Silencing of c-Src abrogates autocrine VEGF-induced MM patient ECs (MMECs) proliferation in vitro, but not the stimuli elicited by PDGF-BB. (A) MMECs were transfected with 50 to 250 nM (lanes 3-5) of siRNA for c-Src (siSrc), 250 nM of a control siRNA (2), or carrier alone (1). After 48 hours, total lysates were analyzed for c-Src and VEGF expression. (B) Proliferation of MMECs transfected with either 250 nM siCTR or siSrc for 24 hours and cultured with or without 10 ng/mL PDGF-BB for an additional 24 hours. Data are means (± SD) of 3 independent experiments (P < .05). (C) Morphologic features of siRNA-transfected MMECs when tested for the effects of PDGF-BB on cell adhesion to fibronectin-coated plates (left panels), motility (middle panels), and angiogenic activity (right panels). (D) Molecular dissection of VEGF expression and activation of signaling molecules in siRNA-transfected MMECs. (E) RT-PCR analysis of proangiogenic genes in serum-starved MGECs and MMECs and after exposure to recombinant PDGF-BB 10 ng/mL alone or with dasatinib 50 nM for 8 hours.