Hepatitis B virus X gene induces human telomerase reverse transcriptase mRNA expression in cultured normal human cholangiocytes

摘要

AIM: To study the transcriptional regulation of human telomerase reverse transcriptase (hTERT) mRNA in normal human cholangiocytes (HBECs) after hepatitis B virus X (HBx) gene transfection and to elucidate the possible mechanism of HBV infection underlying cholangiocarcinoma.METHODS: HBECs were cultured in vitroand co-transfected with a eukaryotic expression vector containing the HBx coding region and a doning vector containing coding sequences of enhanced green fluorescent protein (EGFP) using lipidmediated gene transfer. The transfection efficiency was determined by the expression of EGFP. The expressions of hTERT mRNA and HBx protein in HBECs were detected by RT-PCR and immunocytochemical stain, respectively.RESULTS: The transfection efficiencies were about 15% for both HBx gene expression plasmid and empty vector.No hTERT mRNA was expressed in HBECs when transfected with OPTI-NEN medium and empty vector, but a dramatic increase was observed for hTERT mRNA expression in HBECs when transfected with HBx expression vector. HBx proyein was only expressed in HBECs when transfected with HBx expression vector.CONCLUSION: HBx transfection can activate thet ranscriptional expression of hTERT mRNA. Cis-activation of hTERT mRNA by HBx gene is the primary mechanism underlying the proliferation, differentiation and tumorigenesis of biliary epithelia.