KIAA0101 (OEACT-1), an expressionally down-regulated and growth-inhibitory gene in human hepatocellular carcinoma

Western blot and tissue array were performed to compare KIAA0101 protein expression level in paired human HCC and non-cancerous liver tissues from the same patients. Investigation of its subcellular localization was done by using dual fluorescence image examination and enriched mitochondrial protein Western blot analysis. The in vitro cell growth curve was used for examing the effect of over-expression of KIAA0101 in HCC cells. FACS was used to analyze the cell cycle pattern in KIAA0101 expression positive (+) and negative (-) cell populations isolated by the pMACSKKII system after KIAA0101 cDNA transfection.Western blot showed KIAA0101 protein expression was down-regulated in HCC tissues as compared with their counterpart non-cancerous liver tissues in 25 out of 30 cases. Tissue array also demonstrated the same pattern in 161 paired samples. KIAA0101 was predominantly localized in mitochondria and partially in nuclei. KIAA0101 cDNA transfection could inhibit the HCC cell growth in vitro. In cell cycle analysis, it could arrest cells at the G1 to S phase transition.KIAA0101 protein expression was down-regulated in HCC. This gene could inhibit the HCC cell growth in vitro and presumably by its blocking effect on cell cycle.Hepatocellular carcinoma (HCC) is one of the most prevalent and lethal cancer in Asia and Africa. The development of HCC is a multi-factor in etiology, multi-step and multi-gene involvement in carcinogenesis and progression. A broad spectrum of genes have been involved in HCC development related to their genetic or epigenetic alteration, including p53[1], p16, p21[2], p27[3], beta-catenin[4], PTEN[5] and Rb etc. Recent studies on functional genomics of HCC have further revealed that a number of genes with novel sequences and unclarified functions were involved in HCC development or progression [6]. Based on cDNA array, we found KIAA0101, now designated as OEACT-1[7], as one of the genes with differential expression in HCC. In recent years, several