Hepatocellular carcinoma (HCC) is the most frequent form of liver cancer worldwide, and represents the third cause of death. While epidemiological studies have clearly established that hepatitis B virus (HBV) infection is a major risk factor for the development of HCC, the molecular mechanisms underlying virally-induced tumourigenesis are not fully understood. The transcriptional regulatory HBx protein has been described as a multifunctional protein exhibiting numerous activities affecting gene transcription, intracellular signal transduction, cell proliferation, apoptosis and DNA repair. While any or all of the multiple activities of HBx could contribute to hepato-carcinogenesis, HBx is not considered as an oncogene. HBx rather acts as a co-factor of carcinogenesis, through the up-regulation of a large number of cellular genes involved in oncogenesis, proliferation, inflammation and immune response. In this review, we will summarize the current knowledge on the mechanisms involving HBx protein in liver carcinogenesis.
Keywords: HBx protein; carcinoma; hepatitis B virus; liver.