Effects of Slug gene silencing by siRNA on increasing sensitivity of pancreatic cancer cell line BxPC-3 to 5-FU-induced apoptosis

OBJECTIVE:To investigate whether Slug gene silencing by siRNA can increase the sensitivity of pancreatic cancer cells (PC) to 5-FU-induced apoptosis.METHODS:pSlug-siRNA and pNeg-siRNA were transfected into BxPC-3 cells by the lipofectamine 2000 methods,and the stable transfected clony was chosen through G418.BxPC-3 cells were divided into three groups:a transfected pSlug-siRNA group,transfected pNeg-siRNA group and control group without transfection BxPC-3 cells,and the three groups were treated with serial concentrations (0.01-100 μmol/L) of 5-FU.The MTT assay was used to observe the inhibitory actions of 5-FU on BxPC-3 cells,and the apoptosis was assessed by Hoechst 33258 and PI dye staining and TUNEL staining.The expression of Slug protein was detected by Western blotting and RT-PCR.RESULTS:The inhibitory action of cell growth was seen in the 3 groups’ cells dealing with 5-FU.It also promoted the occurrence of apoptosis.The IC50 of BxPC-3,BxPC-3/pSlug-siRNA and BxPC-3/pNeg-siRNA were (11.0±2.1),(1.5±0.4) and (9.7±1.3) μmol/L (P0.05).The sensitivity of BxPC-3/pSlug-siRNA to 5-FU was incveased by 7.33 times.5-FU inhibited the proliferation of BxPC-3 cells in a concentration-dependent manner.In pSlug-siRNA cells treated with 5-FU,the apoptosis rate increased greatly and the proliferation rate decreased compared with the control cells and pNeg-siRNA cells dealing with 5-FU.The expression of Slug was decreased greatly compared with pNeg-siRNA cells treated with 5-FU.CONCLUTION:Slug gene silencing by siRNA greatly enhances the sensitivity of BxPC-3 cells to 5-FU-induced apoptosis.