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Park J, Lee HJ, Han YK, Kang K, Yi JM. Identification of DNA methylation biomarkers for evaluating cardiovascular disease risk from epigenome profiles altered by low-dose ionizing radiation. Clin Epigenetics 2024; 16:19. [PMID: 38303056 PMCID: PMC10835887 DOI: 10.1186/s13148-024-01630-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 01/16/2024] [Indexed: 02/03/2024] Open
Abstract
BACKGROUND Environmental exposure, medical diagnostic and therapeutic applications, and industrial utilization of radionuclides have prompted a growing focus on the risks associated with low-dose radiation (< 100 mGy). Current evidence suggests that such radiation can induce epigenetic changes. Nevertheless, whether exposure to low-dose radiation can disrupt endothelial cell function at the molecular level is unclear. Because endothelial cells play crucial roles in cardiovascular health and disease, we aimed to investigate whether low-dose radiation could lead to differential DNA methylation patterns at the genomic level in endothelial cell (EC) lines. METHODS We screened for changes in DNA methylation patterns in primary human aortic (HAECs) and coronary artery endothelial cells following exposure to low-dose ionizing radiation. Using a subset of genes altered via DNA methylation by low-dose irradiation, we performed gene ontology (GO) analysis to predict the possible biological network mediating the effect of low-dose radiation. In addition, we performed comprehensive validation using methylation and gene expression analyses, and ChIP assay to identify useful biomarkers among candidate genes for use in detecting low-dose radiation exposure in human primary normal ECs. RESULTS Low-dose radiation is sufficient to induce global DNA methylation alterations in normal EC lines. GO analysis demonstrated that these hyper- or hypo-methylated genes were linked to diverse biological pathways. Our findings indicated a robust correlation between promoter hypermethylation and transcriptional downregulation of four genes (PGRMC1, UNC119B, RERE, and FNDC3B) in response to low-dose ionizing radiation in HAECs. CONCLUSIONS Based on these findings, the identified genes can serve as potential DNA methylation biomarkers for the assessment of cardiovascular risk upon exposure to low-dose radiation.
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Affiliation(s)
- Jihye Park
- Department of Microbiology, Dankook University, Cheonan, 31116, South Korea
| | - Hae-June Lee
- Division of Radiation Biomedical Research, Korea Institute of Radiological and Medical Sciences, Seoul, 01812, South Korea
| | - Yu Kyeong Han
- Department of Microbiology and Immunology, College of Medicine, Inje University, Busan, 47392, South Korea
| | - Keunsoo Kang
- Department of Microbiology, Dankook University, Cheonan, 31116, South Korea
| | - Joo Mi Yi
- Department of Microbiology and Immunology, College of Medicine, Inje University, Busan, 47392, South Korea.
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2
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Sallam M, Mysara M, Benotmane MA, Crijns APG, Spoor D, Van Nieuwerburgh F, Deforce D, Baatout S, Guns PJ, Aerts A, Ramadan R. DNA Methylation Alterations in Fractionally Irradiated Rats and Breast Cancer Patients Receiving Radiotherapy. Int J Mol Sci 2022; 23:16214. [PMID: 36555856 PMCID: PMC9783664 DOI: 10.3390/ijms232416214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Radiation-Induced CardioVascular Disease (RICVD) is an important concern in thoracic radiotherapy with complex underlying pathophysiology. Recently, we proposed DNA methylation as a possible mechanism contributing to RICVD. The current study investigates DNA methylation in heart-irradiated rats and radiotherapy-treated breast cancer (BC) patients. Rats received fractionated whole heart X-irradiation (0, 0.92, 6.9 and 27.6 Gy total doses) and blood was collected after 1.5, 3, 7 and 12 months. Global and gene-specific methylation of the samples were evaluated; and gene expression of selected differentially methylated regions (DMRs) was validated in rat and BC patient blood. In rats receiving an absorbed dose of 27.6 Gy, DNA methylation alterations were detected up to 7 months with differential expression of cardiac-relevant DMRs. Of those, SLMAP showed increased expression at 1.5 months, which correlated with hypomethylation. Furthermore, E2F6 inversely correlated with a decreased global longitudinal strain. In BC patients, E2F6 and SLMAP exhibited differential expression directly and 6 months after radiotherapy, respectively. This study describes a systemic radiation fingerprint at the DNA methylation level, elucidating a possible association of DNA methylation to RICVD pathophysiology, to be validated in future mechanistic studies.
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Affiliation(s)
- Magy Sallam
- Radiobiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, 2400 Mol, Belgium
- Laboratory of Physiopharmacology, University of Antwerp, 2610 Wilrijk, Belgium
| | - Mohamed Mysara
- Radiobiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, 2400 Mol, Belgium
| | | | - Anne P. G. Crijns
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands
| | - Daan Spoor
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, The Netherlands
| | | | - Dieter Deforce
- Laboratory of Pharmaceutical Biotechnology, Ghent University, 9000 Ghent, Belgium
| | - Sarah Baatout
- Radiobiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, 2400 Mol, Belgium
- Department of Molecular Biotechnology, Ghent University, 9000 Ghent, Belgium
| | - Pieter-Jan Guns
- Laboratory of Physiopharmacology, University of Antwerp, 2610 Wilrijk, Belgium
| | - An Aerts
- Radiobiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, 2400 Mol, Belgium
| | - Raghda Ramadan
- Radiobiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre, SCK CEN, 2400 Mol, Belgium
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3
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López-Nieva P, González-Vasconcellos I, González-Sánchez L, Cobos-Fernández MA, Ruiz-García S, Sánchez Pérez R, Aroca Á, Fernández-Piqueras J, Santos J. Differential molecular response in mice and human thymocytes exposed to a combined-dose radiation regime. Sci Rep 2022; 12:3144. [PMID: 35210498 PMCID: PMC8873405 DOI: 10.1038/s41598-022-07166-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/11/2022] [Indexed: 11/17/2022] Open
Abstract
In the quest for more effective radiation treatment options that can improve both cell killing and healthy tissue recovery, combined radiation therapies are lately in the spotlight. The molecular response to a combined radiation regime where exposure to an initial low dose (priming dose) of ionizing radiation is administered prior to a subsequent higher radiation dose (challenging dose) after a given latency period have not been thoroughly explored. In this study we report on the differential response to either a combined radiation regime or a single challenging dose both in mouse in vivo and in human ex vivo thymocytes. A differential cell cycle response including an increase in the subG1 fraction on cells exposed to the combined regime was found. Together with this, a differential protein expression profiling in several pathways including cell cycle control (ATM, TP53, p21CDKN1A), damage response (γH2AX) and cell death pathways such as apoptosis (Cleaved Caspase-3, PARP1, PKCδ and H3T45ph) and ferroptosis (xCT/GPX4) was demonstrated. This study also shows the epigenetic regulation following a combined regime that alters the expression of chromatin modifiers such as DNMTs (DNMT1, DNMT2, DNMT3A, DNMT3B, DNMT3L) and glycosylases (MBD4 and TDG). Furthermore, a study of the underlying cellular status six hours after the priming dose alone showed evidence of retained modifications on the molecular and epigenetic pathways suggesting that the priming dose infers a “radiation awareness phenotype” to the thymocytes, a sensitization key to the differential response seen after the second hit with the challenging dose. These data suggest that combined-dose radiation regimes could be more efficient at making cells respond to radiation and it would be interesting to further investigate how can these schemes be of use to potential new radiation therapies.
