ENHANCED EXPRESSION OF HEPATITIS-B SURFACE-ANTIGEN BY SODIUM-BUTYRATEIN PLC PRF/5 HUMAN HEPATOMA-CELLS/

The effect of butyric acid, a natural fermentation product of colonic bacterial flora, on hepatitis B surface antigen (HBsAg) expression was investigated in HBsAg-positive PLC/PRF/5 human hepatoma cells. By Nor thern blot analysis, the levels of HBsAg mRNA increased dose-dependent ly using sodium butyrate (0-2 mmol/l). In transient chloramphenicol ac etyltransferase plasmid transfection experiments, the HBsAg-preS2 prom oter activity as well as the HBV enhancer 1 activity was stimulated by sodium butyrate, whereas the HBsAg-preS1 promoter activity was not. T hese results indicate that butyric acid functions as a physiological r egulator of HBsAg expression through the portal blood flow and possibl y contributes to increased expression ratio of preS2/S to preS1 polype ptides recognized in persistant HBV infection.