沉默STAT3基因对人食管癌EC1细胞裸鼠移植瘤的抑制作用

Inhibitory Effect of Silencing STAT3 Gene by shRNA on Growth of Xenografted Human Esophageal Carcinoma Cell Line EC1 in Nude Mice

目的构建STAT3靶向短发夹RNA(shRNA)质粒,研究其对人食管癌EC1细胞裸鼠皮下移植瘤的作用,探讨其在食管癌基因治疗中的可行性和特异性。方法构建STAT3的siRNA真核表达载体pSUPER-EGFP-STAT3,稳定表达该质粒的细胞为实验组,转染空质粒细胞及未处理细胞为对照组,建立裸鼠荷瘤模型;监测肿瘤生长变化,HE染色观察肿瘤病理学变化,RT-PCR、免疫组化方法检测STAT3mRNA和蛋白变化。结果裸鼠体内实验显示,实验组肿瘤增长受到明显抑制;HE染色显示对照组肿瘤体积大、异形明显;RT-PCR、免疫组化结果表明实验组STAT3mRNA和蛋白表达下调。结论shRNA沉默STAT3基因能抑制人食管癌EC1细胞裸鼠皮下移植瘤的形成,且能在体内有效下调STAT3mRNA和蛋白的表达,为食管癌的基因治疗提供了新的靶点,开辟了新的思路。

Objective Short hairpin RNA（shRNA）plasmid was constructed to investigate its effects on human esophageal carcinoma cell line EC1 in nude mice, and to investigate the feasibility and specificity of gene therapy for esophageal carcinoma. Methods The plasmid pSUPER containing the sequence of shRNA targeting STAT3 was constructed. The EC1 cells transfected with stable pSUPER plasmid were regarded as experimental group and the EC1 cells without being treated by pSUPER plasmid as the control group. The xenografted tumor model was established. Tumor growth was observed, histopathological changes was tested by HE and the mRNA and protein expression of STAT3 were measured by RT-PCR and immunohistochemical staining. Results The tumor growth was obviousibly suppressed;histopathology in the control group showed that the tumor volumes were bigger and high atypic of tumor cells were seen. Futhermore, RT-PCR and immunohistochemical results indicted that STAT3 mRNA and protein expression was reduced in excised tumors. Conclusion Silencing STAT3 gene by shRNA effectively inhibits the tumorigenesis of subcutaneously xenografted ECI cells in nude mice and down-regulated the STAT3 mRNA and protein expression in vivo;it may be a potential therapeutic method to treated human cancer and a possible new approach for esophageal carcinoma gene therapy.