Comparison of gene expression profiles between hepatitis B virus- and hepatitis C virus-infected hepatocellular carcinoma by oligonucleotide microarray data on the basis of a supervised learning method.

Gene expression profiles of hepatocellular carcinomas (HCCs) associated with hepatitis B virus (HBV) and hepatitis C virus (HCV) were analyzed and compared. Oligonucleotide microarrays containing >6000 genes and subsequent gene selection by a supervised learning method yielded 83 genes for which expression differed between the two types of HCCs. Expression levels of 31 of these 83 genes were increased in HBV-associated HCCs, and expression levels of the remaining 52 genes were increased in HCV-associated HCCs. The 31 genes up-regulated in HBV-associated HCC included imprinted genes (H19 and IGF2) and genes relating to signal transduction, transcription, and metastasis. The 52 genes up-regulated in HCV-associated HCC included a number of genes responsible for detoxification and immune response. These results suggest that HBV and HCV cause hepatocarcinogenesis by different mechanisms and provide novel tools for diagnosis and treatment of HBV- and HCV-associated HCCs.