VEGF signals through MEK/ERK and AKT to mis-regulate centrosome duplication in endothelial cells. HUVECs were serum starved, then incubated with low or high VEGF. (A) HUVECs treated for 5 minutes without inhibitor or with U0126 (MEKI) or 1L-6-hydroxymethyl-chiro-inositol 2-(R)-O-methyl-3-O-oxtadecylcarbonate (AKTI) were lysed, hybridized to anti-P-ERK, and normalized to total ERK2. (B) HUVECs treated with low or high VEGF for 1 hour were lysed, hybridized to anti-P-AKT, and normalized to total AKT. (C) HUVECs treated with indicated levels of VEGF for 12 hours without inhibitors or with MEKI or AKTI were lysed, hybridized to anticyclin E, and normalized to actin. (D) HUVECs treated with indicated levels of VEGF for 96 hours without inhibitors or with MEKI or AKTI were fixed, stained for γ-tubulin and DRAQ5, and centrosome numbers were counted (low VEGF, n = 1036; high VEGF, n = 1369; high VEGF + MEKI, n = 1152; high VEGF + AKTI, n = 586). All experiments were performed at least 3 times. *P < .05 vs low VEGF. **P < .001 vs low VEGF. ***P < .0001 vs low VEGF. #P < .05 vs high VEGF. ##P < .001 vs high VEGF.