Expression of stemness gene Bmi-1 in hepatocellular carcinoma

A95

Bmi-1, one of the Polycomb group genes, is involved in the self-renewing maintenance of stem cells. This study investigated the expression of Bmi-1 in hepatocarcinogenesis. Bmi-1 expression was examined in five HCC cell lines and in 100 patients with 154 nodules (46 well-diff., including 20 early; 84 mod. diff.; and 24 poorly diff. HCCs). The expression of Bmi-1 was determined by qRT-PCR, immunoblotting, and immunohistochemistry. Bmi-1 was highly expressed in most well-diff. type HCC cell lines and also showed that Bmi-1 was up-regulated in tumor regions compared to background liver in clinical cases. Bmi-1 protein was distributed in small dot pattern inside the nucleus area was considered as a positive expression, and it was observed in 40 of 46 well- (including 20 of 23 early), in 50 of 84 mod., and in 11 of 24 poorly diff. HCC, but it was not observed in background liver. The Bmi-1 gene was expressed in the HCC region, and in particular it was highly expressed in early and well-diff. HCC. These findings suggest that Bmi-1 may contribute to early hepatocarcinogenesis and may function as a novel marker for distinguishing tumor and non-tumor regions in the early stage of HCC.
 #