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Affiliation(s)
- Pilar López-Nieva
- Genome Dynamics and Function Program, Genome Decoding Unit, Severo Ochoa Molecular Biology Center, Madrid, Spain. .,Department of Biology, Madrid Autonomous University, 28049, Madrid, Spain. .,Institute of Health Research, Jiménez Díaz Foundation, 28040, Madrid, Spain.
| | - Iria González-Vasconcellos
- Genome Dynamics and Function Program, Genome Decoding Unit, Severo Ochoa Molecular Biology Center, Madrid, Spain. .,Department of Biology, Madrid Autonomous University, 28049, Madrid, Spain.
| | - Laura González-Sánchez
- Genome Dynamics and Function Program, Genome Decoding Unit, Severo Ochoa Molecular Biology Center, Madrid, Spain.,Institute of Health Research, Jiménez Díaz Foundation, 28040, Madrid, Spain.,Consorcio de Investigación Biomédica de Enfermedades Raras (CIBERER), Madrid, Spain
| | - María A Cobos-Fernández
- Genome Dynamics and Function Program, Genome Decoding Unit, Severo Ochoa Molecular Biology Center, Madrid, Spain.,Department of Biology, Madrid Autonomous University, 28049, Madrid, Spain
| | - Sara Ruiz-García
- Genome Dynamics and Function Program, Genome Decoding Unit, Severo Ochoa Molecular Biology Center, Madrid, Spain.,Department of Biology, Madrid Autonomous University, 28049, Madrid, Spain
| | - Raúl Sánchez Pérez
- Department of Congenital Cardiac Surgery, Hospital Universitario La Paz, 28046, Madrid, Spain
| | - Ángel Aroca
- Department of Congenital Cardiac Surgery, Hospital Universitario La Paz, 28046, Madrid, Spain
| | - José Fernández-Piqueras
- Genome Dynamics and Function Program, Genome Decoding Unit, Severo Ochoa Molecular Biology Center, Madrid, Spain.,Department of Biology, Madrid Autonomous University, 28049, Madrid, Spain.,Institute of Health Research, Jiménez Díaz Foundation, 28040, Madrid, Spain
| | - Javier Santos
- Genome Dynamics and Function Program, Genome Decoding Unit, Severo Ochoa Molecular Biology Center, Madrid, Spain.,Department of Biology, Madrid Autonomous University, 28049, Madrid, Spain.,Institute of Health Research, Jiménez Díaz Foundation, 28040, Madrid, Spain
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4
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Sallam M, Benotmane MA, Baatout S, Guns PJ, Aerts A. Radiation-induced cardiovascular disease: an overlooked role for DNA methylation? Epigenetics 2022; 17:59-80. [PMID: 33522387 PMCID: PMC8812767 DOI: 10.1080/15592294.2021.1873628] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 11/27/2020] [Accepted: 01/04/2021] [Indexed: 11/25/2022] Open
Abstract
Radiotherapy in cancer treatment involves the use of ionizing radiation for cancer cell killing. Although radiotherapy has shown significant improvements on cancer recurrence and mortality, several radiation-induced adverse effects have been documented. Of these adverse effects, radiation-induced cardiovascular disease (CVD) is particularly prominent among patients receiving mediastinal radiotherapy, such as breast cancer and Hodgkin's lymphoma patients. A number of mechanisms of radiation-induced CVD pathogenesis have been proposed such as endothelial inflammatory activation, premature endothelial senescence, increased ROS and mitochondrial dysfunction. However, current research seems to point to a so-far unexamined and potentially novel involvement of epigenetics in radiation-induced CVD pathogenesis. Firstly, epigenetic mechanisms have been implicated in CVD pathophysiology. In addition, several studies have shown that ionizing radiation can cause epigenetic modifications, especially DNA methylation alterations. As a result, this review aims to provide a summary of the current literature linking DNA methylation to radiation-induced CVD and thereby explore DNA methylation as a possible contributor to radiation-induced CVD pathogenesis.
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Affiliation(s)
- Magy Sallam
- Radiobiology Unit, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
- Laboratory of Physiopharmacology, University of Antwerp, Wilrijk, Belgium
| | - Mohammed Abderrafi Benotmane
- Radiobiology Unit, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
| | - Sarah Baatout
- Radiobiology Unit, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
- Department of Molecular Biotechnology, Ghent University, Ghent, Belgium
| | - Pieter-Jan Guns
- Laboratory of Physiopharmacology, University of Antwerp, Wilrijk, Belgium
| | - An Aerts
- Radiobiology Unit, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK CEN), Mol, Belgium
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Becker BV, Kaatsch HL, Nestler K, Jakobi J, Schäfer B, Hantke T, Brockmann MA, Waldeck S, Port M, Ullmann R. Impact of medical imaging on the epigenome - low-dose exposure in the course of computed tomography does not induce detectable changes of DNA-methylation profiles in peripheral blood cells. Int J Radiat Biol 2021; 98:980-985. [PMID: 34779695 DOI: 10.1080/09553002.2021.2004329] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Computed tomography (CT) is a main contributor to artificial low-dose exposure. Understanding the biological effects induced by CT exposure and their dependency on the characteristics of photon spectra is essential for knowledge-driven risk assessment. In a previous gene expression study, we have identified upregulation of AEN, BAX, DDB2, EDA2R and FDXR after ex vivo exposure with single-energy CT and dual-energy CT (DECT). In this study, we focused on CT-induced changes of DNA methylation. This epigenetic modification of DNA is a central regulator of gene expression and instrumental in preserving genome integrity. Previous studies reported focal hypermethylation and global hypomethylation after exposure with doses above 100 mSv, however, the effect of low dose exposure on DNA methylation is hardly explored. MATERIALS AND METHODS DNA was isolated from peripheral blood of three healthy individuals 6 h after ex vivo exposition to single-energy (80 kV and 150 kV) and DECT (80 kV/Sn150 kV) with a calculated effective dose of 7.0 ± 0.08 mSv. The experimental setting was identical to the one used in our previous gene expression study enabling a direct comparison of gene expression results with changes of DNA methylation identified in this study. DNA methylation was analyzed by high-throughput sequencing of bisulfite-treated DNA targeted methylation sequencing. RESULTS Unsupervised hierarchical clustering based on DNA methylation profiles of all samples created three distinct clusters. Formation of these three clusters was solely determined by the origin of samples, indicating the absence of prominent irradiation-associated changes of DNA methylation. In line with this observation, inter-individual comparison of non-irradiated samples revealed 1163, 1224 and 4550 significant differentially methylated regions (DMRs), respectively, whereas the pairwise comparison of irradiated and non-irradiated samples failed to identify irradiation-induced DMRs in any of the three probands. This even applied to the genomic regions harboring AEN, BAX, DDB2, EDA2R and FDXR, the five genes known to be upregulated by CT exposure. CONCLUSIONS CT exposure with various photon spectra did not result in detectable changes of DNA methylation. However, minor effects in a subpopulation of irradiated cells cannot be ruled out. Thus, future studies with extended observation intervals are needed to investigate DNA methylation changes that are induced by indirect effects at later points of time or become detectable by clonal expansion of affected cells. Moreover, our data suggest that DNA methylation analysis is less sensitive in detecting immediate effects of low-dose irradiation when compared to gene expression analysis.
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Affiliation(s)
| | | | - Kai Nestler
- Department of Radiology and Neuroradiology, Bundeswehr Central Hospital, Koblenz, Germany
| | - Julia Jakobi
- Bundeswehr Institute of Radiobiology Affiliated to Ulm University, Munich, Germany
| | - Barbara Schäfer
- Bundeswehr Institute of Radiobiology Affiliated to Ulm University, Munich, Germany
| | - Thomas Hantke
- Bundeswehr Institute of Radiobiology Affiliated to Ulm University, Munich, Germany
| | - Marc A Brockmann
- Department of Neuroradiology, University Medical Center Mainz, Mainz, Germany
| | - Stephan Waldeck
- Department of Radiology and Neuroradiology, Bundeswehr Central Hospital, Koblenz, Germany
| | - Matthias Port
- Bundeswehr Institute of Radiobiology Affiliated to Ulm University, Munich, Germany
| | - Reinhard Ullmann
- Bundeswehr Institute of Radiobiology Affiliated to Ulm University, Munich, Germany
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6
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Averbeck D, Rodriguez-Lafrasse C. Role of Mitochondria in Radiation Responses: Epigenetic, Metabolic, and Signaling Impacts. Int J Mol Sci 2021; 22:ijms222011047. [PMID: 34681703 PMCID: PMC8541263 DOI: 10.3390/ijms222011047] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/24/2021] [Accepted: 10/08/2021] [Indexed: 12/15/2022] Open
Abstract
Until recently, radiation effects have been considered to be mainly due to nuclear DNA damage and their management by repair mechanisms. However, molecular biology studies reveal that the outcomes of exposures to ionizing radiation (IR) highly depend on activation and regulation through other molecular components of organelles that determine cell survival and proliferation capacities. As typical epigenetic-regulated organelles and central power stations of cells, mitochondria play an important pivotal role in those responses. They direct cellular metabolism, energy supply and homeostasis as well as radiation-induced signaling, cell death, and immunological responses. This review is focused on how energy, dose and quality of IR affect mitochondria-dependent epigenetic and functional control at the cellular and tissue level. Low-dose radiation effects on mitochondria appear to be associated with epigenetic and non-targeted effects involved in genomic instability and adaptive responses, whereas high-dose radiation effects (>1 Gy) concern therapeutic effects of radiation and long-term outcomes involving mitochondria-mediated innate and adaptive immune responses. Both effects depend on radiation quality. For example, the increased efficacy of high linear energy transfer particle radiotherapy, e.g., C-ion radiotherapy, relies on the reduction of anastasis, enhanced mitochondria-mediated apoptosis and immunogenic (antitumor) responses.
