Potential Molecular Mechanisms of Viral Liver Carcinogenesis

Hepatocellular carcinoma is one of the most common malignant tumors worldwide. The geographic prevalence of HCC is largely variable and this reflects the different distribution of possible etiological factors. Liver cirrhosis is the major determinant of neoplastic transformation (1). The strong association between chronic HBV and HCV infection and developement of HCC is widely demonstrated by epidemiological studies (2,3) but the exact mechanism by which malignant trasformation occurs remains still unclear. HBV might exert a direct role in liver carcinogenesis by a combination of different non exclusive effects as DNA integration (4) and transactivating activity of HBX and truncated pre-S2/S proteins (5,6). Concerning HCV related liver oncogenesis, it is still obscure whether HCV might exert, in addition to inducing cirrhosis, a direct effect in malignant transformation. The evidence that HCV persists and replicate in HCC developing in absence of cirrhosis (7) may be a basis for further molecular studies on the potential oncogenic effect of HCV.