title: Effect of aflatoxin B1 on UDP-glucuronosyltransferase mRNA expression in HepG2 cells.
abstract: Aflatoxin B1 (AFB1) is a potent mycotoxin that induces hepatocellular carcinoma in many animal species, including humans. In this study, we examined the effects of AFB1 on UDP-glucuronosyltransferase (UGT) mRNA expression in HepG2 cells (human hepatocellular carcinoma cell line). The cells were treated with AFB1 for 48 h at a concentration of 10 μM, and their viability (87%) was not significantly different from that of control cells. Reverse transcription polymerase chain reaction (RT-PCR) analysis demonstrated that the mRNAs of four UGT1As (UGT1A1, UGT1A3, UGT1A4 and UGT1A9) and seven UGT2Bs (UGT2B4, UGT2B7, UGT2B10, UGT2B11, UGT2B15, UGT2B17 and UGT2B28) are expressed in HepG2 cells. The mRNAs of aryl hydrocarbon receptor (AhR), pregnane X receptor (PXR), retinoid X receptor (RXR) and glucocorticoid receptor (GR) as transcriptional regulators were also detected. AFB1 significantly increased mRNA levels of UGT1A3, UGT2B10, UGT2B15 and UGT2B17 in HepG2 cells to 2.5-, 2.0-, 1.9- and 1.5-fold, respectively, whereas the mRNA levels of transcriptional regulators were hardly affected by AFB1. These findings suggest that AFB1 induces UGT2B isoforms rather than UGT1A isoforms in HepG2 cells, and that the change may closely contribute to the toxicity of AFB1.
authors: Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan. nhanioka@cc.okayama-u.ac.jp
authors: Nobumitsu
authors: N
authors: Hanioka
authors: Yuko
authors: Y
authors: Nonaka
authors: Keita
authors: K
authors: Saito
authors: Tomoe
authors: T
authors: Negishi
authors: Keinosuke
authors: K
authors: Okamoto
authors: Hiroyuki
authors: H
authors: Kataoka
authors: Shizuo
authors: S
authors: Narimatsu
mesh_terms: D016604:Aflatoxin B1 / Q000633:toxicity*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D014453:Glucuronosyltransferase / Q000235:genetics*; D056945:Hep G2 Cells; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D016604:Aflatoxin B1; D014453:Glucuronosyltransferase