| Theme |
Hepatocarcinogenesis --Mechanism and Prevention |
| Title |
Hepatitis B Virus X Gene and Hepatocarcinogenesis |
| Author |
Katsuro Koike |
Department of Gene Research, The Cancer Institute (JFCR) |
| [ Summary ] |
Studies on hepatitis B virus are now closely relating to the basic studies of growth-related cellular genes or apoptosis of the cell and eventually bring up genes such as p53 tumor suppresser gene on the sunny side. We clarified that X gene of hepatitis B virus suppresses the function of p53 gene and suggested a possible role of X protein as an oncoprotein that works at the early stage of carcinogenesis by disrupting the nuclear localization of p53 protein which functions as a transcriptional regulator. This also suggested the possibility that cytoplasmic retention (nuclear evacuation) of p53 protein by X protein could result in geomic instability of the cell without mutation of p53 gene. Obtained observations agreed well with the fact that mutation of p53 gene could not be detected in the early stage of hepatocellular carcinoma. |