STAT3表达下调对人肝癌细胞增殖的影响及相关分子机制

The effect of down-regulating STAT3 expression on growth of human hepatocellular carcinoma cells and its molecular mechanism

目的探讨RNA干扰技术下调信号转导和转录激活因子(STAT)3基因表达对人肝癌细胞增殖的抑制作用及具体机制。方法构建重组质粒PLKO-1-shRNA-STAT3,通过RT-PCR、Westernblot检测STAT3表达的变化;采用流式细胞术检测细胞周期来反映细胞的增殖状态;通过RT-PCR、Westernblot检测Bcl-2和Survivin表达水平的变化。结果转染了PLKO-1-shRNA-STAT3重组质粒的肝癌细胞,STAT3表达明显下调,流式细胞术检测显示S期细胞减少,G0/G1期细胞增加(P<0.05),Bcl-2和Survivin基因的mRNA及蛋白表达水平明显低于对照组。结论 RNA干扰技术明显下调细胞内STAT3蛋白的表达,进而下调Bcl-2和Survivin的表达水平,诱导细胞凋亡。

Objective To study the mechanism and the suppression effect on human hepatocellular carcinoma cell by down-regu- lating the expression of signal transducers and activators of transcription（STAT）3 with RNA interference technology. Methods Construct recombinant plasmid PLKO-I-shRNA-STAT3, and detect STAT3 expression by RT-PCR and Western blot, detect cellu- lar cycle by flow cytometry which reflect the cell proliferation. Detect Bcl-2 and Survivin expression by RT-PCR and Western blot. Results In hepatoma cells transfected with PLKO-I-shRNA-STAT3 recombinant plasmid,STAT3 expression was significantly re- duced, flow cytometry analysis showed a significant reduction in S phase cells,G0/G1 phase cells increased significantly（P〈0.05）, Bcl-2 and Survivin mRNA and gene protein expression levels were significantly lower than other groups. Conclusion The STAT3 protein was down-regulated by RNA interference technology in human hepatocellular carcinoma cell,leading to the reduced expresion of Bcl-2 and Survivin,which induce cell apoptosis.