Hepatitis viruses and hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is among the most frequent malignancies worl dwide. Hepatitis viruses, such as the hepatitis B virus (HBV) and hepatitis C virus (HCV) are undoubtedly listed in the etiology of HCC. Studies show that, in the near future, viral hepatitis will carry increasing weight in t he etiology of HCC. This review briefly discusses the known carcinogenic ef fects of HBV and HCV in the light of experimental and human studies. The da ta show that viral proteins may directly interfere with gene products respo nsible for cell proliferation and cell growth. Many other signal transducti on cascades may be affected as well. Direct integration of HBV viral sequen ces into the host genome increases the genomic instability. The genomic inb alance allows the development and survival of malignant clones bearing defe cted genomic information. HBV and HCV infection induces indirect and direct mechanisms through cellular damage, increased regeneration and cell prolif eration, therefore enhancing the development of HCC. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.