title: MicroRNA regulation of DNA repair gene expression in 4-aminobiphenyl-treated HepG2 cells.
abstract: We examined the role of miRNAs in DNA damage response in HepG2 cells following exposure to 4-aminobiphenyl (4-ABP). The arylamine 4-ABP is a human carcinogen. Using the Comet assay, we showed that 4-ABP (18.75-300μM) induces DNA damage in HepG2 cells after 24h. DNA damage signaling pathway-based PCR arrays were used to investigate expression changes in genes involved in DNA damage response. Results showed down-regulation of 16 DNA repair-related genes in 4-ABP-treated cells. Among them, the expression of selected six genes (UNG, LIG1, EXO1, XRCC2, PCNA, and FANCG) from different DNA repair pathways was decreased with quantitative real-time PCR (qRT-PCR). In parallel, using the miRNA array, we reported that the expression of 27 miRNAs in 4-ABP-treated cells was at least 3-fold higher than that in the control group. Of these differential 27 miRNAs, the most significant expression of miRNA-513a-5p and miRNA-630 was further validated by qRT-PCR, and was predicted to be implicated in the deregulation of FANCG and RAD18 genes, respectively, via bioinformatic analysis. Both FANCG and RAD18 proteins were found to be down-regulated in 4-ABP-treated cells. In addition, overexpression and knockdown of miRNA-513a-5p and miRNA-630 reduced and increased the expression of FANCG and RAD18 proteins, respectively. Based on the above results, we indicated that miRNA-513a-5p and miRNA-630 could play a role in the suppression of DNA repair genes, and eventually lead to DNA damage.
authors.affiliation: Department of Life Sciences, National Central University, Jhongli, Taiwan.
authors.forename: Lin Chen
authors.initials: LC
authors.lastname: Huan
authors.affiliation: Department of Applied Chemistry, Fooyin University, Kaohsiung, Taiwan.
authors.forename: Jong-C
authors.initials: JC
authors.lastname: Wu
authors.affiliation: Department of Life Sciences, National Central University, Jhongli, Taiwan.
authors.forename: Bin-Hao
authors.initials: BH
authors.lastname: Chiou
authors.affiliation: Department of Medical Technology, Yuanpei Institute of Science and Technology, Hsin-Chu, Taiwan.
authors.forename: Chin-Hui
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Institute of Systems Biology and Bioinformatics, National Central University, Jhongli, Taiwan.
authors.forename: Nianhan
authors.initials: N
authors.lastname: Ma
authors.affiliation: Department of Life Sciences, National Central University, Jhongli, Taiwan.
authors.forename: Chi Yao
authors.initials: CY
authors.lastname: Chang
authors.affiliation: Graduate Institute of Statistics, National Central University, Jungli, Taiwan.
authors.forename: Yi-Kuang
authors.initials: YK
authors.lastname: Tsen
authors.affiliation: Department of Life Sciences, National Central University, Jhongli, Taiwan. Electronic address: osycchna@ksts.seed.net.tw.
authors.forename: Ssu Ching
authors.initials: SC
authors.lastname: Chen
mesh_terms: D000611:Aminobiphenyl Compounds / Q000633:toxicity*; D015153:Blotting, Western; D002273:Carcinogens / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D003470:Culture Media; D004249:DNA Damage; D004260:DNA Repair / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D017403:In Situ Hybridization; D012313:RNA / Q000096:biosynthesis / Q000302:isolation & purification; D012333:RNA, Messenger / Q000096:biosynthesis / Q000502:physiology*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000611:Aminobiphenyl Compounds; D002273:Carcinogens; D003470:Culture Media; D012333:RNA, Messenger; C006757:4-biphenylamine; D012313:RNA
keywords: DNA damage; DNA repair; miRNA-513a-5p; miRNA-630