Figure 3

IGF2 protein expression in infantile hemangioma compared with other vascular anomalies. Cryosections of proliferating hemangioma (A and F), involuting hemangioma (B), normal infant skin (C), venous malformation (D), congenital hemangioma (G), and lymphatic malformation (H) were stained with a mouse anti-human IGF2 antibody (all panels except E). Note the presence of endothelial IGF2 expression associated with vascular channels and the lack of IGF2 associated with intralesional arterioles in hemangioma (A, B, and F). Panels E and F are serial sections of a proliferating hemangioma labeled with a rabbit anti-human GLUT1 antibody (E) for comparison to immunostaining observed with a mouse anti-human IGF2 antibody (F). Arrows in panels E and F highlight a GLUT1-positive vessel that appears to be IGF2-negative. (I) Normalized RNA levels for IGF2 (black bars) and KDR (hatched bars) in 5 different isolates of hemangioma-derived endothelial cells (hemEC) were determined by real-time PCR as described in Figure 2. Placental RNA served as a positive control.