Molecular mechanisms in hepatocellular carcinoma development.

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world. It usually develops in patients with chronic viral hepatitis, aflatoxin exposure, or excessive alcohol use. Most patients with HCC present with advanced disease and have a poor prognosis. The implementation of antiviral drugs and the availability of a vaccine for hepatitis B should help reduce the incidence of HCC. Considerable effort has now focused on unraveling the molecular pathogenesis of HCC in order to design better treatments, or to prevent the disease altogether. However, so far, the pathogenesis of HCC appears to be quite heterogeneous among patients. In particular, several mechanisms of tumorigenesis seem to be involved, including loss of tumor suppressor gene function, oncogene activation, direct viral effects, DNA methylation, and angiogenesis. It is not clear which events are critical in tumor initiation versus tumor progression. RNA expression arrays and proteomics hold promise to provide further clues about this common and complex cancer.