Abstract: Objective To study the expression of EZH2 gene in hepatocellular carcinoma (HCC) and its clinical roles. Methods Reverse transcription-polymerase chain reaction (RT-PCR)， immunohistochemistry, and Western blotting were used to detect the EZH2 mRNA and EZH2 protein expression in the tumor samples and surrounding non-cancerous liver samples，and then investigated the correlation between expression status and various clinicopathological parameters. Results The positive rate of EZH2 mRNA in HCC was 619%(26/42),the EZH2 mRNA positive rate in surrounding non-cancerous liver samples was 28.6% (12/42).EZH2 mRNA expression in HCC was significantly higher than that in surrounding noncancerous liver samples (EM>P/EM><0.01). Immunohistochemistry showed EZH2 protein expression in HCC was also significantly higher than that in surrounding non-cancerous liver samples(25/42 vs 9/42, EM>P/EM><0.01). Western blotting showed that EZH2 protein was expressed in all selected 18 HCC and surrounding noncancerous liver cases.The quantity of EZH2 protein in HCC was much more than that in surrounding non-cancerous tissue(0.90±0.30 vs 0.36±0.21，EM>P/EM><0.01).As the EZH2 and pathologic parameters were analysed, it was found that EZH2 mRNA transcript was elevated in poorly differentiated HCC compared with wellmoderately differentiated HCC,but there were no statistically significant correlations between EZH2 mRNA and tumor size, and intrahepatic/ extrahepatic metastasis. No significant difference was found between EZH2 protein and tumor size, differentiation, and intrahepatic/ extrahepatic metastasis.[WTHZ]Conclusion The exp

Key words: Hepatocellular carcinoma, EZH2 gene, RT-PCR, Immunohistochemistry, Western blotting, Human