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Affiliation(s)
- Dietrich Averbeck
- Laboratory of Cellular and Molecular Radiobiology, PRISME, UMR CNRS 5822/IN2P3, IP2I, Lyon-Sud Medical School, University Lyon 1, 69921 Oullins, France;
- Correspondence:
| | - Claire Rodriguez-Lafrasse
- Laboratory of Cellular and Molecular Radiobiology, PRISME, UMR CNRS 5822/IN2P3, IP2I, Lyon-Sud Medical School, University Lyon 1, 69921 Oullins, France;
- Department of Biochemistry and Molecular Biology, Lyon-Sud Hospital, Hospices Civils de Lyon, 69310 Pierre-Bénite, France
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7
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Hu C, Liu X, Zeng Y, Liu J, Wu F. DNA methyltransferase inhibitors combination therapy for the treatment of solid tumor: mechanism and clinical application. Clin Epigenetics 2021; 13:166. [PMID: 34452630 PMCID: PMC8394595 DOI: 10.1186/s13148-021-01154-x] [Citation(s) in RCA: 82] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 08/16/2021] [Indexed: 12/15/2022] Open
Abstract
DNA methylation, an epigenetic modification, regulates gene transcription and maintains genome stability. DNA methyltransferase (DNMT) inhibitors can activate silenced genes at low doses and cause cytotoxicity at high doses. The ability of DNMT inhibitors to reverse epimutations is the basis of their use in novel strategies for cancer therapy. In this review, we examined the literature on DNA methyltransferase inhibitors. We summarized the mechanisms underlying combination therapy using DNMT inhibitors and clinical trials based on combining hypomethylation agents with other chemotherapeutic drugs. We also discussed the efficacy of such compounds as antitumor agents, the need to optimize treatment schedules and the regimens for maximal biologic effectiveness. Notably, the combination of DNMT inhibitors and chemotherapy and/or immune checkpoint inhibitors may provide helpful insights into the development of efficient therapeutic approaches.
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Affiliation(s)
- Chunhong Hu
- Department of Oncology, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China.,Hunan Cancer Mega-Data Intelligent Application and Engineering Research Centre, Changsha, 410011, Hunan, China
| | - Xiaohan Liu
- Department of Oncology, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China
| | - Yue Zeng
- Department of Oncology, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China
| | - Junqi Liu
- Department of Oncology, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China
| | - Fang Wu
- Department of Oncology, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China. .,Hunan Key Laboratory of Tumor Models and Individualized Medicine, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China. .,Hunan Key Laboratory of Early Diagnosis and Precision Therapy in Lung Cancer, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China. .,Hunan Cancer Mega-Data Intelligent Application and Engineering Research Centre, Changsha, 410011, Hunan, China.
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8
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MicroRNA-9 enhanced radiosensitivity and its mechanism of DNA methylation in non-small cell lung cancer. Gene 2019; 710:178-185. [PMID: 31158449 DOI: 10.1016/j.gene.2019.05.050] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/17/2019] [Accepted: 05/25/2019] [Indexed: 12/30/2022]
Abstract
In order to improve the therapeutic effect of non-small cell lung cancer (NSCLC), it is critical to combine radiation and gene therapy. Our study found that the activation of microRNA-9 (miR-9) conferred ionizing radiation (IR) sensitivity in cancer cells. Furthermore, increased microRNA-9 promoter methylation level was observed after IR. Our study combined the IR and microRNA-9 overexpression treatment which leads to a significant enhancement in the therapeutic efficiency in lung cancer both in vitro and in vivo. Therefore, it is plausible that microRNA-9 can be used as a novel therapeutic strategy of NSCLC. MTT assay was performed to detect the effect of microRNA-9 on the survival and growth of NSCLC cells. Flow cytometry results showed that microRNA-9 enhanced the apoptosis of NSCLC cells. Wound healing assay found that microRNA-9 can inhibit the migration of NSCLC cells and enhance the effect of radiation on the migration of NSCLC cells. In addition, bisulfate sequencing PCR was performed to analyze the methylation status of the microRNA-9 promoter. In order to determine the effect of microRNA-9 and its promoter methylation status on proliferation and radio-sensitivity in vivo, a subcutaneous tumor formation assay in nude mice was performed. Results have shown that microRNA-9 overexpression increased the radiosensitivity of A549 cells by inhibiting cell activity and migration, and by increasing apoptosis. In addition, the promoter methylation status of the microRNA-9 gene increased in response to ionizing radiation. Our study demonstrated that microRNA-9 enhanced radiosensitivity in NSCLC and this effect is highly regulated by its promoter methylation status. These results will help to clarify regulatory mechanisms of radiation resistance thus stimulate new methods for improving radiotherapy for NSCLC.
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Cho YH, Jang Y, Woo HD, Kim YJ, Kim SY, Christensen S, Cole E, Choi SY, Chung HW. LINE-1 hypomethylation is associated with radiation-induced genomic instability in industrial radiographers. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:174-184. [PMID: 30488609 PMCID: PMC6363886 DOI: 10.1002/em.22237] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/15/2018] [Accepted: 08/10/2018] [Indexed: 06/09/2023]
Abstract
Global DNA hypomethylation is proposed as a potential biomarker for cancer risk associated with genomic instability, which is an important factor in radiation-induced cancer. However, the associations among radiation exposure, changes in DNA methylation, and carcinogenesis are unclear. The aims of this study were (1) to examine whether low-level occupational radiation exposure induces genomic DNA hypomethylation; and (2) to determine the relationships between radiation exposure, genomic DNA hypomethylation and radiation-induced genomic instability (RIGI) in industrial radiographers. Genomic DNA methylation levels were measured in blood DNA from 40 radiographers and 28 controls using the LINE-1 pyrosequencing assay and the luminometric methylation assay. Further, the micronucleus-centromere assay was performed to measure aneuploidy of chromosomes 1 and 4 as a marker of delayed RIGI. Genomic DNA methylation levels were significantly lower in radiographers than those in controls. LINE-1 hypomethylation was not significantly correlated with recent 1-year, recent 3-year, or total cumulative radiation doses in radiographers; however, LINE-1 hypomethylation significantly correlated with the cumulative radiation dose without recent 3-year exposure data (D3dose, r = -0.39, P < 0.05). In addition, LINE-1 hypomethylation was a significant contributor to aneuploidy frequency by D3dose (F (2, 34) = 13.85, P < 0.001), in which a total of 45% of the variance in aneuploidy frequency was explained. Our results provide suggestive evidence regarding the delayed effects of low-dose occupational radiation exposure in radiographers and its association with LINE-1 hypomethylation; however, additional studies using more subjects are needed to fully understand the relationship between genomic DNA hypomethylation and RIGI. Environ. Mol. Mutagen. 60: 174-184, 2019. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Yoon Hee Cho
- Departments of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, USA
| | - Yoonhee Jang
- Departments of Psychology, The University of Montana, Missoula, MT, USA
| | - Hae Dong Woo
- Molecular Epidemiology Branch, Division of Cancer Epidemiology and Prevention, Research Institute, National Cancer Center, Goyang-si, Gyeonggi-do, Korea
| | - Yang Jee Kim
- Da Vinci College of General Education, Chung-Ang University, Seoul, Korea
| | - Su Young Kim
- Departments of Preventive Medicine, School of Medicine, Jeju National University, Jeju-si, Jeju-do, Korea
| | - Sonja Christensen
- Departments of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, USA
| | - Elizabeth Cole
- Departments of Biomedical and Pharmaceutical Sciences, The University of Montana, Missoula, MT, USA
| | - Soo Yong Choi
- Laboratory of Radiation Effect, Korea Institute of Radiological and Medical Science, Seoul Korea
| | - Hai Won Chung
- School of Public Health, Seoul National University, Seoul, Korea
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10
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Sensitization of prostate cancer to radiation therapy: Molecules and pathways to target. Radiother Oncol 2018; 128:283-300. [PMID: 29929859 DOI: 10.1016/j.radonc.2018.05.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 05/01/2018] [Accepted: 05/17/2018] [Indexed: 12/11/2022]
Abstract
Radiation therapy is used to treat cancer by radiation-induced DNA damage. Despite the best efforts to eliminate cancer, some cancer cells survive irradiation, resulting in cancer progression or recurrence. Alteration in DNA damage repair pathways is common in cancers, resulting in modulation of their response to radiation. This article focuses on the recent findings about molecules and pathways that potentially can be targeted to sensitize prostate cancer cells to ionizing radiation, thereby achieving an improved therapeutic outcome.
