Anti-angiogenesis and anticancer effects of a plasmid expressing both ENDO-VEGI151 and small interfering RNA against survivin.

We have previously reported that the overexpression of the endostatin-vascular endothelial cell growth inhibitor (VEGI) fusion protein inhibits angiogenesis and achieves a strong anticancer effect. In this study, we constructed the dual-function expression plasmid pCDNA3.1-ENDO-VEGI151/survivin-small interfering RNA (siRNA) (pEV/si-survivin), and evaluated the anti-angiogenesis and anticancer effects of this plasmid. Efficient siRNA sequences against survivin were identified; and the pEV/si-survivin expression vector was constructed and transfected into MDA-MB-231 cells and human umbilical vein endothelial cells (HUVECs). The expression levels of ENDO-VEGI151 and survivin were detected by RT-PCR and Western blotting analysis. MTT assay was used to detect the proliferation of cancer cell lines. Flow cytometry was used to detect cell cycle states and apoptosis. The expression of both ENDO-VEGI151 and survivin-siRNA were detected in MDA-MB-231 and HUEVC cells transfected with pEV/si-survivin. The expression of survivin was reduced in cells transfected with pEV/si-survivin. Furthermore, pEV/si-survivin inhibited proliferation and promoted apoptosis in MDA-MB-231 and HUEVC cells. It also caused cell cycle arrest in both cell lines. In conclusion, the dual-function expression plasmid pEV/si-survivin is involved in inhibition of angiogenesis and promoting tumor cell apoptosis in vitro. Therefore, it is also expected to improve the treatment of tumors by exerting synergistic effects in vivo.