Down syndrome candidate region 1, a downstream target of VEGF, participates in endothelial cell migration and angiogenesis

Vascular endothelial growth factor (VEGF) is a principal stimulator of angiogenesis. However, the downstream targets of VEGF in endothelial cells (ECs) are not entirely clarified. Survey of downstream targets of VEGF in human ECs identified a number of genes, including Down syndrome candidate region 1 (DSCR1). Here, we confirmed the inducible expression of DSCR1 in ECs by Northern and Western blottings. Moreover, VEGF-stimulated induction of DSCR1 was blocked by anti-VEGF receptor-2 monoclonal antibody (mAb), or the specific calcineurin inhibitors cyclosporin A and FK506. The expression of DSCR1 in ECs of neovessels was further shown by immunohistochemical analysis. We therefore examined whether DSCR1 played any roles in angiogenesis. The specific downregulation of DSCR1 expression by antisense oligonucleotide (AS-ODN) inhibited VEGF-stimulated migration of ECs as well as angiogenesis in vivo. AS-ODN inhibited the spreading of ECs on vitronectin, as well as on the immobilized anti-αvβ3 mAb, but not on anti-αvβ5 mAb. Moreover, AS-ODN inhibited tyrosine phosphorylation of focal adhesion kinase when ECs were plated on a vitronectin-coated dish. Immunoprecipitation followed by Western blotting showed the coimmunoprecipitation of DSCR1 and integrin αvβ3. These results suggest that DSCR1 is involved in angiogenesis by regulating adhesion and migration of ECs via the interaction with integrin αvβ3.