[Transgenic mouse model for hepatocellular carcinoma in human hepatitis B virus infection].

The exact role of hepatitis B virus (HBV) in hepatocarcinogenesis is not known. We generated HBV x gene transgenic mice under the hypothesis that the viral transactivator may alter the host gene expression and lead to the development of hepatocellular carcinoma. The x gene under its own regulatory element caused progressive histopathological changes specifically in the transgenic mouse liver, beginning with multifocal foci of altered hepatocytes, followed by the appearance of neoplasia. This finding shows, for the first time, the direct involvement of HBV in the development of liver cancer. Analyses of events that follow the expression of the x gene suggest that the x gene acts at the early stage of carcinogenesis in the liver.