EZH2 Expression and its Correlation with Clinicopathological Features in Patients with Colorectal Carcinoma

Objective: To explore the correlation between the enhancer of zeste homolog 2 (EZH2) expression and clinicopathological features in colorectal cancer patients. Methods: A total of sixty-six patients with colorectal carcinoma were admitted to our general surgery department from January 2011 to December 2014. The EZH2 expression levels in the cancer tissues (CTs) from the 66 patients with colorectal cancer and those in distant normal colorectal tissues from 30 cases were examined through immunohistochemistry and western blotting assays. The relationship between the expression of EZH2 and the clinicopathological features and prognosis of the patients was analyzed. Results: EZH2 in colorectal carcinoma tissues is granularly brown, predominantly expressed and diffused in the nuclei of tumor cells. Positive rates of EZH2 in intestinal CTs and in distant normal intestinal tissues are 62.12% (41/66) and 6.67% (2/30), respectively with significant difference (P < 0.05). Western blotting also confirmed its elevated expression in colorectal CTs. EZH2-positive expression in CTs was related to degree of differentiation, Duke staging, and tumor size (P < 0.05) but was unrelated to the patient's gender, age or tumor site (P > 0.05). The 3-year progression-free survival (PFS) rates of the EZH2-positive group and the EZH2-negative group were 43.8% and 67.5%, respectively. The risk of disease progression of the EZH2-positive patients in the follow-up period was significantly higher than that of the EZH2-negative patients (HR = 2.49, 95% CI = 1.04-4.80, P < 0.05). Conclusion: EZH2 is closely related to colorectal carcinoma development and disease progression, and thus could be used as a tumor biomarker that may indicate prognosis.