探讨靶向VEGF的shRNA与微管蛋白抑制剂联合给药对人前列腺癌DU145的抗肿瘤增效作用。构建针对VEGF的shRNA干扰表达载体pCSH1-VEGF;采用RT-PCR、Western blotting方法检测pCSH1-VEGF对DU145细胞VEGF转录和表达的影响;Matrige1细胞侵袭检测pCSH1-VEGF对DU145运动迁移的影响;MTT法检测瞬时转染pCSH1-VEGF后DU145细胞对紫杉醇、长春新碱的敏感性变化;以裸鼠移植性前列腺癌DU145为模型,观察pCSH1-VEGF与紫杉醇联合给药的体内抗肿瘤作用。实验结果显示,干扰载体pCSH1-VEGF可以显著降低VEGF的转录和表达水平。pCSH1-VEGF可以显著降低DU145细胞对人工基底膜的侵袭能力,抑制率为56.1%。瞬时转染pCSH1-VEGF后,细胞对紫杉醇、长春新碱的敏感性显著增强,IC50值分别降低77.3%和92.6%。动物实验研究表明,紫杉醇10mg·kg^-1对前列腺癌DU145的抑瘤率为48.8%,pCSH1-VEGF单独给药的抑瘤率为56.2%,pCSH1-VEGF与紫杉醇联合给药的抑瘤率为81.8%,两药相互作用指数CDI为0.82,有明显的增效作用。研究结果提示,pCSH1-VEGF可以显著增强微管蛋白抑制剂对前列腺癌的治疗作用。
In this study, the antitumor activities of VEGF shRNA and tubulin inhibitors on human prostate cancer DU145 cells was investigated, and shRNA transient expression plasmid pCSH1-VEGF targeting VEGF mRNA was constructed. The silence efficiency of pCSH1-VEGF was detected by RT-PCR assay, Western blotting, and Matrigel invasion assay. The sensitivity change of DU145 cells to Taxol and vincristine (VCR) was measured by MTT assay. To detect the effects of pCSH1-VEGF and Taxol in vivo, nude mice model of DU145 xenograft tumor was established by subcutaneous inoculation. The results showed that transcription and expression of VEGF were knocked by pCSH1-VEGF in DU145 cells. Matrigel invasion assay results showed that pCSH1-VEGF significantly reduced the migration of DU145 cells with inhibitory rate of 56.1%. Furthermore, pCSH1-VEGF enhanced the sensitivity of DU145 cells to Taxol and vincristine, and the values of ICs0 decreased by 77.3% and 92.6%, respectively. In vivo experiment showed that Taxol, pCSH1-VEGF, combination of pCSH1-VEGF and Taxol inhibited tumor growth by the rates of 48.8%, 56.2% and 81.8%, respectively. The coefficient of drug interaction (CDI) of pCSH1-VEGF and Taxol was 0.82. The data suggested that VEGF shRNA could significantly enhance the sensitivity of human prostate cancer to tubulin inhibitors.