Inhibition of angiogenesis by recombinant VEGF receptor fragments

Abstract

Background: Blocking vascular endothelial growth factor receptor (VEGFR) is a successful approach for inhibiting vascular endothelial growth factor (VEGF) signaling. Small molecules impairing the interaction of VEGF with VEGF receptors have been synthesized and evaluated in this research. Methods: In this study, we amplified and cloned the cDNA of VEGFR fragments. After expression of the fragments in Escherichia coli (E. coli), they were purified by immobilized metal affinity chromatography (IMAC). The biological activity of recombinant KDR fragments was evaluated by human umbilical vein endothelial cells (HUVEC) proliferation assay. Results: The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PSGE) and immune-blotting results confirmed the production and purification of recombinant VEGFR fragments. The purified VEGFR2-III domain, VEGFR2-II-III domains, and VEGFR1-II domain showed 24%, 36%, and 27% inhibition effect in HUVEC proliferation assay, respectively. The recombinant VEGFR2-II-III domains strongly inhibited formation of capillary-like structures (CLS). Conclusions: The produced recombinant proteins will serve as small soluble molecules with an inhibitory effect against VEGF in anti-angiogenesis researches.