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11
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Christmann M, Kaina B. Epigenetic regulation of DNA repair genes and implications for tumor therapy. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2017; 780:15-28. [PMID: 31395346 DOI: 10.1016/j.mrrev.2017.10.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 10/05/2017] [Accepted: 10/06/2017] [Indexed: 12/31/2022]
Abstract
DNA repair represents the first barrier against genotoxic stress causing metabolic changes, inflammation and cancer. Besides its role in preventing cancer, DNA repair needs also to be considered during cancer treatment with radiation and DNA damaging drugs as it impacts therapy outcome. The DNA repair capacity is mainly governed by the expression level of repair genes. Alterations in the expression of repair genes can occur due to mutations in their coding or promoter region, changes in the expression of transcription factors activating or repressing these genes, and/or epigenetic factors changing histone modifications and CpG promoter methylation or demethylation levels. In this review we provide an overview on the epigenetic regulation of DNA repair genes. We summarize the mechanisms underlying CpG methylation and demethylation, with de novo methyltransferases and DNA repair involved in gain and loss of CpG methylation, respectively. We discuss the role of components of the DNA damage response, p53, PARP-1 and GADD45a on the regulation of the DNA (cytosine-5)-methyltransferase DNMT1, the key enzyme responsible for gene silencing. We stress the relevance of epigenetic silencing of DNA repair genes for tumor formation and tumor therapy. A paradigmatic example is provided by the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT), which is silenced in up to 40% of various cancers through CpG promoter methylation. The CpG methylation status of the MGMT promoter strongly correlates with clinical outcome and, therefore, is used as prognostic marker during glioblastoma therapy. Mismatch repair genes are also subject of epigenetic silencing, which was shown to correlate with colorectal cancer formation. For many other repair genes shown to be epigenetically regulated the clinical outcome is not yet clear. We also address the question of whether genotoxic stress itself can lead to epigenetic alterations of genes encoding proteins involved in the defense against genotoxic stress.
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Affiliation(s)
- Markus Christmann
- Department of Toxicology, University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany.
| | - Bernd Kaina
- Department of Toxicology, University of Mainz, Obere Zahlbacher Str. 67, D-55131 Mainz, Germany.
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12
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Alghamian Y, Abou Alchamat G, Murad H, Madania A. Effects of γ-radiation on cell growth, cell cycle and promoter methylation of 22 cell cycle genes in the 1321NI astrocytoma cell line. Adv Med Sci 2017; 62:330-337. [PMID: 28511071 DOI: 10.1016/j.advms.2017.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 03/02/2017] [Accepted: 03/09/2017] [Indexed: 12/11/2022]
Abstract
PURPOSE DNA damage caused by radiation initiates biological responses affecting cell fate. DNA methylation regulates gene expression and modulates DNA damage pathways. Alterations in the methylation profiles of cell cycle regulating genes may control cell response to radiation. In this study we investigated the effect of ionizing radiation on the methylation levels of 22 cell cycle regulating genes in correlation with gene expression in 1321NI astrocytoma cell line. METHODS 1321NI cells were irradiated with 2, 5 or 10Gy doses then analyzed after 24, 48 and 72h for cell viability using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliu bromide) assay. Flow cytometry were used to study the effect of 10Gy irradiation on cell cycle. EpiTect Methyl II PCR Array was used to identify differentially methylated genes in irradiated cells. Changes in gene expression was determined by qPCR. Azacytidine treatment was used to determine whether DNA methylation affectes gene expression. RESULTS Our results showed that irradiation decreased cell viability and caused cell cycle arrest at G2/M. Out of 22 genes tested, only CCNF and RAD9A showed some increase in DNA methylation (3.59% and 3.62%, respectively) after 10Gy irradiation, and this increase coincided with downregulation of both genes (by 4 and 2 fold, respectively). TREATMENT with azacytidine confirmed that expression of CCNF and RAD9A genes was regulated by methylation. CONCLUSIONS 1321NI cell line is highly radioresistant and that irradiation of these cells with a 10Gy dose increases DNA methylation of CCNF and RAD9A genes. This dose down-regulates these genes, favoring G2/M arrest.
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13
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Giorgi G, Pirazzini C, Bacalini MG, Giuliani C, Garagnani P, Capri M, Bersani F, Del Re B. Assessing the combined effect of extremely low-frequency magnetic field exposure and oxidative stress on LINE-1 promoter methylation in human neural cells. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2017; 56:193-200. [PMID: 28258386 DOI: 10.1007/s00411-017-0683-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 01/11/2017] [Indexed: 06/06/2023]
Abstract
Extremely low frequency magnetic fields (ELF-MF) have been classified as "possibly carcinogenic", but their genotoxic effects are still unclear. Recent findings indicate that epigenetic mechanisms contribute to the genome dysfunction and it is well known that they are affected by environmental factors. To our knowledge, to date the question of whether exposure to ELF-MF can influence epigenetic modifications has been poorly addressed. In this paper, we investigated whether exposure to ELF-MF alone and in combination with oxidative stress (OS) can affect DNA methylation, which is one of the most often studied epigenetic modification. To this end, we analyzed the DNA methylation levels of the 5'untranslated region (5'UTR) of long interspersed nuclear element-1s (LINE-1 or L1), which are commonly used to evaluate the global genome methylation level. Human neural cells (BE(2)C) were exposed for 24 and 48 h to extremely low frequency pulsed magnetic field (PMF; 50 Hz, 1 mT) in combination with OS. The methylation levels of CpGs located in L1 5'UTR region were measured by MassARRAY EpiTYPER. The results indicate that exposures to the single agents PMF and OS induced weak decreases and increases of DNA methylation levels at different CpGs. However, the combined exposure to PMF and OS lead to significant decrease of DNA methylation levels at different CpG sites. Most of the changes were transient, suggesting that cells can restore homeostatic DNA methylation patterns. The results are discussed and future research directions outlined.
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Affiliation(s)
- Gianfranco Giorgi
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, via Selmi 3, 40126, Bologna, Italy
| | - Chiara Pirazzini
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, via S. Giacomo 12, 40126, Bologna, Italy
| | - Maria Giulia Bacalini
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, via S. Giacomo 12, 40126, Bologna, Italy
| | - Cristina Giuliani
- Department of Biological, Geological and Environmental Sciences (BiGeA), Centre for Genome Biology, University of Bologna, via Selmi 3, 40126, Bologna, Italy
| | - Paolo Garagnani
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, via S. Giacomo 12, 40126, Bologna, Italy
- CIG-Interdepartmental Centre "L. Galvani" for Bioinformatics, Biophysics and Biocomplexity, Piazza di Porta San Donato 1, 40126, Bologna, Italy
| | - Miriam Capri
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, via S. Giacomo 12, 40126, Bologna, Italy
- CIG-Interdepartmental Centre "L. Galvani" for Bioinformatics, Biophysics and Biocomplexity, Piazza di Porta San Donato 1, 40126, Bologna, Italy
| | - Ferdinando Bersani
- DIFA Department of Physics and Astronomy, University of Bologna, via Berti Pichat 6/2, 40127, Bologna, Italy
| | - Brunella Del Re
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, via Selmi 3, 40126, Bologna, Italy.
