Abstract:

Objective To investigate the effect of speckle-type POZ protein （SPOP） on the biological behavior of bladder cancer T24by small interfering RNA （siRNA）. Methods The sequences of siRNA-1 and siRNA-1 together with LipofectamineTM 2000 were transfected into T24 cell lines to silence the expression of SPOP. T24 cells were divided into negative control group， siRNA1 and siRNA2 group. Quantitative real time polymerase chain reaction （qRT-PCR） and Western blotting method were used to detect the mRNA and protein levels of SPOP in each group at 48 h after transfection. Cell proliferation assay kit （CCK-8） was used to check the cell proliferation activity and the proliferation and migration were observed by Transwell migration assay and wound healing assay. Results The relative expression of SPOP mRNA were 1.012±0.025， 0.281±0.023 and 0.274±0.053 in control group， siRNA1 group and siRNA2 group. The relative expression of SPOP protein were 0.712±0.153，0.358±0.073 and 0.317±0.084 in control group， siRNA1 group and siRNA2 group. Both the mRNA and protein levels of SPOP were lower in siRNA1 group and siRNA2 group than control group（P＜0.05）. There was no significant difference in mRNA SPOP and protein levels between siRNA1 and siRNA2 groups （P＞0.05）. Compared with the control group，the proliferation activity of siRNA1 group and siRNA2 group were significantly increased，and the proliferation rates of siRNA2 and siRNA1 groups increased with the prolongation of transfection time（P＜0.05）. Results of Transwell migration test showed that the number of membrane penetrating cells were 128.6±9.3 and 134.5±8.6 in siRNA1 group and siRNA2 group， higher than 92.5±8.4 in control group with statistical significance （P＜0.05）. Results of the scratch test showed that the wound healing rates were （89.1±4.5）% and （93.7±5.1）% in siRNA1 group and siRNA2 group， higher than （32.6±2.8）% in control group with statistical significance（P＜0.05）.
Conclusion SPOP may play a tumor suppressor gene in the malignant behavior of bladder cancer via inhibiting proliferation and migration.