The Influence Of Vegf-siRNA On The Growth Of Human Tongue Squamous Cell Carcinoma(Tca8113) Xenografts In Vivo

Objective To investigate the feasibility of gene therapy using vector-based small interfering RNA (siRNA) targeting vascular endothelial growth factor(VEGF) for human tongue squamous cell carcinoma (Tca8113) xenografts in vivo.Methods Palpable human tongue cancer tumors were established on the backs of nude mice by subcutaneous injection of cultured cells (Tca8113). The animals were divided into 4 groups randomly (n=5/group). Two siRNA targeting VEGF constructed in eukaryotic expression vector (PU-VEGF-siRNA1, PU-VEGF-siRNA2) were injected introtumor and peritumor with lipofectamine2000, respectively. Tumors injected vector without siRNA and Non-injected tumors were used as experimental and negative controls. Animals were injected one time every 3 days for total 10 times. Three days after the last injection, the tumors were excised and weighed, the expression of VEGF in xenograft tumors were detected by reverse transcription polymerse chain reaction (RT-PCR) and immunohistochemistry. The cell apoptosis and cell cycle analysis of tumors were detected by TUNEL and Flow cytometry, respectively. Result Compared to the experimental and negative controls, percentage of cells in the G1 phase increased(p<0.05)and the expression of VEGF on both mRNA and protein level were descreased in the PU-VEGF-siRNA2 group(p<0.05), and more apoptosis were induced(p<0.01). But there were not statistically significantly difference of those between PU-VEGF-siRNA1 group and two controls(p>0.05) .Conclusions VEGF- siRNA can reduce VEGF expression in vivo,inhibit tumor growth, and induce apoptosis in Tca8113 cell carcinoma. Different VEGF-siRNA may lead to different effect in vivo.