title: miR-3940-5p enhances homologous recombination after DSB in Cr(VI) exposed 16HBE cell.
abstract: Hexavalent chromium (Cr(VI)) is a well-recognized human carcinogen, yet the molecular mechanisms by which cause human cancer are still not well understood. MicroRNAs (miRNAs), which are small non-coding RNAs, are involved in carcinogenesis and DNA damage repair. Previous occupational population study showed that hexavalent chromium (Cr(VI)) downregulated plasma miR-3940-5p level, and a low miR-3940-5p level was associated with high XRCC2 expression in lymphocytes, indicating that miR-3940-5p maybe play a protective effect in Cr(VI) induced DNA damage. Here we investigated miR-3940-5p expression and its roles in DNA repair in Cr(VI)-treated 16HBE cells. miR-3940-5p change was detected by qRT-PCR. Rad51 foci formation and double strand break (DSB) were investigated to assess homologous recombination repair (HR) capacity by Immunofluorescent assay and Neutral Comet assay. XRCC2 expression was also evaluated after miRNA oligonucleotides transfection using Western blot. Cr(VI) treatment suppressed miR-3940-5p level in 16HBE cells. miR-3904-5p mimic downregulated XRCC2 expression. As a result, the formation of Rad51-foci was inhibited and DSB repair was prolonged. The results indicate that miR-3940-5p plays a protective effect in Cr(VI) induced DNA damage.
authors: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, China.
authors: Yang
authors: Y
authors: Li
authors: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, China.
authors: Guiping
authors: G
authors: Hu
authors: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, China.
authors: Ping
authors: P
authors: Li
authors: Beijing Municipal Institute of Labor Protection, Beijing Academy of Science and Technology, Beijing, China.
authors: Shichuan
authors: S
authors: Tang
authors: Center for Disease Control and Prevention, Jinan City, Shandong Province, China.
authors: Ji
authors: J
authors: Zhang
authors: Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, China. Electronic address: jiaguangjia@bjmu.edu.cn.
authors: Guang
authors: G
authors: Jia
mesh_terms: D002460:Cell Line; D002857:Chromium / Q000633:toxicity*; D004249:DNA Damage / Q000187:drug effects / Q000502:physiology; D004260:DNA Repair / Q000187:drug effects / Q000502:physiology; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D059765:Homologous Recombination / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D035683:MicroRNAs / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; C581631:MIRN3940 microRNA, human; D035683:MicroRNAs; C113187:XRCC2 protein, human; D002857:Chromium; C074702:chromium hexavalent ion
keywords: DNA damage; Hexavalent chromium; miRNA