Inhibition Of Expression Of VEGF Gene In Human Breast Cancer MCF-7 Cells By SiRNA

Objective: This study was to evaluate the effect of RNA interference-mediated vascular endothelial growth factor (VEGF) gene silencing on proliferation and apoptosis of human breast cancer MCF-7 cells.Methods: Small interfering RNA (siRNA) targeting VEGF gene was designed and DNA template was synthesized, then siRNA was obtained by in vitro transcription. The non-transfected cells, cells treated with Lipofectimine and cells treated with siRNAscR were taken as controls.After ds-siRNA were transfected into MCF-7 cells with Lipofectamine, MTT colorimetry was used to detect the proliferation of MCF-7 cells. By Hoechst33258 staining the apoptosis of MCF-7 cells was tested. Flow cytometry was used to detect the change of cell cycle. The expression of VEGF mRNA and bcl-2 mRNA were analyzed by RT-PCR and the expression of VEGF protein was analyzed by immunohistochemical technology.Results: The siRNA targeting human VEGF effectively inhibited the secretion of VEGF in MCF-7, whereas the control scramble siRNA showed no effects.MTT assay showed that siRNA ₁ and siRNA₂ markedly inhibited the proliferation of breast cancer cells MCF-7, while the control scramble siRNA showed no effects to MCF-7 cells. Hoechst33258 staining showed siRNA induced cell apoptosis and the apoptositic bodies also appeared. It affected the distribution of cell cycle, increased cell population in G₀/G₁ phase and decreased it in S phase, the expression of VEGF mRNA and bcl-2 mRNA was significantly inhibited in MCF-7 cells. The immunohistochemical technology showed the VEGF protein of the MCF-7 cells transfected with siRNA ₁ and siRNA₂ for 48 hours were significantly lower than the untransfected cells, while the control scramble siRNA showed no effects to MCF-7 cells.Conclusions: MCF-7 cells by transfected siRNA could reduce VEGF gene expression,inhibit proliferation and induce apoptosis of MCF-7 cells.VEGF gene was effective site in anti-vasculogenesis of breast cancer. The siRNAs which we designed and synthesized with T7RiboMAX? Express RNAi System were high-quality and could be transfected to MCF-7 cells. siRNA molecule may create a more promising and efficacious siRNA-based gene drugs against tumors.