GLUCOCORTICOID STIMULATES HEPATITIS-B VIRAL GENE-EXPRESSION IN CULTURED HUMAN HEPATOMA-CELLS

Glucocorticoids have been shown to influence the severity of hepatitis B virus-related chronic hepatitis in human. However, very little is known about the effects of glucocorticoids on hepatitis B virus replication in vitro. In this report, we used a well-differentiated human hepatoma cell line, Hep3B, transfected with hepatitis B virus complementary DNA as a model to show that a glucocorticoid analog, dexamethasone, can directly stimulate the production of HBsAg and HBeAg. Elevation of 3.5-kb pregenomic RNA and all other viral RNAs in the transfected Hep3B cells after dexamethasone treatment supports the hypothesis that glucocorticoids directly stimulate hepatitis B virus gene expression in vitro. The concentration of dexamethasone for its half-maximal stimulatory activity toward HBsAg, HBeAg and all viral transcripts was approximately 10(-8) mol/L, close to the affinity of glucocorticoid receptors to [H-3]-triamcinolone acetonide in Hep3B cells (approximately 10(-8) mol/L). Specific glucocorticoid antagonist RU38486 completely blocked dexamethasone-induced HBV gene expression, suggesting that the stimulatory effect of dexamethasone was mediated through specific glucocorticoid receptors.