Inhibition of endothelial cell proliferation, migration, and capillary-like tubule formation by IDR-E804.(A) HUVECs were plated in 96-well plates, allowed to attach overnight, and then cultured for 24 h with vehicle or the indicated concentration of IDR-E804. The proliferation was measured as described in the Materials and Methods section. (B) For cell migration, a monolayer of inactivated HUVECs was scratched by a 0.1-mL pipette tip, and fresh medium containing vehicle or IDR-E804 was then added. After 24 h, migration of HUVECs was quantified. Original magnification, ×40. (C) For capillary-like tubule formation, HUVECs (4 × 104/well) were seeded onto Matrigel-coated 24-well plates and incubated with vehicle or IDR-E804 at 37°C for 16 h. Endothelial tubules were then photographed and quantitated. Original magnification, ×40. The results shown are the means ± S.E. of four independent experiments conducted in triplicate. *P < 0.05, **P < 0.01, ***P < 0.001 versus VEGF-treated HUVECs.