Down-regulated expression of vascular endothelial growth factor-C inhibits the invasiveness of MCF-7 breast cancer cells

Abstract

Objective To study whether down- regulation of vascular endothelial growth factor (VEGF)-C expression with RNA interference can inhibit the invasiveness of human MCF-7 breast cancer cells. Methods Recombinant vector (pSIREN-VEGF-C) was transfected into human breast cancer cell MCF -7 by liposome and positive transfected cell clones were screened with puromycin. Expression of VEGF-C in MCF- 7 cells after gene transfer was detected by real- time quantitative PCR and Western blot assay respectively. Invasiveness of transfected ceils were analyzed by Transwell filter. Expressions of MMP-2 and -9 mRNA were detected by semi-quantitative RT-PCR in transfected cells.Results The expressions of VEGF-C mRNA and proteins were reduced markedly compared with control group after transfection and the inhibition rate was 95% and 100% respectively (P<0.05).The invasiveness as reflected by number of Transwell filter penetrating MCF-7 cells declined evidently in those transfected by pSIREN-VEGF-C as compared to those without transfection (P<0.05).The expressions of MMP-2 and -9 mRNA in transfected cells were down-regulated significantly compared with control group and the inhibition rate was 55% and 75% respectively (P<0.05).Conclusion Down-regulating the expression of VEGF-C may significantly inhibit the invasiveness of human MCF-7 breast cancer cells. Key words: Breast neoplasms; Vascular endothelial growth factor C; Matrix metalloproteinases; RNA interference; Invasion