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Diet-induced obesity modulates epigenetic responses to ionizing radiation in mice. PLoS One 2014; 9:e106277. [PMID: 25171162 PMCID: PMC4149562 DOI: 10.1371/journal.pone.0106277] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 08/05/2014] [Indexed: 01/16/2023] Open
Abstract
Both exposure to ionizing radiation and obesity have been associated with various pathologies including cancer. There is a crucial need in better understanding the interactions between ionizing radiation effects (especially at low doses) and other risk factors, such as obesity. In order to evaluate radiation responses in obese animals, C3H and C57BL/6J mice fed a control normal fat or a high fat (HF) diet were exposed to fractionated doses of X-rays (0.75 Gy ×4). Bone marrow micronucleus assays did not suggest a modulation of radiation-induced genotoxicity by HF diet. Using MSP, we observed that the promoters of p16 and Dapk genes were methylated in the livers of C57BL/6J mice fed a HF diet (irradiated and non-irradiated); Mgmt promoter was methylated in irradiated and/or HF diet-fed mice. In addition, methylation PCR arrays identified Ep300 and Socs1 (whose promoters exhibited higher methylation levels in non-irradiated HF diet-fed mice) as potential targets for further studies. We then compared microRNA regulations after radiation exposure in the livers of C57BL/6J mice fed a normal or an HF diet, using microRNA arrays. Interestingly, radiation-triggered microRNA regulations observed in normal mice were not observed in obese mice. miR-466e was upregulated in non-irradiated obese mice. In vitro free fatty acid (palmitic acid, oleic acid) administration sensitized AML12 mouse liver cells to ionizing radiation, but the inhibition of miR-466e counteracted this radio-sensitization, suggesting that the modulation of radiation responses by diet-induced obesity might involve miR-466e expression. All together, our results suggested the existence of dietary effects on radiation responses (especially epigenetic regulations) in mice, possibly in relationship with obesity-induced chronic oxidative stress.
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Leung CM, Chen TW, Li SC, Ho MR, Hu LY, Liu WS, Wu TT, Hsu PC, Chang HT, Tsai KW. MicroRNA expression profiles in human breast cancer cells after multifraction and single-dose radiation treatment. Oncol Rep 2014; 31:2147-56. [PMID: 24626680 DOI: 10.3892/or.2014.3089] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 02/27/2014] [Indexed: 11/05/2022] Open
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that contribute to modulating signaling pathways after radiation exposure and have emerged as a potential therapeutic target or biomarker in the radiation response of cancer. Exposing breast cancer cells to single-dose (SD) or multifractionated (MF) radiation may affect the cells differently. However, the roles of miRNAs in breast cancer cells after the response to SD or MF is not thoroughly understood. Therefore, the purpose of the present study was to comprehensively investigate the response of miRNAs in MDA-MB-361 by using various radiation exposing protocols. Our results revealed that only a small fraction of miRNAs exhibiting differential expressions (>1.5‑fold) was identified after MDA-MB-361 cells were exposed to SD (10 Gy) or MF radiation (2 Gy x 5 MF). In addition, we observed that several miRNAs in the MDA-MB-361 cells frequently exhibited differential responses to various types of radiation treatment. Among these miRNAs, the expression levels of an oncogenic miR-17-92 cluster increased following SD radiation treatment. Conversely, miR-19a-3p, miR-20a-5p, and miR-19b-3p expressions were inhibited by >1.5-fold in the following MF treatment. Further analysis of the miR-17-92 cluster expression levels revealed that miR-17, miR-18a, miR-19a/b and miR-20a were significantly overexpressed and miR-92a was downregulated in breast cancer. Functional annotation demonstrated that target genes of the miR-17-92 cluster were predominantly involved in the regulation of radiation-associated signal pathways such as mitogen-activated protein kinase (MAPK), ErbB, p53, Wnt, transforming growth factor-β (TGF-β), mTOR signaling pathways and cell cycles with an FDR <0.05. Overall, the results of the present study revealed distinct differences in the response of miRNAs to SD and MF radiation exposure, and these radiation-associated miRNAs may contribute to radiosensitivity and can be used as biomarkers for radiotherapy.
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Affiliation(s)
- Chung-Man Leung
- Department of Radiation Oncology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, R.O.C
| | - Ting-Wen Chen
- Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan, R.O.C
| | - Sung-Chou Li
- Genomics and Proteomics Core Laboratory, Department of Medical Research, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan, R.O.C
| | - Meng-Ru Ho
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan, R.O.C
| | - Ling-Yueh Hu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, R.O.C
| | - Wen-Shan Liu
- Department of Radiation Oncology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, R.O.C
| | - Tony T Wu
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, R.O.C
| | - Ping-Chi Hsu
- Department of Safety, Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung, Taiwan, R.O.C
| | - Hong-Tai Chang
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, R.O.C
| | - Kuo-Wang Tsai
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, R.O.C
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Leung CM, Li SC, Chen TW, Ho MR, Hu LY, Liu WS, Wu TT, Hsu PC, Chang HT, Tsai KW. Comprehensive microRNA profiling of prostate cancer cells after ionizing radiation treatment. Oncol Rep 2014; 31:1067-78. [PMID: 24452514 PMCID: PMC3926670 DOI: 10.3892/or.2014.2988] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 12/23/2013] [Indexed: 12/19/2022] Open
Abstract
MicroRNAs (miRNAs) are small, non-coding RNAs that negatively regulate gene expression and have emerged as potential biomarkers in radiation response to human cancer. Only a few miRNAs have been identified in radiation response to prostate cancer and the involvement of the radiation-associated miRNA machinery in the response of prostate cancer cells to radiation is not thoroughly understood. Therefore, the purpose of the present study was to comprehensively investigate the expression levels, arm selection preference and isomiRs of radiation-response miRNAs in radiation-treated PC3 cells using a next-generation sequencing (NGS) approach. Our data revealed that the arm selection preference and 3′ modification of miRNAs may be altered in prostate cancer after radiation exposure. In addition, the proportion of AA dinucleotide modifications at the end of the read gradually increased in a time-dependent manner after PC3 radiation treatment. We also identified 6 miRNAs whose expression increased and 16 miRNAs whose expression decreased after exposure to 10 Gy of radiation. A pathway enrichment analysis revealed that the target genes of these radiation-induced miRNAs significantly co-modulated the radiation response pathway, including the mitogen-activated protein kinase (MAPK), Wnt, transforming growth factor-β (TGF-β) and ErbB signaling pathways. Furthermore, analysis of The Cancer Genome Atlas (TCGA) database revealed that the expression of these radiation-induced miRNAs was frequently dysregulated in prostate cancer. Our study identified radiation-induced miRNA candidates which may contribute to radiosensitivity and can be used as biomarkers for radiotherapy.
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Affiliation(s)
- Chung-Man Leung
- Department of Radiation Oncology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, R.O.C
| | - Sung-Chou Li
- Genomics and Proteomics Core Laboratory, Department of Medical Research, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan, R.O.C
| | - Ting-Wen Chen
- Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan, R.O.C
| | - Meng-Ru Ho
- Genomics Research Center, Academia Sinica, Taipei, Taiwan, R.O.C
| | - Ling-Yueh Hu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, R.O.C
| | - Wen-Shan Liu
- Department of Radiation Oncology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, R.O.C
| | - Tony T Wu
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, R.O.C
| | - Ping-Chi Hsu
- Department of Safety, Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung, Taiwan, R.O.C
| | - Hong-Tai Chang
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, R.O.C
| | - Kuo-Wang Tsai
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, R.O.C
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