Sox2 silencing effects on proliferation and apoptosis of bladder cancer cells

Background: Bladder cancer is the sixth most common malignant tumor in men in the world. Our study aimed to investigate the silencing effect of Sox2 on human bladder cancer cell proliferation and apoptosis. Methods: T24 cells were selected and divided in control, scrambled siRNA and Sox2-siRNA groups. Morphological changes in T24 cells were observed after transfection. qRT-PCR and Western blot were performed to observe mRNA and protein expression of apoptosis-related proteins. MTT and flow cytometry were used to detect cell proliferation, cell cycle and apoptosis. Results: Cells grew adhered to the wall and mainly showed a spindle shape with a clear nucleolus in control and scrambled siRNA groups. Increases in cell number in early apoptosis and metaphase cells in apoptosis were observed in Sox2-siRNA group compared with control and scrambled siRNA groups. Sox2-siRNA group showed Sox2 down-regulation relative to that in control and scrambled siRNA groups. There were no significant differences in cell proliferation, cell cycle distribution or apoptosis between control and scrambled siRNA groups. Cell proliferation ability decreased significantly in Sox2-siRNA group, while cell number in G0/G1 stage, cell number of apoptotic cells and caspase-3 and caspase-9 expressions increased significantly. Conclusion: The results showed that Sox2 silencing could inhibit human bladder cancer cell proliferation and promote cell apoptosis.