Inhibitory effect of combined transfection of antisense oligonucleotides of VEGF-C and COX-2 on the expression of VEGF-C in breast carcinoma cell line

Objective:To investigate the effect of combined transfection of antisense oligonucleotides (ASODNs) of vascular endothelial growth factor-C (VEGF-C) and cyclooxygenase-2 (COX-2) by cationic liposome (LIP) on the expression of VEGF-C in breast carcinoma MDA-MB-231 cells. Methods:Cytotoxicity of ASODNs on MDA-MB-231 cells was measured by MTT assay and the optimal concentration for transfection was determined. The transcription of VEGF-C in breast carcinoma cells was detected by RT-PCR. The protein expression of VEGF-C was detected by immunohistochemical staining and confocal laser scanning microscopy in MDA-MB-231 cells after co-transfection of VEGF-C and COX-2 ASODN. Results:No cytotoxic effect was found when ASODNs/LIP was transfected at 0.2 mmol/L+2.5 mL/L. The inhibitory ratio on VEGF-C mRNA transcription was 70.37% in the combined transfection group, which was significantly higher than VEGF-C transfection group and COX-2 transfection group (48.15% and 42.21%, P0.01). The protein expression of VEGF-C was significantly lower in the combined transfection group than that in only VEGF-C or COX-2 transfection group (P0.01). Conclusion: Combined transfection of VEGF-C and COX-2 ASODN markedly decreases the expressions of VEGF-C at mRNA and protein levels in MDA-MB-231 cells. COX-2 maybe involved in the induction of VEGF-C expression in breast cancer.