[Hepatitis viruses and hepatocarcinogenesis]

Hepatocellular carcinoma (HCC) is one of the most frequent malignancies worldwide. Hepatitis viruses, as the hepatitis virus B (HBV) and hepatitis virus C (HCV), among other environmental factors, are undoubtedly listed in the etiology of HCC. Studies indicate that in the near future viral hepatitis will be of increasing importance in the etiology of HCC.

This review briefly discusses the known carcinogenic effects of HBV and HCV in the light of experimental and human studies.

Data show that viral proteins may directly interfere with gene products responsible for cell proliferation and cell growth, therefore this direct effect may influence the basic mechanism of the cell cycle. Many other signal transduction cascades may be affected as well. Direct integration of HBV viral sequences into the host genome increases the genomic instability. The genomic imbalance allows the development and survival of malignant clones bearing defected genomic information.

HBV and HCV infection induce indirect and direct mechanisms through cellular damage, increased regeneration and cell proliferation, therefore enhancing the development of HCC.