The investigation of gene silencing efficiency in breast cancer and vector design containing shRNA specific to two different genes (VEGF-A and VEGFR-2)

Aim: The growth and metastasis of breast tumor is dependent to angiogenesis. Suppression of a single angiogenic factor can be insufficient to inhibit angiogenesis. The design of vectors encoding several shRNAs is an important strategy for RNAi technology. The vector that targets different genes to produce more efficient protein expression suppression. In this study, a single RNAi-based vector modification containing targeted shRNAs to VEGF-A and VEGFR-2 genes, which play an important role in angiogenesis, aimed to increase the RNAi effect in cells and to improve therapeutic efficacy in breast cancer. Material and Method: In our study, VEGF-A and VEGFR-2 specific shRNA sequences were designed and both shRNA sequences were cloned into the vector in one and two steps and control studies were performed. In addition, to clonning of both sequences into one vector and of each sequence separately into the vector was used same method. The gene silencing activities of single and dual cloned plasmids were examined by ELISA method in MCF-7 and MDA-MB-231 cells. Results: In our study, gene silencing efficiency was found to be higher in vectors with dual cloning than vectors with single cloning. The protein expression in breast cancer cells was significantly suppressed by the use of silencing vectors cloning VEGF-A and VEGFR-2 specific sequences that play an active role in angiogenesis. Conclusion: As a conclusion, it can be suggested that RNAi technology can be obtain promising results in treatment of breast cancer by together silence of different angiogenic factors and their associated receptors.