Expression Of EZH2 In Human Gastric Carcinoma And Its Relationship To Cell Proliferation

Objective To investigate the expression of EZH2 in human gastric carcinoma, and the relationship between its expression and the clinicopathological parameters in human gastric carcinoma.Methods The reverse transcriptase-polymerase chain reaction(RT-PCR) was used for detection of EZH2 mRNA level in 30 cases of primary gastric carcinoma tissues that were diagnosised through endoscopic and pathologic methods compared to the paracancerous tissues. The expression of EZH2 protein and Ki-67 was examined by immunohistochemistry S-P staining method in a series of 76 human primary gastric carcinomas and 45 cases of nomal tissues adjacent to tumor.Results1. The EZH2 mRNA lever was 0.994±0.129 in gastric carcinoma tissues, whileas that was 0.332±0.080 in the paracancerous tissues (P =0.000).2. The positive rates of expression of EZH2 protein were 51.3%(39/76) in human gastric carcinoma. No expression of EZH2 was detected in the 45 cases normal tissues adjacent to tumor (0/45).3. The EZH2 protein expression level was significantly positively correlated with tumor size, depth of invasion, lymph node metastasis and TNM staging ( P＜0.05), but there was no significant difference between EZH2 protein and other clinicopathological features such as sex, age, tumor status and differentiation (P＞0.05).4. Expression of EZH2 was closely positively correlated with that of Ki-67 in human gastric carcinomas (r=O.335, p＜0.05).5. The five-year survival rate of patients was significantly higher in EZH2 negative group than in EZH2 positive group (54.1% vs 30.8% P＜0.05).Conclusions1. Expression of EZH2 mRNA and protein are highly up-regulated in gastric carcinoma.2. Expression of EZH2 protein has the association with tumor size, depth of invasion, lymph node metastasis and TNM staging ( P＜0.05 ), no correlation was found with sex, age, tumor position and differentiation status (P＞0.05), which suggested that up-regulated expression of EZH2 protein may be helpful for the diagnosis of gastric carcinoma.3. EZH2 was close]y related with tumor proliferation.