Effects of hepatitis B virus X protein on the induction of cytochrome P450 3A4 in HepG2 cells

Shuang LI; Xiaohui Miao

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Effects of hepatitis B virus X protein on the induction of cytochrome P450 3A4 in HepG2 cells

VernacularTitle:乙型肝炎病毒X蛋白对HepG2细胞中细胞色素P450同工酶3A4诱导的影响
Author: Shuang LI ; Xiaohui MIAO
Publication Type:Journal Article
Keywords: Hepatitis B virus; Viral proteins; Tumor cells,cultured; Cytochrome P450enzyme system; Isoenzymes
From: Chinese Journal of Infectious Diseases 2009;27(8):449-453
CountryChina
Language:Chinese
Abstract: Objective To investigate the effect of hepatitis B virus X protein (HBx) on the induction of eytochrome P450 (CYP) 3A4 by 1α, 25-(OH)2D3 in HepG2 cells in vitro. Methods HepG2 cells were transiently transfected with plasmid pEGFP-N1 (control) or co-transfected with recombinant HBx eukaryotic expression plasmid pcDNA3-X and pEGFP-N1. All HepG2 cells were divided into four groups: control group (without transfection), plasmid pEGFP-N1 transfection group, plasmid pEGFP-N1 transfection plus 1α ,25-(OH)2D3 group, plasmid pcDNA3-X and pEGFP-N1 co-transfection plus 1α ,25-(OH)2D3 group. The expression of CYP3A4 in HepG2 cell was induced by 0.35 μ mol/L 1α ,25-(OH)2D3 for 72 h, and mRNA levels and protein levels of CYP3A4 in the cells were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) assay and Western-blot assay, respectively. The comparison between groups was done by F test. Results CYP3A4 mRNA level in plasmid pcDNA3-X and pEGFP-N1 co-transfection plus 1α ,25-(OH)2D3 group was 1.52 folds of control group, while that in plasmid pEGFP-N1 transfection plus 1α, 25-(OH)2D3 group was 3.97 folds (F= 4.72, P<0. 05). Similarly, intracellular CYP3A4 protein expression in plasmid pcDNA3-X and pEGFP-N1 co-transfection plus 1α , 25-(OH)2D3 group increased to 2.1 folds of control group, while that in plasmid pEGFP-N1 transfection plus 1α,25-(OH)2D3 group increased to 5.9 folds (F=4.68, P<0.05). Conclusion HBx interferes with the induction of CYP3A4 by 1α , 25-(OH)2D3 in HepG2 cell line, which suggests that HBx has suppressive effect on the expression of CYP3A4.