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Genetic and epigenetic changes in host ABCB1 influences malaria susceptibility to Plasmodium falciparum. PLoS One 2017; 12:e0175702. [PMID: 28422980 PMCID: PMC5397027 DOI: 10.1371/journal.pone.0175702] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 03/30/2017] [Indexed: 01/20/2023] Open
Abstract
Multiple mechanisms such as genetic and epigenetic variations within a key gene may play a role in malarial susceptibility and response to anti-malarial drugs in the population. ABCB1 is one of the well-studied membrane transporter genes that code for the P-glycoprotein (an efflux protein) and whose effect on malaria disease predisposition and susceptibility to drugs remains to be understood. We studied the association of single nucleotide variations in human ABCB1 that influences its function in subjects with uncomplicated and complicated malaria caused by Plasmodium falciparum (Pf). Global DNA methylation and ABCB1 DNA promoter methylation levels were performed along with transcriptional response and protein expression in subjects with malaria and healthy controls. The rs2032582 locus was significantly associated with complicated and combined malaria groups when compared to controls (p < 0.05). Significant DNA methylation difference was noticed between case and control (p < 0.05). In addition, global DNA methylation levels of the host DNA were inversely proportional to parasitemia in individuals with Pf infection. Our study also revealed the correlation between ABCB1 DNA promoter methylation with rs1128503 and rs2032582 polymorphisms in malaria and was related to increased expression of ABCB1 protein levels in complicated malaria group (p < 0.05) when compared to uncomplicated malaria and control groups. The study provides evidence for multiple mechanisms that may regulate the role of host ABCB1 function to mediate aetiology of malaria susceptibility, prognosis and drug response. These may have clinical implications and therapeutic application for various malarial conditions.
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15
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Skrdlant L, Stark JM, Lin RJ. Myelodysplasia-associated mutations in serine/arginine-rich splicing factor SRSF2 lead to alternative splicing of CDC25C. BMC Mol Biol 2016; 17:18. [PMID: 27552991 PMCID: PMC4994158 DOI: 10.1186/s12867-016-0071-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 08/16/2016] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Serine-arginine rich splicing factor 2 (SRSF2) is a protein known for its role in RNA splicing and genome stability. It has been recently discovered that SRSF2, along with other splicing regulators, is frequently mutated in patients with myelodysplastic syndrome (MDS). The most common MDS mutations in SRSF2 occur at proline 95; the mutant proteins are shown to have different RNA binding preferences, which may contribute to splicing changes detected in mutant cells. However, the influence of these SRSF2 MDS-associated mutations on specific splicing events remains poorly understood. RESULTS A tetracycline-inducible TF-1 erythroleukemia cell line was transduced with retroviruses to create cell lines expressing HA-tagged wildtype SRSF2, SRSF2 with proline 95 point mutations found in MDS, or SRSF2 with a deletion of one of the four major domains of the protein. Effects of these mutants on apoptosis and specific alternative splicing events were evaluated. Cells were also treated with DNA damaging drugs for comparison. MDS-related P95 point mutants of SRSF2 were expressed and phosphorylated at similar levels as wildtype SRSF2. However, cells expressing mutant SRSF2 exhibited higher levels of apoptosis than cells expressing wildtype SRSF2. Regarding alternative splicing events, in nearly all examined cases, SRSF2 P95 mutants acted in a similar fashion as the wildtype SRSF2. However, cells expressing SRSF2 P95 mutants had a percent increase in the C5 spliced isoform of cell division cycle 25C (CDC25C). The same alternative splicing of CDC25C was detected by treating cells with DNA damaging drugs, such as cisplatin, camptothecin, and trichostatin A at appropriate dosage. However, unlike DNA damaging drugs, SRSF2 P95 mutants did not activate the Ataxia telangiectasia mutated (ATM) pathway. CONCLUSION SRSF2 P95 mutants lead to alternative splicing of CDC25C in a manner that is not dependent on the DNA damage response.
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Affiliation(s)
- Lindsey Skrdlant
- Department of Molecular and Cellular Biology, Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010 USA
| | - Jeremy M. Stark
- Department of Cancer Genetics and Epigenetics, Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010 USA
| | - Ren-Jang Lin
- Department of Molecular and Cellular Biology, Irell & Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010 USA
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16
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Kim B, Bae H, Lee H, Lee S, Park JC, Kim KR, Kim SJ. Proton Beams Inhibit Proliferation of Breast Cancer Cells by Altering DNA Methylation Status. J Cancer 2016; 7:344-52. [PMID: 26918048 PMCID: PMC4747889 DOI: 10.7150/jca.13396] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/15/2015] [Indexed: 12/04/2022] Open
Abstract
Proton beam therapy has been gaining popularity in the management of a wide spectrum of cancers. However, little is known about the effect of proton beams on epigenetic alterations. In this study, the effects of proton beams on DNA methylation were evaluated in the breast cell lines MCF-10A and MCF-7. Pyrosequencing analysis of the long interspersed element 1 (LINE1) gene indicated that a few specific CpG sites were induced to be hypermethylated by proton beam treatment from 64.5 to 76.5% and from 57.7 to 60.0% (p < 0.05) in MCF-10A and MCF-7, respectively. Genome-wide methylation analysis identified “Developmental Disorder, Hereditary Disorder, Metabolic Disease” as the top network in the MCF-7 cell line. The proliferation rate significantly decreased in proton beam-treated cells, as judged by colony formation and cell proliferation assay. Upon treatment with the proton beam, expression of selected genes (MDH2, STYXL1, CPE, FAM91A1, and GPR37) was significantly changed in accordance with the changes of methylation level. Taken together, the findings demonstrate that proton beam-induced physiological changes of cancer cells via methylation modification assists in establishing the epigenetic basis of proton beam therapy for cancer.
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Affiliation(s)
- Byungtak Kim
- 1. Department of Life Science, Dongguk University-Seoul, Goyang, Korea
| | - Hansol Bae
- 1. Department of Life Science, Dongguk University-Seoul, Goyang, Korea
| | - Hyunkyung Lee
- 1. Department of Life Science, Dongguk University-Seoul, Goyang, Korea
| | - Seungyeon Lee
- 1. Department of Life Science, Dongguk University-Seoul, Goyang, Korea
| | - Jeong Chan Park
- 2. Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju, Korea
| | - Kye Ryung Kim
- 2. Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju, Korea
| | - Sun Jung Kim
- 1. Department of Life Science, Dongguk University-Seoul, Goyang, Korea
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17
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Iordanskiy S, Van Duyne R, Sampey GC, Woodson CM, Fry K, Saifuddin M, Guo J, Wu Y, Romerio F, Kashanchi F. Therapeutic doses of irradiation activate viral transcription and induce apoptosis in HIV-1 infected cells. Virology 2015; 485:1-15. [PMID: 26184775 DOI: 10.1016/j.virol.2015.06.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 05/13/2015] [Accepted: 06/16/2015] [Indexed: 01/17/2023]
Abstract
The highly active antiretroviral therapy reduces HIV-1 RNA in plasma to undetectable levels. However, the virus continues to persist in the long-lived resting CD4(+) T cells, macrophages and astrocytes which form a viral reservoir in infected individuals. Reactivation of viral transcription is critical since the host immune response in combination with antiretroviral therapy may eradicate the virus. Using the chronically HIV-1 infected T lymphoblastoid and monocytic cell lines, primary quiescent CD4(+) T cells and humanized mice infected with dual-tropic HIV-1 89.6, we examined the effect of various X-ray irradiation (IR) doses (used for HIV-related lymphoma treatment and lower doses) on HIV-1 transcription and viability of infected cells. Treatment of both T cells and monocytes with IR, a well-defined stress signal, led to increase of HIV-1 transcription, as evidenced by the presence of RNA polymerase II and reduction of HDAC1 and methyl transferase SUV39H1 on the HIV-1 promoter. This correlated with the increased GFP signal and elevated level of intracellular HIV-1 RNA in the IR-treated quiescent CD4(+) T cells infected with GFP-encoding HIV-1. Exposition of latently HIV-1infected monocytes treated with PKC agonist bryostatin 1 to IR enhanced transcription activation effect of this latency-reversing agent. Increased HIV-1 replication after IR correlated with higher cell death: the level of phosphorylated Ser46 in p53, responsible for apoptosis induction, was markedly higher in the HIV-1 infected cells following IR treatment. Exposure of HIV-1 infected humanized mice with undetectable viral RNA level to IR resulted in a significant increase of HIV-1 RNA in plasma, lung and brain tissues. Collectively, these data point to the use of low to moderate dose of IR alone or in combination with HIV-1 transcription activators as a potential application for the "Shock and Kill" strategy for latently HIV-1 infected cells.
