Influence of silencing survivin gene by siRNA on the proliferation and apoptosis of colon cancer Caco-2 cells

Objective:To observe the expression of survivin protein in human colon cancer Caco-2 cells and explore the effect of silencing survivin gene by small interfering RNA(siRNA) on the proliferation and apoptosis of Caco-2 cells.Methods:Survivin-targeted siRNA was transfeted into human colorectal cancer Caco-2 cells via LipofectAMINE 2000 mediation.Expression of survivin protein was detected by using immunocytochemistry and Western blotting.Cell proliferation was measured by MTT assay.Cell apoptosis was detected by flow cytometry.Results:Immunohistochemical results indicated that survivin had strongly positive expression in the normal control group,Lip-2000 control group and mismatch control group,and showed weak expression in survivin siRNA interference group.Western blotting indicated that brightness of protein bands in survivin siRNA interference group was significantly lower than those in normal control group,Lip-2000 control group and mismatch control group.Compared with control group,the inhibition rate of cell proliferation was significantly increased in survivin siRNA interference group compared with negative mismatch group(P0.05).Cell proliferation rates were significantly different between 24 h,48 h and 72 h after transfection(P 0.05).FCM showed that diploid peak appeared in survivin siRNA interference group and cell apoptosis rates(9.72%) of survivin siRNA interference group was obviously higher than those of empty control groups(P 0.01).Conclusion:Silencing survivin gene by siRNA can inhibit the proliferation of colorectal cancer cells and induce apoptosis.We speculated that survivin gene may become a new target in gene therapy for colorectal cancer.