慢病毒介导STAT3-shRNA对胃癌细胞化疗敏感性的影响及机制  

Lentiviral-sh RNA-mediated STAT3 silencing enhances chemosensitivity to5-fluorouracil in human gastric cancer cells

作　　者：钟竹[1] 周伟[2] 吴小翎[1] 

机构地区：[1]重庆医科大学附属第二医院消化内科,重庆400010 [2]重庆市肿瘤医院放疗科,重庆400030

出　　处：《重庆医科大学学报》2015年第2期261-265,共5页Journal of Chongqing Medical University

摘　　要：目的:探讨慢病毒介导的sh RNA靶向沉默信号传导及转录激活因子3(signal transducers and activators of transcription 3,STAT3)对人胃癌细胞SGC-7901化疗敏感性的影响及相关机制。方法:构建靶向STAT3基因的sh RNA序列,以慢病毒为载体转染SGC-7901细胞。以real-time PCR及Western blot检测STAT3干扰效果;MTT法分析各组细胞对5-氟尿嘧啶(5-fluorouracil,5-Fu)化疗敏感性的变化;用流式细胞仪比较细胞凋亡率的差异;Western blot检测抗凋亡蛋白B细胞白血病-2(B-cell lymphoma-2,Bcl-2)、髓样细胞白血病-1(myeloid cell leukemia-1,Mcl-1)及survivin的变化。结果:成功构建靶向STAT3基因的慢病毒并转染SGC-7901细胞,有效抑制55%STAT3 m RNA表达和40%STAT3蛋白表达(P<0.05)。STAT3-sh RNA转染后细胞的增殖抑制率及凋亡率均明显升高(P<0.05),抗凋亡蛋白Bcl-2、Mcl-1及survivin蛋白水平明显下降(P<0.05)。结论:慢病毒介导的STAT3-sh RNA可抑制SGC-7901细胞增殖并诱导其凋亡,导致细胞对5-Fu的化疗敏感性增强,相关机制可能是通过抑制STAT3表达从而阻断STAT3信号通路,导致该通路下游的抗凋亡蛋白Bcl-2、Mcl-1、survivin的活性下调。Objective：To investigate the effect and the mechanisms of lentiviral-sh RNA-mediated signal transducers and activators of transcription 3（STAT3）silencing on the chemosensitivity to 5-fluorouracil（5-Fu）,of human gastric cancer cells SGC-7901. Methods：The sh RNA sequences targeting STAT3 was constructed and lentiviral vectors was used to transfect human gastric cancer cells SGC-7901. The interference effect of STAT3-sh RNA was detected by real-time PCR and Western blot. The chemosensitivity to 5-Fu was analyzed by MTT assay and the flow cytometry was used to examine cell apoptotic rate. Western blot was used to compare the expressions of anti-apoptotic proteins Bcl-2,Mcl-1,survivin. Results：Lentiviral vectors containing sh RNA targeting STAT3 gene were successfully established and transfected into SGC-7901 cells.Real-time PCR and Western blot analysis showed that the STAT3-sh RNA significantly inhibited the m RNA expression by 54% and protein expression by 40%（P0.05）. The inhibitory rate of cell proliferation and the apoptotic rate were obviously higher in the cells treated by STAT3-sh RNA（P0.05）. STAT3-sh RNA also induced downregulation of the anti-apoptotic proteins Bcl-2,Mcl-1 and survivin（P0.05）. Conclusion：In summary,STAT3-sh RNA could effectively inhibit the proliferation and accelerate the apoptosis of SGC-7901 cells,leading to the enhancement of their sensitivity to5-Fu. The mechanism may be related with block of STAT3 signaling pathway though inhibiting STAT3 activation,thus decreasing expressions of its downstream anti-apoptotic proteins Bcl-2,Mcl-1 and survivin.

关 键 词：STAT3 慢病毒 化疗敏感性 抗凋亡蛋白 

分 类 号：R735.2[医药卫生—肿瘤] R573[医药卫生—临床医学]