抑制STAT3基因表达对宫颈癌SiHa细胞放射敏感性的影响

Inhibition of STAT3 enhances radiosensitivity of human cervical carcinoma cell line SiHa

目的通过RNA干扰技术抑制宫颈癌SiHa细胞转录活化因子3(signal transduction and activators of transcription3,STAT3)基因的表达,观察细胞放射敏感性的变化。方法构建pSTAT3-siRNA真核表达质粒并转染宫颈癌SiHa细胞,RT-PCR及Western blot法分别检测STAT3基因mRNA及蛋白表达。采用6MV直线加速器分别以不同剂量(0、2、4、6、8 Gy)X线照射细胞,流式细胞仪检测细胞凋亡率,克隆形成实验检测细胞放射敏感性变化。结果与对照组细胞相比,pSTAT3-siRNA转染组细胞STAT3基因mRNA和蛋白水平表达均下降(P<0.05)。细胞经X线照射后,与对照组比较,pSTAT3-siRNA转染组细胞凋亡率升高,SF2值降低(P<0.05)。结论 pSTAT3-siRNA真核表达载体能够抑制宫颈癌SiHa细胞STAT3基因表达,增强其对放射线损伤的敏感性。

Objective To study the effect of silencing STAT3 expression by RNA interference on radiosensitivity of human cervical carcinoma SiHa cells. Methods Vectors containing short hairpin RNA （shRNA） targeting STAT3 （pSTAT3 -siRNA） were constructed and transfected into SiHa cells. The mRNA and protein expressions of STAT3 were determined by RT - PCR and Western blotting, respectively. The different group cells were irradiated by different doses of X - rays （0, 2, 4, 6, and 8 Gy） via the 6MV lin- earity accelerator. The apoptotic rates were detected by flow cytometry and the changes in radiosensitivity were determined by colony formation test. Results The STAT3 expression in pSTAT3 - siRNA group was significantly inhibited, compared with other groups. The apoptotic rate in pSTAT3 - siRNA group was significantly higher than that in other groups. The SF2 values in pSTAT3 - siRNA group were lower than those in other groups. Conclusion The STST3 specific shRNA expression vector effectively suppresses the ex- pression of STAT3 gene in SiHa cells and enhances their radiosensitivity.