells to Radiation and Topoisomerase I Inhibitor Camptothecin Using Inhibitors of PARP and Other Signaling Molecules. Cancers (Basel) 2018; 10:cancers10100364. [PMID: 30274183 PMCID: PMC6210148 DOI: 10.3390/cancers10100364] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 09/24/2018] [Accepted: 09/26/2018] [Indexed: 12/13/2022] Open
Abstract
Radiation and certain anticancer drugs damage DNA, resulting in apoptosis induction in cancer cells. Currently, the major limitations on the efficacy of such therapies are development of resistance and adverse side effects. Sensitization is an important strategy for increasing therapeutic efficacy while minimizing adverse effects. In this manuscript, we review possible sensitization strategies for radiation and anticancer drugs that cause DNA damage, focusing especially on modulation of damage repair pathways and the associated reactions.
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Affiliation(s)
- Yusuke Matsuno
- Division of Carcinogenesis and Cancer Prevention, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
- Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan.
| | - Mai Hyodo
- Division of Carcinogenesis and Cancer Prevention, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
- Biological Science and Technology, Tokyo University of Science, 6-1-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
| | - Haruka Fujimori
- Division of Carcinogenesis and Cancer Prevention, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
- Biological Science and Technology, Tokyo University of Science, 6-1-1 Niijuku, Katsushika-ku, Tokyo 125-8585, Japan.
| | - Atsuhiro Shimizu
- Division of Carcinogenesis and Cancer Prevention, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
| | - Ken-Ichi Yoshioka
- Division of Carcinogenesis and Cancer Prevention, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
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