Insulin dominantly suppresses hepatitis B virus gene expression in cultured human hepatoma cells

We have shown previously that insulin suppresses the expression of hepatitis B surface antigen (HBsAg) gene from an endogenous integrated viral genome in cultured human hepatoma Hep3b cells. In this study, we demonstrated that insulin suppresses the viral mRNA transcribed from transiently transfected tandem repeat hepatitis B virus (HBV) dimer DNA or DNA fragment that contains only the major Hbsag gene. Insulin treatment also resulted in a decrease in HBV viral particles produced by the HBV-DNA-transfected cells in a dose-dependent manner. Furthermore, when insulin was simultaneously added with glucocorticoid, which stimulates HBV gene expression, the stimulatory effect of glucocorticoid was completely abolished. Our results suggest that insulin has a dominant negative effect on the HBV gene expression in cultured human liver cells.