Relationship between Proliferative Activity and Expression of HBcAg and p53 Protein in Hepatocellular Carcinoma and Surrounding Nontumorous Liver

Paik, So Ya; Kim, Ho Guen; Park, Chan Il

Abstract

In an attempt to discover the factors contributing to the increased proliferative activity in hepatocytes and subsequent development of HCC, the proliferative activity of hepatocytes was compared with the size of regenerative nodules and HBcAg expression status in the surrounding nontumorous liver of 45 surgically resected hepatocellular carcinomas, including 34 HBV related ones. In the tumor, the difference in proliferative activity and the histological grade was analyzed in terms of p53 gene alteration. The proliferative activity was assessed by immunohistochemical methods using Ki-67 monoclonal antibody. HBcAg expression in the surrounding nontumorous liver correlated with both the inflammatory and proliferative activity of hepatocytes (p<0.05). p53 overexpression was associated with high proliferative activity and aggressive phenotype of tumor. No correlation was observed between the proliferative activity of hepatocytes and the size of regenerative nodules in cirrhosis (p>0.05). p53 overexpression was not evident in surrounding nontumorous liver including cirrhosis. In conclusion, the above results are in line with the view that hepatic carcinogenesis is a mutistep, progressive process. In the initial stage, chronic cellular injury incurred by immumologic reaction against HBcAg seems to play a pivotal role in increased cellular regeneration. However, once transformation of hepatocytes occur the major contributor to tumor growth seems to be alteration in p53 tumor suppresor gene.