CB1 inactivation inhibits migration and capillary-like tube formation of endothelial cells. (A) HUVECs transfected with either control siRNA or CB1-siRNA for 24 hours or pretreated or not with CB1 antagonist (0.3μM, 30 minutes) were assayed in the Transwell migration assay using bFGF as chemoattractant (10 ng/mL, 4 hours). The graph reports the mean ± SD of 3 independent experiments in triplicates expressed as percentage of migrated cells. Basal migration in the absence of bFGF (chemokinesis) was subtracted from each point (ANOVA, **P < .01 vs control). (B) HUVECs transfected with either control siRNA or CB1-siRNA for 24 hours or pretreated or not with CB1 antagonist (0.3μM, 30 minutes) were stimulated or not with bFGF (10 ng/mL, 6 hours). Magnification, ×10. Histograms represent the number of intersections for control (white bars) and CB1 antagonist-treatment (black bars; mean ± SD from 4 independent experiments; ANOVA, **P < .01, ***P < .001).