Differential gene expression of hepatocellular carcinoma using cDNA microarray analysis

A cDNA microarray technique, which allows simultaneous analysis of differen tial expression of mRNA of over 4000 known human genes, was utilized to stu dy the gene expression in 10 pairs of HCC and nontumorous tissues from ethn ic Chinese patients in Hong Kong. A total of 211 genes were found to be hig hly expressed and 147 genes were downregulated in more than 1 out of 10 of the HCC pairs. The results were significant by two-tailed Wilcoxon test (P less than or equal to 0.05 with 95% confidence) on the intensity of each DN A spot of the 10 HCC pairs. Six genes were highly expressed and 10 genes we re downregulated in more than 30% of HCC pairs. Results are consistent with other published reports using traditional differential display, subtractiv e hybridization, or immunohistochemical staining methods. We also detected that beta -actin and glyceraldehyde 3-phosphate dehydrogenase (G3PDH), whic h have been commonly used as an internal standard control in mRNA expressio n studies, were highly expressed in HCC when compared with nontumorous tiss ue. It is concluded that cDNA microarray analysis is an effective method in the detection of differential gene expression in HCC.