Expression of cell cycle/growth regulator genes in human hepatocellular carcinoma and adjacent normal liver tissues

We investigated the gene expression of the cell cycle/growth regulators in hepatocellular carcinoma (HCC) through the usage of Atlas human cancer array membranes, semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Northern blot. Hybridization of cDNA array membrane was performed with α-32P-labeled cDNA probes synthesized from RNA, isolated from HCC and adjacent non-cirrhotic normal liver. RT-PCR of 24 paired specimens and Northern blot of 4 paired specimens were used to confirm the expression patterns of the cell cycle/growth regulator genes identified by Atlas array hybridization. Among 79 genes related to cell cycle/growth regulators, transcription factor DP2 (TFDP-2) and E2F-3 were up-regulated, whereas dual-specificity mitogen-activated protein kinase kinase 1 (MAPKK1) and cell division protein kinase 3 (CDK3) were down-regulated in HCC. RT-PCR of TFDP-2 gave result consistent with Atlas human cancer cDNA array findings. Northern blot analysis of TFDP-2 and E2F-3 of 4 paired specimens all showed up-regulation in HCC compared to normal liver tissues. The results obtained from Atlas microarray provided for the first time a liver cancer-specific expression profile, which identified the gene expressions comprehensively and systematically. The findings may lead to better understanding of the mechanism of onset and progression of HCC. The rapid and high-throughout method of profiling gene expression by cDNA array provides an overview of the key factors that may be involved in HCC. Some genes are reported for the first time in HCC.