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Affiliation(s)
- Sergey Iordanskiy
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Rachel Van Duyne
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA; Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Gavin C Sampey
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Caitlin M Woodson
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Kelsi Fry
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Mohammed Saifuddin
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Jia Guo
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Yuntao Wu
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA
| | - Fabio Romerio
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Fatah Kashanchi
- School of Systems Biology, Laboratory of Molecular Virology, George Mason University, Manassas, VA 20110, USA.
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18
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Xue G, Ren Z, Chen Y, Zhu J, Du Y, Pan D, Li X, Hu B. A feedback regulation between miR-145 and DNA methyltransferase 3b in prostate cancer cell and their responses to irradiation. Cancer Lett 2015; 361:121-7. [PMID: 25749421 DOI: 10.1016/j.canlet.2015.02.046] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 02/24/2015] [Accepted: 02/26/2015] [Indexed: 02/02/2023]
Abstract
It is believed that epigenetic modification plays roles in cancer initiation and progression. Both microRNA and DNA methyltransferase are epigenetic regulation factors. It was found that miR-145 upregulates while DNMT3b downregulates in PC3 cells. Presence of any negative correlationship and their response to irradiation were investigated in the current study. We found that miR-145 downregulated DNMT3b expression by directly targeting the 3'-UTR of DNMT3b mRNA and knockdown of DNMT3b increased expression of miR-145 via CpG island promoter hypomethylation, suggesting that there is a crucial crosstalk between miR-145 and DNMT3b via a double-negative feedback loop. Responses of the miR-145 and DNMT3b to irradiation are a negative correlation. We also found that either overexpression of miR-145 or knockdown of DNMT3b sensitized prostate cancer cells to X-ray radiation. Our findings enrich the complex relationships between miRNA and DNMTs in carcinogenesis and irradiation stress. It also sheds light on the potential combination of ionizing radiation and epigenetic regulation in prostate cancer therapy.
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Affiliation(s)
- Gang Xue
- Department of Space Radiobiology, Key Laboratory of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhenxin Ren
- Department of Space Radiobiology, Key Laboratory of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Yaxiong Chen
- Department of Space Radiobiology, Key Laboratory of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Jiayun Zhu
- Department of Space Radiobiology, Key Laboratory of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Yarong Du
- Department of Space Radiobiology, Key Laboratory of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Dong Pan
- Department of Space Radiobiology, Key Laboratory of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoman Li
- Department of Space Radiobiology, Key Laboratory of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Burong Hu
- Department of Space Radiobiology, Key Laboratory of Heavy Ion Radiation Biology and Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
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19
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Rotti H, Mallya S, Kabekkodu SP, Chakrabarty S, Bhale S, Bharadwaj R, Bhat BK, Dedge AP, Dhumal VR, Gangadharan GG, Gopinath PM, Govindaraj P, Joshi KS, Kondaiah P, Nair S, Nair SNV, Nayak J, Prasanna BV, Shintre P, Sule M, Thangaraj K, Patwardhan B, Valiathan MVS, Satyamoorthy K. DNA methylation analysis of phenotype specific stratified Indian population. J Transl Med 2015; 13:151. [PMID: 25952924 PMCID: PMC4438459 DOI: 10.1186/s12967-015-0506-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 04/27/2015] [Indexed: 12/28/2022] Open
Abstract
Background DNA methylation and its perturbations are an established attribute to a wide spectrum of phenotypic variations and disease conditions. Indian traditional system practices personalized medicine through indigenous concept of distinctly descriptive physiological, psychological and anatomical features known as prakriti. Here we attempted to establish DNA methylation differences in these three prakriti phenotypes. Methods Following structured and objective measurement of 3416 subjects, whole blood DNA of 147 healthy male individuals belonging to defined prakriti (Vata, Pitta and Kapha) between the age group of 20-30years were subjected to methylated DNA immunoprecipitation (MeDIP) and microarray analysis. After data analysis, prakriti specific signatures were validated through bisulfite DNA sequencing. Results Differentially methylated regions in CpG islands and shores were significantly enriched in promoters/UTRs and gene body regions. Phenotypes characterized by higher metabolism (Pitta prakriti) in individuals showed distinct promoter (34) and gene body methylation (204), followed by Vata prakriti which correlates to motion showed DNA methylation in 52 promoters and 139 CpG islands and finally individuals with structural attributes (Kapha prakriti) with 23 and 19 promoters and CpG islands respectively. Bisulfite DNA sequencing of prakriti specific multiple CpG sites in promoters and 5′-UTR such as; LHX1 (Vata prakriti), SOX11 (Pitta prakriti) and CDH22 (Kapha prakriti) were validated. Kapha prakriti specific CDH22 5′-UTR CpG methylation was also found to be associated with higher body mass index (BMI). Conclusion Differential DNA methylation signatures in three distinct prakriti phenotypes demonstrate the epigenetic basis of Indian traditional human classification which may have relevance to personalized medicine. Electronic supplementary material The online version of this article (doi:10.1186/s12967-015-0506-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Harish Rotti
- Division of Biotechnology, School of Life Sciences, Manipal University, Manipal, Karnataka, 576104, India.
| | - Sandeep Mallya
- Division of Biotechnology, School of Life Sciences, Manipal University, Manipal, Karnataka, 576104, India.
| | - Shama Prasada Kabekkodu
- Division of Biotechnology, School of Life Sciences, Manipal University, Manipal, Karnataka, 576104, India.
| | - Sanjiban Chakrabarty
- Division of Biotechnology, School of Life Sciences, Manipal University, Manipal, Karnataka, 576104, India.
| | - Sameer Bhale
- Department of Biotechnology, Sinhgad College of Engineering, Pune, Maharashtra, India.
| | - Ramachandra Bharadwaj
- Centre for Clinical Research, Foundation for Revitalization of Local Health Traditions, Bangalore, Karnataka, India.
| | - Balakrishna K Bhat
- Department of Rognidana/Shalyatantra, Shri Dharmasthala Manjunatheshwara College of Ayurveda, Udupi, Karnataka, India.
| | - Amrish P Dedge
- Department of Biotechnology, Sinhgad College of Engineering, Pune, Maharashtra, India.
| | - Vikram Ram Dhumal
- Department of Biotechnology, Sinhgad College of Engineering, Pune, Maharashtra, India.
| | - G G Gangadharan
- Centre for Clinical Research, Foundation for Revitalization of Local Health Traditions, Bangalore, Karnataka, India.
| | - Puthiya M Gopinath
- Division of Biotechnology, School of Life Sciences, Manipal University, Manipal, Karnataka, 576104, India.
| | | | - Kalpana S Joshi
- Department of Biotechnology, Sinhgad College of Engineering, Pune, Maharashtra, India.
| | - Paturu Kondaiah
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, Karnataka, India.
| | - Sreekumaran Nair
- Department of Statistics, Manipal University, Manipal, Karnataka, India.
| | - S N Venugopalan Nair
- Centre for Clinical Research, Foundation for Revitalization of Local Health Traditions, Bangalore, Karnataka, India.
| | - Jayakrishna Nayak
- Department of Rognidana/Shalyatantra, Shri Dharmasthala Manjunatheshwara College of Ayurveda, Udupi, Karnataka, India.
| | - B V Prasanna
- Department of Rognidana/Shalyatantra, Shri Dharmasthala Manjunatheshwara College of Ayurveda, Udupi, Karnataka, India.
| | - Pooja Shintre
- Department of Biotechnology, Sinhgad College of Engineering, Pune, Maharashtra, India.
| | - Mayura Sule
- Department of Biotechnology, Sinhgad College of Engineering, Pune, Maharashtra, India.
| | - Kumarasamy Thangaraj
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Andhra Pradesh, India.
| | - Bhushan Patwardhan
- Interdisciplinary School of Health Sciences, University of Pune, Pune, India.
| | | | - Kapaettu Satyamoorthy
- Division of Biotechnology, School of Life Sciences, Manipal University, Manipal, Karnataka, 576104, India.
