抑制STAT3表达增强多西他赛对人前列腺癌细胞的抗肿瘤作用

Effect of Blocking STAT3 Augments on Resistance of Human Prostate Cancer Cells to Docetaxel

目的:研究抑制信号转导与转录激活因子3(STAT3)的表达增强多西他赛对人前列腺癌细胞DU145的抗肿瘤作用的影响。方法:用慢病毒p FLU-EGFP sh STAT3质粒转染人前列腺癌细胞DU145、构建抑制STAT3的稳定细胞株作为shRNA组,转染空载体作为空白对照(mock)组,采用Western blot方法检测两组人前列腺癌细胞DU145上STAT3和Bcl-2蛋白表达,用Annexin V/PI染色法测定经过多西他赛处理的已抑制STAT3表达的DU145细胞的细胞凋亡;成瘤实验检测采用STAT3抑制与多西他赛(DOX)联合分别注射接种于雄性免疫缺陷小鼠(NSG)的DU145肿瘤和腹腔,观察接种22 d时的小鼠体质量和肿瘤体积。结果:p FLU-EGFP STAT3shRNA载体在沉默STAT3基因表达后,人前列腺癌细胞DU145中抗凋亡基因Bcl-2表达下调,显著降低STAT3和Bcl-2蛋白表达水平;抑制STAT3表达后DU145细胞对多西他赛敏感性显著增加,凋亡细胞显著增多,对多西他赛的敏感性提高了4倍;小鼠成瘤实验表明,接种Dox+shRNA小鼠体质量和肿瘤体积明显下降,抑瘤率增加约80%。结论:抑制前列腺癌DU145细胞中STAT3表达能增强多西他赛抗癌的敏感性,STAT3抑制与多西他赛联合注射接种可增强多西他赛对人前列腺癌的抗癌效果。

Objective： To investigate the effect of STAT3 silencing on the sensitivity of human prostate cancer cells to docetaxel treatment. Methods： Lentiviruses expressing STAT3-specific shRNA were used to infect human prostate cancer DU145 cells to generate a stable cell line as shRNA group,non-specific shRNA as mock group. STAT3 expression and Bcl-2 expression were detected by Western blot. Apoptosis induced by docetaxel was assessed by Annexin V / PI Staining. To determine the effect of STAT3 inhibition on anti-tumor effect of docetaxol in vivo,STAT3 shRNA plasmid and doectaxol were injected into subcutaneous DU145 tumors and perifeneals of NSG immunodeficient male mice,respecti-vely. Tumor weights and tumor volumes were examined at 22 d after implantation. Results：STAT3 expression was significantly silenced. STAT3 silencing resulted in the downregulation of its downstream target,an anti-apoptotic gene Bcl-2. The apoptotic cell death induced by docetaxel was significantly augmented by STAT3 inhibition and apoptotic cells had 4-fold increase compared mock group. Tumor formation assay showed that the tumor weight and tumor volumes in DOX ＋ shRNA group were remarkably decreased when compared to mock ＋ DOX group. The tumor inhibition was about80% in DOX ＋ shRNA group. Conclusions： STAT3 silencing enhances the sensitivity of Du145 cells to docetaxel and antitumor effect of docetaxel.