Induction of murine colon carcinoma apoptosis by small interference RNA targeted to Survivin

Objective To screen small interference RNAs that could inhibit Survivin expression and to explore the effect of RNA interference of Survivin on apoptosis of routine colon carcinoma.Meth- ods Three siRNA target sequences for Survivin were designed and the siRNA expression cassettes were prepared by PCR.The siRNA expression cassettes were transfected into 293T cells along with Survivin and green fluorescent protein fusion gene expression plasmid to select more effective siRNA.The expres- sion vector of an effective siRNA was constructed and transfected into murine colon carcinoma CT26 ceils.The expression of Survivin was detected by real-time fluorescent quantitative polymerase chain reac- tion and Western blot.The apoptosis of CT26 cells was assayed by TUNEL and flow cytometry through FITC-Annexin V/PI dying methods.Results A candidate siRNA that down-regulated the expression of Survivin in 293T ceils was selected,which could efficiently inhibitthe expression of Survivin mRNA and protein in CT26 cells.The apoptosis of CT26 cells was significantly increased.TUNEL revealed that amount of apoptosis cells was(60.13±5.71)in siRNA groups and(5.47±0.63)in controls at 48th h after trausfection.FCM demonstrated that the apoptosis rate was 2.1%,4.9%,11.7% and 32.6% at 24th,48th,72nd and 96th h after transfection respectively,which of controls were lower than 1.5%. Conclusion SiRNA could suppress the expression of Survivin and induce CT26 call apoptosis effectively, which lay a foundation for further research on treatment of malignant tumor targeting to Survivin.