Transcriptome analysis of hepatitis B virus-associated small hepatocellular carcinoma by serial analysis of gene expression

Serial analysis of gene expression (SAGE) is a sequence-based tool that enables quantitative study of comprehensive gene expression profiles. In this Study, we generated a SAGE library of hepatitis B virus (HBV)associated small hepatocellular carcinoma (HCC) and compared it with libraries of normal liver and other organs in order to identify genes which are specifically expressed in HBV-associated small HCC. A total of 18,107 SAGE tags were obtained from the HCC SAGE library. Among the 7,405 unique tags, 240 were significantly overexpressed in HCC compared to normal liver. Seventeen genes were unequivocally matched to SAGE tags which were up-regulated 15-fold or higher in HCC compared to normal liver: four genes (fatty acid desaturase 2, alpha-L-2-fucosidase, testis-specific protein Y-encoded-like 2 and Gon-4-like) were significantly overexpressed in the HCC SAGE library compared to any other SAGE libraries of human normal tissues. The significance of these genes with respect to carcinogenesis and early diagnosis of HCC needs to be elucidated in further studies.