Increased Expression of Histone Deacetylase 2 is Found in Human Hepatocellular Carcinoma

Accumulated evidences have established that aberrant regulation of histone deacetylases (HDACs) is one of major causes for development of human malignancies. Mammalian HDACs can be divided into three subclasses consisting of 11 homologous of HDACs and 7 of sirtuins, but little is known about HDAC2 causes for carcinogenesis in solid tumors. Here, in order to investigate the roles of HDAC2 in carcinogenesis of liver cancer progression, we analyzed the expression of HDAC2 in 62 human hepatocellular carcinomas by utilizing Immunohistochemistry. Moderate to strong expression of HDAC2 was found in 54 (87%) out of total 62 tumors. The majority of positive tumors were detected in nucleous, but normal hepatocytes did not express of HDAC2 or showed weak positive staining. Interestingly, we were also noted that HDAC2 expression was appeared to be associated with aggressiveness of the tumors by the fact that HDAC2 expression was observed with significances in high grade tumors (Edmonson grade II, III). Taken together, we found the aberrant expression of HDAC2 in hepatocellular carcinomas, and this suggests that HDAC2 may play an important role in the development of liver cancer.