INHIBITION OF VEGF-C GENE BY siRNA EXPRESSION VECTOR IN HUMAN BREAST CANCER CELL LINE MCF-7

Objective To construct small interfering RNA(siRNA)expression vector and to investigate its inhibitory effect on vascular endothelial growth factor-C(VEGF-C) expression in human breast cancer cell line MCF-7.Methods A pair of hairpin-like oligonucleotide sequences specific for VEGF-C gene were designed and synthesized.The annealed oligonucleotide fragments were subcloned into plasmid pRNAT-U6.1/Neo to construct VEGF-C siRNA expressing vector.Then VEGF-C siRNA expression vectors were confirmed by PCR and sequencing.Transfection of VEGF-C siRNA expressing vector into MCF-7 cells was performed using liposome transfection reagents.VEGF-C mRNA and protein expression were examined by RT-PCR and immunocytochemistry respectively.Results PCR and DNA sequencing showed that siRNA expression vector targeting VEGF-C was successfully constructed.VEGF-C expression in the cells transfected by VEGF-C siRNA expression vectors was inhibited significantly at both mRNA and protein levels.VEGF-C mRNA and protein expression were decreased 61.8% and 78.3% compared with control plasmid respectively(P0.05).Conclusion VEGF-C siRNA expression vector can effectively inhibit the expression of VEGF-C in transfected MCF-7 cells,and provides a basis for breast cancer therapy targeting VEGF-C gene.