Effect of down-regulating survivin expression by RNAi on growth suppression and promotion on apoptosis of human hepatocellular carcinoma cells

Objective To explore the effect of down-regulating survivin expression by RNAi on growth suppression and promotion on apoptosis of human hepatocellular carcinoma cells,in order to supply an effective target and technique for liver cancer gene therapy.Methods The recombinant plasmid of pSU6-si-survivin was constructed,which was transfected into Bel7402 cells.Mock group,negative group and treated group were set up.Using MTT assay the proliferation of transfected cells was investigated,the survivin protein expression level was determined by Western blotting and immunohistochemical staining.Transcription of survivin was detected by semi-quantitative RT-PCR.Flow cytometry(FCM) and AO/EB double dyeing were used to examine apoptosis in transfected cells.Results MTT assay demonstrated that the cell growth inhibition rates(%) of transfected cells in treated group at 24,48 and 72 h were 21.43±1.67,39.07±3.80,and 59.72±7.05,there were significant differences compared with negative group(P0.01).The results of RT-PCR and Western blotting showed that the mRNA and protein levels of survivin declined markedly in transfected cells,the ratio of expression product to β-actin in treated group had significant differences compared with negative group and mock group(P0.01).The results of FCM indicated that the cells in treated group were inhibited in G0/G1 stage,the apoptotic rate was 20.65%±1.28%,there were significant differences compared with mock group and negative group(P0.01).AO/EB double dyeing showed that the most cells in treated group were in early or middle stage apoptosis.Conclusion The recombinant plasmid of pSU6-si-survivin can significantly inhibit the expression of survivin gene in Bel7402 cells,and suppress cell growth and induce apoptosis,so survivin may act as an important target to treat human hepatocellular carcinoma.