EZH2 silencing by RNA interference inhibits proliferation in bladder cancer cell lines

The Enhancer of Zeste homologue2 gene (EZH2) is frequently expressed at high levels in malignant tumours, including bladder cancer. It functions as a transcriptional regulator to the maintenance of cell identity, cell cycle regulation and oncogenesis. In the study, we detected EZH2 expression in bladder cancer tissues. These results showed EZH2 high expression in bladder cancer tissue at level of transcript and protein compared with normal bladder tissue and EZH2 expression correlated positively with tumour stage and grade. Then, we used RNA interference to inhibit EZH2 expression in bladder cancer EJ cell line. Efficient downregulation of EZH2 resulted in significantly decreased cell proliferation in EJ cells and retarded transition of G(1) phase to S phase. Our data suggest that EZH2 is involved in the tumourigenesis of bladder cancer and EZH2 downregulation contributes to inhibiting malignant growth by retarding cell entrance to S phase.