Effects of autocrine vascular endothelial growth factor (VEGF) in non-small cell lung cancer cell line A549

Abstract

It is reported that the autocrine loop of the vascular endothelial growth factor (VEGF) is crucial for the survival and proliferation of non-small cell lung cancer (NSCLC) tumors. In this study we aimed to systematically investigate the role of autocrine vascular VEGF in NSCLC cell line A549 through inhibition of endogenous VEGF. A549 cells were transfected with florescence-labeled VEGF oligodeoxynucleotide with lipofectamine. For the experimental group, cells were transfected with VEGF anti-sense oligodeoxynucleotide (ASODN), sense oligodeoxynucleotide (SODN) and mutant oligodeoxynuleotide (MODN) respectively. For the control group cells were mock transfected with lipofectamine or culture medium. At indicated time point after transfection, the expression levels of VEGF mRNA and protein in A549 cells were analyzed by RT-PCR and ELISA respectively. Cell viability was measured by the MTT assay. Cell cycle distribution was detected by flow cytometry. As revealed by RT-PCR assay, the mRNA level of VEGF in cells transfected with ASDON was significantly lower than the other four groups (P < 0.05) at 24 and 48 h after transfection. ELISA assay yielded similar result with significantly decreased level of VEGF protein expression (P < 0.05). The survival fraction of A549 cells transfected with ASDON was significantly lower than the other four groups (P < 0.05) at 24 h after transfection. Also the percentage of G2 phase cells of ASODN group was significantly lower than other four groups. Our data indicate that VEGF expression is efficiently inhibited in A549 cells by ASODN transfection and this inhibition leads to inhibited cell growth and impaired cell cycle distribution.