Comparison of proteome between hepatitis B virus- and hepatitis C virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant cancers closely associated with chronic infection by the hepatitis B virus (HBV) or the hepatitis C virus (HCV) throughout the world. Differential expression of the proteome in HBV- and HCV-associated HCC was investigated to identify any useful biomarkers indicating virus-specific hepatocarcinogenesis.

Twenty-one pairs of specimens (tumorous and surrounding nontumorous liver tissues) were obtained from 21 HCC patients. They were divided into three HCC types by viral markers: 7 hepatitis B surface antigen-positive (B-type HCC), 7 anti-HCV-positive (C-type HCC), and 7 hepatitis B surface antigen-negative and anti-HCV-negative. Total proteins were analyzed by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and alterations in the proteome were examined.

Sixty proteins were identified that show significant changes in the expression level between nontumorous and tumorous tissues. Among these, 14 proteins were commonly changed in all three of the HCC types, but 46 proteins showed a tendency of viral marker specificity.

The identified proteins were classified according to the viral factor as being involved in B-type and C-type HCC. These results suggest strongly that the expression pattern of proteome in HCC tissues is closely associated with etiologic factors. The different protein profiles between B-type and C-type HCC indicate that the pathogenetic mechanisms of hepatocarcinogenesis may be different according to the viral factor, HBV and HCV.