Objective: To investigate the anti-angiogenesis activity of the extracellular domain of vascular endothelial growth factor (VEGF) receptor KDR.
Methods: The eukaryotic expression plasmid pcDNA3.1/KDR(n7) of the extracellular domain of KDR was transfected into the human bladder carcinoma EJ cells by lipofactamin technology. Cellular clone that stably expressed the target protein was obtained by G418 screening. The cellular clone that expressed the target protein specifically combined with VEGF was obtained by solid-phase binding assay. The positive cellular clone was identified by RT-PCR.
Results: The rKDR(n7) expressed by EJ cells can inhibit the angiogenesis in egg CAM. The EJ cell strain significantly inhibits the growth and angiogenesis of human bladder carcinoma in nude rat. The microvascular density in the experimental group was 12 +/- 4, significantly lower than that in hte negative control group (62 +/- 11).
Conclusion: Inhibition of the VEGF/KDR signal transmission channel can inhibit the angiogenesis in tumor, thus delaying its growth.