Differential gene expression of hepatocellular carcinoma using cDNA microarray analysis

A cDNA microarray technique, which allows simultaneous analysis of differential expression of mRNA of over 4000 known human genes, was utilized to study the gene expression in 10 pairs of HCC and nontumorous tissues from ethnic Chinese patients in Hong Kong. A total of 211 genes were found to be highly 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 < or = 0.05 with 95% confidence) on the intensity of each DNA spot of the 10 HCC pairs. Six genes were highly expressed and 10 genes were downregulated in more than 30% of HCC pairs. Results are consistent with other published reports using traditional differential display, subtractive hybridization, or immunohistochemical staining methods. We also detected that beta-actin and glyceraldehyde 3-phosphate dehydrogenase (G3PDH), which have been commonly used as an internal standard control in mRNA expression studies, were highly expressed in HCC when compared with nontumorous tissue. It is concluded that cDNA microarray analysis is an effective method in the detection of differential gene expression in HCC.