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20
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Lee Y, Kim YJ, Choi YJ, Lee JW, Lee S, Cho YH, Chung HW. Radiation-induced changes in DNA methylation and their relationship to chromosome aberrations in nuclear power plant workers. Int J Radiat Biol 2015; 91:142-9. [PMID: 25264146 DOI: 10.3109/09553002.2015.969847] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE We investigated the association between occupational radiation exposure and DNA methylation changes in nuclear power plant workers. We also evaluated whether radiation- induced DNA methylation alterations are associated with chromosome aberrations. MATERIALS AND METHODS The study population included 170 radiation-exposed workers and 30 controls. We measured global, long interspersed nuclear element-1 (LINE-1), and satellite 2 methylation levels in blood leukocyte DNA. The analysis of chromosome aberrations was performed on peripheral lymphocytes. RESULTS Global DNA methylation levels were lower in radiation-exposed workers than in controls. The methylation levels were negatively associated with the recent 1.5-year radiation dose in a multiple linear regression model (β = - 0.0088, p ≤ 0.001); the levels increased proportionally with the total cumulative dose in radiation-exposed workers. LINE-1 methylation levels were higher in radiation-exposed workers than in controls and were significantly associated with the total cumulative radiation dose in a multiple linear regression model (β = - 0.031, p = 0.035). Global DNA methylation levels were also correlated with chromosome aberrations among workers. Workers with low global methylation levels had a higher frequency of chromosome aberrations than did subjects with high global methylation levels. CONCLUSION Occupational exposure to low-dose radiation could affect DNA methylation levels, and the radiation-induced DNA methylation alterations may be associated with chromosome aberrations.
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Affiliation(s)
- Younghyun Lee
- School of Public Health and Institute of Health and Environment, Seoul National University , Gwanak-gu, Seoul , Republic of Korea
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21
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Abstract
Head and neck cancers are characterized by both genetic and epigenetic aberrations. In treating head and neck cancers, ionizing radiation (IR) is an essential modality in either definitive or adjuvant setting. However, radiation-resistant head and neck cancers are not uncommon. The major biological determinator for IR resistance was previously considered at genetic level because DNA is the major target of irradiation damage. However, in head and neck cancers, recent evidence demonstrated epigenetic disturbance after IR, implicating its role in IR resistance. Hence, this chapter intends to establish an in vitro model for investigating DNA methylation changes in IR-resistant head and neck cancer cells. Bisulfite pyrosequencing is the main methodology it introduced.
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22
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Weigel C, Schmezer P, Plass C, Popanda O. Epigenetics in radiation-induced fibrosis. Oncogene 2014; 34:2145-55. [PMID: 24909163 DOI: 10.1038/onc.2014.145] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 04/17/2014] [Accepted: 04/23/2014] [Indexed: 02/06/2023]
Abstract
Radiotherapy is a major cancer treatment option but dose-limiting side effects such as late-onset fibrosis in the irradiated tissue severely impair quality of life in cancer survivors. Efforts to explain radiation-induced fibrosis, for example, by genetic variation remained largely inconclusive. Recently published molecular analyses on radiation response and fibrogenesis showed a prominent role of epigenetic gene regulation. This review summarizes the current knowledge on epigenetic modifications in fibrotic disease and radiation response, and it points out the important role for epigenetic mechanisms such as DNA methylation, microRNAs and histone modifications in the development of this disease. The synopsis illustrates the complexity of radiation-induced fibrosis and reveals the need for investigations to further unravel its molecular mechanisms. Importantly, epigenetic changes are long-term determinants of gene expression and can therefore support those mechanisms that induce and perpetuate fibrogenesis even in the absence of the initial damaging stimulus. Future work must comprise the interconnection of acute radiation response and long-lasting epigenetic effects in order to assess their role in late-onset radiation fibrosis. An improved understanding of the underlying biology is fundamental to better comprehend the origin of this disease and to improve both preventive and therapeutic strategies.
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Affiliation(s)
- C Weigel
- Department of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - P Schmezer
- Department of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - C Plass
- Department of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - O Popanda
- Department of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Song W, Liu Y, Liu Y, Zhang C, Yuan B, Zhang L, Sun S. Increased p16 DNA methylation in mouse thymic lymphoma induced by irradiation. PLoS One 2014; 9:e93850. [PMID: 24747802 PMCID: PMC3991568 DOI: 10.1371/journal.pone.0093850] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 03/07/2014] [Indexed: 11/18/2022] Open
Abstract
DNA methylation is an important part of epigenetics. In this study, we examined the methylation state of two CpG islands in the promoter of the p16 gene in radiation-induced thymic lymphoma samples. The mRNA and protein levels of P16 were significantly reduced in radiation-induced thymic lymphoma tissue samples. Twenty-three CpG sites of the CpG islands in the p16 promoter region were detected, and the methylation percentages of −71, −63, −239, −29, −38, −40, −23, 46 CpG sites were significantly higher in radiation-induced thymic lymphoma tissue samples than those in matched non-irradiated thymus tissue samples. This study provides new evidence for the methylation state of p16 in the radiation-induced thymic lymphoma samples, which suggests that the methylation of these CpG sites in the p16 promoter may reduce its expression in the thymic lymphoma after irradiation.
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Affiliation(s)
| | - Yongzhe Liu
- Department of Toxicology, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Ying Liu
- Department of Toxicology, School of Public Health, Jilin University, Changchun, China
| | - Cong Zhang
- Ministry of Health, Key Laboratory of Radiobiology, Jilin University, Changchun, China, National Laboratory of Medical Molecular Biology, Tsinghua University, Beijing, PR China
| | - Bao Yuan
- College of Animal Sciences, Jilin University, Changchun, China
| | - Lianbo Zhang
- Department of Plastic and Reconstructive Surgery, China-Japan Union Hospital of Jilin University, Changchun, China
- * E-mail:
| | - Shilong Sun
- Ministry of Health, Key Laboratory of Radiobiology, Jilin University, Changchun, China, National Laboratory of Medical Molecular Biology, Tsinghua University, Beijing, PR China
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24
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Newman MR, Sykes PJ, Blyth BJ, Bezak E, Lawrence MD, Morel KL, Ormsby RJ. A single whole-body low dose X-irradiation does not affect L1, B1 and IAP repeat element DNA methylation longitudinally. PLoS One 2014; 9:e93016. [PMID: 24676381 PMCID: PMC3968115 DOI: 10.1371/journal.pone.0093016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 02/27/2014] [Indexed: 11/18/2022] Open
Abstract
The low dose radioadaptive response has been shown to be protective against high doses of radiation as well as aging-induced genomic instability. We hypothesised that a single whole-body exposure of low dose radiation would induce a radioadaptive response thereby reducing or abrogating aging-related changes in repeat element DNA methylation in mice. Following sham or 10 mGy X-irradiation, serial peripheral blood sampling was performed and differences in Long Interspersed Nucleic Element 1 (L1), B1 and Intracisternal-A-Particle (IAP) repeat element methylation between samples were assessed using high resolution melt analysis of PCR amplicons. By 420 days post-irradiation, neither radiation- or aging-related changes in the methylation of peripheral blood, spleen or liver L1, B1 and IAP elements were observed. Analysis of the spleen and liver tissues of cohorts of untreated aging mice showed that the 17-19 month age group exhibited higher repeat element methylation than younger or older mice, with no overall decline in methylation detected with age. This is the first temporal analysis of the effect of low dose radiation on repeat element methylation in mouse peripheral blood and the first to examine the long term effect of this dose on repeat element methylation in a radiosensitive tissue (spleen) and a tissue fundamental to the aging process (liver). Our data indicate that the methylation of murine DNA repeat elements can fluctuate with age, but unlike human studies, do not demonstrate an overall aging-related decline. Furthermore, our results indicate that a low dose of ionising radiation does not induce detectable changes to murine repeat element DNA methylation in the tissues and at the time-points examined in this study. This radiation dose is relevant to human diagnostic radiation exposures and suggests that a dose of 10 mGy X-rays, unlike high dose radiation, does not cause significant short or long term changes to repeat element or global DNA methylation.
