Abstract:

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 Tca8113 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 xenografts were measured;immunohistochemical 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 that inhibition of VEGF by RNA interference may serve as a new therapy for drug-resistant tongue cancer.

Key words: RNA interference, Vascular endothelial growth factor, Tongue cancer, Drug-resistance, Cell line