Both Kdr and Flt1 mediate VEGFA-induced HRMVEC DNA synthesis, migration, and tube formation. (A-C) HRMVECs that were transfected with control, Kdr, or Flt1 siRNA (100 nM) and quiesced were treated with and without VEGFA (40 ng/mL) and either DNA synthesis (A), migration (B), or tube formation (C) was measured. DNA synthesis was measured by [³H]-thymidine incorporation. Cell migration was measured by modified Boyden chamber method. The representative HRMVEC migration and tube formation images are shown in panels B and C, respectively. The bar graphs represent the quantitative analysis of 3 independent experiments. The values are presented as mean ± SD. *P < .01 vs control siRNA; ^†P < .05 vs control siRNA + VEGFA; ^§P < .01 vs control siRNA + VEGFA.