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Affiliation(s)
- Michelle R. Newman
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
| | - Pamela J. Sykes
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
| | - Benjamin J. Blyth
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
| | - Eva Bezak
- Department of Medical Physics, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Mark D. Lawrence
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
| | - Katherine L. Morel
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
| | - Rebecca J. Ormsby
- Flinders Centre for Innovation in Cancer, Flinders University and Medical Centre, Bedford Park, South Australia, Australia
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25
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Radiation-induced hypomethylation triggers urokinase plasminogen activator transcription in meningioma cells. Neoplasia 2013; 15:192-203. [PMID: 23441133 DOI: 10.1593/neo.121334] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 12/06/2012] [Accepted: 12/10/2012] [Indexed: 12/27/2022] Open
Abstract
Our previous studies have shown the role of radiation-induced urokinase plasminogen activator (uPA) expression in the progression of meningioma. In the present study, we investigated whether modulation of DNA methylation profiles could regulate uPA expression. Initially, radiation treatment was found to induce hypomethylation in meningioma cells with a decrease in DNA (cytosine-5)-methyltransferase 1 (DNMT1) and methyl-CpG binding domain protein (MBD) expression. However, oxidative damage by H(2)O(2) or pretreatment of irradiated cells with N-acetyl cysteine (NAC) did not show any influence on these proteins, thereby indicating a radiation-specific change in the methylation patterns among meningioma cells. Further, we identified that hypomethylation is coupled to an increase in uPA expression in these cells. Azacytidine treatment induced a dose-dependent surge of uPA expression, whereas pre-treatment with sodium butyrate inhibited radiation-induced uPA expression, which complemented our prior results. Methylation-specific polymerase chain reaction on bisulfite-treated genomic DNA revealed a diminished methylation of uPA promoter in irradiated cells. Transfection with small hairpin RNA (shRNA)-expressing plasmids targeting CpG islands of the uPA promoter showed a marked decline in uPA expression with subsequent decrease in invasion and proliferation of meningioma cells. Further, radiation treatment was found to recruit SP1 transcription factor, which was abrogated by shRNA treatment. Analysis on signaling events demonstrated the activation of MAP kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) in radiation-treated cells, while U0126 (MEK/ERK inhibitor) blocked hypomethylation, recruitment of SP1, and uPA expression. In agreement with our in vitro data, low DNMT1 levels and high uPA were found in intracranial tumors treated with radiation compared to untreated tumors. In conclusion, our data suggest that radiation-mediated hypomethylation triggers uPA expression in meningioma cells.
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26
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Ye S, Yuan D, Xie Y, Pan Y, Shao C. Role of DNA methylation in long-term low-dose γ-rays induced adaptive response in human B lymphoblast cells. Int J Radiat Biol 2013; 89:898-906. [PMID: 23692433 DOI: 10.3109/09553002.2013.806832] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE With widespread use of ionizing radiation, more attention has been attracted to low-dose radiation (LDR); however, the mechanisms of long-term LDR-induced bio-effects are unclear. Here, we applied human B lymphoblast cell line HMy2.CIR to monitor the effects of long-term LDR and the potential involvement of DNA methylation. MATERIALS AND METHODS HMy2.CIR cells were irradiated with 0.032 Gy γ-rays three times per week for 1-4 weeks. Some of these primed cells were further challenged with 2 Gy γ-rays. Cell proliferation, micronuclei formation, gene expression of DNA methyltransferases (DNMT), levels of global genomic DNA methylation and protein expression of methyl CpG binding protein 2 (MeCP2) and heterochromatin protein-1 (HP1) were measured. RESULTS Long-term LDR enhanced cell proliferation and clonogenicity and triggered a cellular adaptive response (AR). Furthermore, global genomic DNA methylation was increased in HMy2.CIR cells after long-term LDR, accompanied with an increase of gene expression of DNMT1 and protein expression of MeCP2 and HP1. After treatment with 5-aza-2'-deoxycytidine (5-aza-dC), a DNA methyltransferase inhibitor, the long-term LDR-induced global genomic DNA hypermethylation was decreased and the AR was eliminated. CONCLUSION Global genomic DNA hypermethylation accompanied with increases of DNMT1 and MeCP2 expression and heterochromatin formation might be involved in long-term LDR-induced adaptive response.
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Affiliation(s)
- Shuang Ye
- Institute of Radiation Medicine, Fudan University , Shanghai , P. R. China
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27
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Antwih DA, Gabbara KM, Lancaster WD, Ruden DM, Zielske SP. Radiation-induced epigenetic DNA methylation modification of radiation-response pathways. Epigenetics 2013; 8:839-48. [PMID: 23880508 DOI: 10.4161/epi.25498] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
DNA methylation can regulate gene expression and has been shown to modulate cancer cell biology and chemotherapy resistance. Therapeutic radiation results in a biological response to counter the subsequent DNA damage and genomic stress in order to avoid cell death. In this study, we analyzed DNA methylation changes at>450,000 loci to determine a potential epigenetic response to ionizing radiation in MDA-MB-231 cells. Cells were irradiated at 2 and 6 Gy and analyzed at 7 time points from 1-72 h. Significantly differentially methylated genes were enriched in gene ontology categories relating to cell cycle, DNA repair, and apoptosis pathways. The degree of differential methylation of these pathways varied with radiation dose and time post-irradiation in a manner consistent with classical biological responses to radiation. A cell cycle arrest was observed 24 h post-irradiation and DNA damage, as measured by γH2AX, resolved at 24 h. In addition, cells showed low levels of apoptosis 2-48 h post-6 Gy and cellular senescence became significant at 72 h post-irradiation. These DNA methylation changes suggest an epigenetic role in the cellular response to radiation.
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Affiliation(s)
- Deborah A Antwih
- Department of Radiation Oncology; Wayne State University and Karmanos Cancer Institute; Detroit, MI USA
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28
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Herceg Z, Lambert MP, van Veldhoven K, Demetriou C, Vineis P, Smith MT, Straif K, Wild CP. Towards incorporating epigenetic mechanisms into carcinogen identification and evaluation. Carcinogenesis 2013; 34:1955-67. [PMID: 23749751 DOI: 10.1093/carcin/bgt212] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Remarkable progress in the field of epigenetics has turned academic, medical and public attention to the potential applications of these new advances in medicine and various fields of biomedical research. The result is a broader appreciation of epigenetic phenomena in the a etiology of common human diseases, most notably cancer. These advances also represent an exciting opportunity to incorporate epigenetics and epigenomics into carcinogen identification and safety assessment. Current epigenetic studies, including major international sequencing projects, are expected to generate information for establishing the 'normal' epigenome of tissues and cell types as well as the physiological variability of the epigenome against which carcinogen exposure can be assessed. Recently, epigenetic events have emerged as key mechanisms in cancer development, and while our search of the Monograph Volume 100 revealed that epigenetics have played a modest role in evaluating human carcinogens by the International Agency for Research on Cancer (IARC) Monographs so far, epigenetic data might play a pivotal role in the future. Here, we review (i) the current status of incorporation of epigenetics in carcinogen evaluation in the IARC Monographs Programme, (ii) potential modes of action for epigenetic carcinogens, (iii) current in vivo and in vitro technologies to detect epigenetic carcinogens, (iv) genomic regions and epigenetic modifications and their biological consequences and (v) critical technological and biological issues in assessment of epigenetic carcinogens. We also discuss the issues related to opportunities and challenges in the application of epigenetic testing in carcinogen identification and evaluation. Although the application of epigenetic assays in carcinogen evaluation is still in its infancy, important data are being generated and valuable scientific resources are being established that should catalyse future applications of epigenetic testing.
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Affiliation(s)
- Zdenko Herceg
- International Agency for Research on Cancer (IARC), 150 Cours Albert Thomas, F-69008 Lyon, France
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Lee SH, Han CH, Kang SM, Park CW. The Regulatory Effects of Radiation and Histone Deacetylase Inhibitor on Liver Cancer Cell Cycle. INTERNATIONAL JOURNAL OF CONTENTS 2012. [DOI: 10.5392/ijoc.2012.8.4.074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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30
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Lee JR, Kim HS. Radiation-induced retroelement-mediated genomic instability. BIOTECHNOL BIOPROC E 2012. [DOI: 10.1007/s12257-012-0008-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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