Effects of Cyclooxygenase-2 SiRNA-mediated Gene Silencing on Proliferation and Apoptosis of Human Colon Cancer Cells

Objective To investigate the effect of synthesized COX-2 specific siRNA on the cell proliferation and apoptosis of COX-2 upregulating human colon cancer cells.Methods Human colon cancer cells of the line HT-29 were cultured and transfected with the most optimal COX-2 siRNA by screening.RT-PCR and Western blot were used to detect the expression of COX-2 mRNA and protein.MTT method was used to examine the proliferation of the cells.The apoptosis of the cells was detected by Hoechest staining.Results The expression of COX-2 mRNA and protein in the COX-2 siRNA group decreased remarkably(P0.05),especially after 72 hours culture.The proliferation of HT-29 cells transfected with COX-2 siRNA did not changed significantly 24 hours after the transfection,however,decreased 48 hours and especially after 72 hours and 1 week culture(P0.05),meanwhile,the apoptosis of the HT-29 cells transfected with COX-2 siRNA was significantly higer than that in the cells transfected with the negative COX-2 siRNA and that of the untransfected cells.Conclusion COX-2 is closely related to the proliferation and apoptosis of tumor cells,transfection of the specific siRNA targeting on COX-2 helps inhibit the expression of COX-2,thus inhibiting the growth and enhancing the apoptosis of the tumor cells.