Coexpression of vascular endothelial growth factor and its receptor KDR ongastric adenocarcinoma MGC803 cell line and stimulation of exogenous VEGF165 to MGC803 cells

Vascular endothelial growth factor (VEGF), also known as vascular permeabil ity factor (VPF), is an angiogenic factor playing an important role in tumo r growth. VEGF/VPF interacts with endothelial cells by way of two high-affi nity receptor tyrosine kinases: flt-1 and KDR. The vast majority of publish ed studies have described expression of the VPF/VEGF receptors specifically in endothelial cells. To elucidate the further function of VEGF in solid t umor development, the coexpression of VEGF and KDR in gastric adenocarcinom a MGC803 cell lines was shown by reverse transcription polymerase chain rea ction (RT-PCR). The MGC803 tumor cells could also be strongly immunostained for KDR by immunocytochemistry. It was further demonstrated that exogenous VEGF(165) can stimulate the MGC803 cell growth in both dose-dependent and time-dependent manners by H-3-thymidine incorporation. Furthermore, anti-VE GF(165) monoclonal antibody and anti-KDR monoclonal antibody could dose-dep endently block the VEGF(165)-induced cell growth. These results provided ne w evidence that VEGF could cause autocrine stimulation to the proliferation of gastric adenocarcinoma cells.