Effect of silencing Oct4 by specific siRNA on the biological behavior of human bladder cancer cell line EJ

Objective To investigate the effect of small interference RNA (siRNA) silencing Oct4 on the biological behavior of human bladder cancer cell line EJ. Methods EJ cells were divided into three groups: the blank control group, the negative control group, the Oct4-siRNA group. Chemically synthesized siRNA targeting Oct4 (Oct4-siRNA) was transfected into EJ cells with high metastatic potential by lipofectamin 2000. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to semi-quantify the Oct4 mRNA and protein levels. Then proliferation of EJ cells was determined by methyl thiazol tetrazolium (MTT) assay. Acridine orange-ethidium bromide (AO/EB) fluorescent staining was performed to detect apoptosis. The activities of motility and invasion of EJ cells were assessed by cell wound model and transwell chamber invasion assay in vitro, respectively. Results In the Oct4-siRNA group, the Oct4 mRNA and protein levels were down-regulated remarkably (P ＜ 0. 05), the abilities of proliferation were inhibited, the motility and invation of EJ cells were inhibited significantly ( 15.34 ± 1.85vs 63.07 ± 1.73) in vitro, and the apoptosis rate was increased notablely (52. 73% vs 11.70% ) as compared with the negative control group ( P ＜ 0. 05 ). Conclusion Silencing Oct4 could regulate the maligrant biological behaviors of bladder cancer cell line EJ effectively. Key words: RNA interference;  Oct4 gene;  Bladder carcinoma