Fig 1: Expression of PDGF signaling axis in hemangioma-derived CD133+ cells. (a) Expression of PDGFRs in hemSCs and bm-MPCs (data normalized to 18 S rRNA and presented as relative to bm-MPCs; two different hemSC preparations run in triplicates were averaged). (b) Expression of PDGF transcripts in hemSCs (data presented as in (a); *P<0.05 compared with bm-MPCs; right panel shows the expression of PDGF-A, PDGF-C, and PDGF-D at a lower scale). (c) PDGF-BB levels in media from cells cultured for 48 h in EBM2/20%FBS (with growth factors) (*P<0.05 compared with bm-MPCs). (d) PDGF-BB levels in cell lysates determined by ELISA (*P<0.05 compared with bm-MPCs). (e) Levels of phosphorylated PDGFR-α and -β in hemSCs with or without exogenous PDGF-BB stimulation (cells were stimulated with 10 ng/ml PDGF-BB; *P<0.05 compared with unstimulated cells). (f) Schematic illustration of the hypothesized PDGF polypeptides and the corresponding receptors on hemangioma stem cell surface