RNAi-induced down-regulation of STAT3 expression promotes the apoptosis of Bel-7402 Hepatocarcinoma / 中国医师杂志

ABSTRACT

Objective To explore influence of JAK/STAT3 signaling pathway on the apoptosis of HCC cells.Methods DNA-vector-based RNAi approach silence was used to down-regulate STAT3 expression in Bel-7402 cells.According to the STAT3 cDNA sequence in the GeneBank database,the plasmid pGCsi.U6/neoRFP-STAT3 that was designed for expression of STAT3 siRNA was constructed and synthesized,and then transfected into the Bel-7402 cells with iipofectamine 2000.The apoptotic rate was measured with flow cytometry (FCM) and annexinV/PI apoptosis detection kit staining.The mitochondrial membrane potential (BΨm) was visualized by the JC-1 fluorescence staining and the inverted fluorescence microscope.Moreover,the expression of caspase-3 protein was analyzed by Western blotting.Results The apoptotic ratio of STAT3-siRNA group was (38.82 ± 0.88) ％,which was significantly higher than that in other group [control group (9.22 ± 0.38) ％,scramble-siRNA group (16.47 ± 1.04) ％,P ＜ 0.05].The mitochondrial membrane potential of STAT3-siRNA group observed by the JC-1 fluorescence staining was decreased significantly[(91.33 ± 1.78) ％] and [(89.90 ± 1.92) ％ vs (59.06 ± 1.89) ％,P ＜ 0.05].The Western blot results showed that the protein expression of active caspase-3 in STAT3-siRNA group was significantly higher than other groups (0.48 ± 0.05 vs 0.22 ± 0.04 and 0.26 ± 0.06,P ＜ 0.05).Conclusions STAT3 gene silencing significantly improves the apoptotic effect in the Bel-7402 ceils.