RNA干扰抑制血管内皮生长因子影响舌癌耐药细胞移植瘤增殖及血管生成

目的研究RNA干扰抑制血管内皮生长因子（VEGF）的表达对舌癌耐药细胞移植瘤增殖及血管生成的影响。方法用顺铂体外连续诱导法诱导舌癌Tca8113细胞系获得耐药细胞，将耐药细胞接种裸鼠皮下建立移植瘤模型，并随机分为空白对照组、空载体组、无关片段组、干扰质粒组。以脂质体法对空载体组、无关片段组、干扰质粒组进行瘤内及瘤周注射转染，RNA干扰抑制VEGF的表达，测量瘤体重量及体积，免疫组化法检测移植瘤PCNA、CD34，比较肿瘤增殖性及微血管参数，原位杂交法检测VEGFmRNA，免疫印迹法检测VEGF蛋白。结果干扰质粒组的瘤体体积、重量、PCNA平均光密度值、微血管参数均小于其他各组（P〈0．05）。干扰质粒组中VEGFmRNA及蛋白表达水平较其他各组明显下降（P〈0．05）。结论通过靶向VEGF的RNA干扰下调VEGF的表达，能抑制人舌癌耐药细胞移植瘤的增殖及血管生成，提示RNA干扰抑制VEGF可能为临床治疗耐药舌痛柽供新途径。

Inhibiting vascular endothelial growth factor by RNA interference affects proliferation and angiogenesis of drug-resistant tongue cancer cell xenografts

Objective To investigate the effect of inhibiting vascular endothelial growth factor（VEGF） by RNA interference on proliferation and angiogenesis of drug - resistant tongue cancer cell xenografts. Methods TcaS113 cells were successively induced in vitro by cisplatin to acquire drug- resistance, and then injected subcutaneously in nude mice to establish xenograft models, which were randomly divided into non - transfected group, mock control group, scrambled sequence group and interference group. The transfection mediated by liposome was done in the latter 3 groups with intratumoral and peritumoral injection for inhibiting VEGF expression. Weight and size of xenogrMts were measured ; immunohistochemieal staining was applied to detect PCNA and CD34 for investigating tumor proliferation and microvessel parameters. In situ hybridization and Western blotting were used to test mRNA and protein of VEGF, respectively. Results The size, weight, mean optical density of PCNA protein and microvessel parameters of xenografts in interference group were less than those in other groups （ P 〈 0.05 ）. The expression of VEGF mRNA and protein in interference group decreased significantly, compared by the other 3 groups （ P 〈 0.05 ）. Conclusion RNA interference targeting VEGF could reduce proliferation and angiogenesis of drug - resistant tongue cancer cell xenografts through inhibiting VEGF expression, suggesting thatinhibition of VEGF by RNA interference may serve as a new therapy for drug - resistant tongue cancer.