(A) Conditioned medium from IOMM-Lee cells, which were transfected with mock, pSV, puPA or pu2 and subsequently radiated with 10Gy, was added to human microvascular endothelial cells (HMEC-1) pre-seeded on matrigel-coated 96-well plates. After overnight incubation, HMEC-1 were observed for capillary-like network formation and photographed under a light microscope. (B) Angiogenic effect was measured by counting the relative branch-points. Bars represent the means ± SE of three different experiments. *Statistically different compared to control and puPA or pu2 treated groups or IR+control and IR + puPA or IR + pu2 groups (p<0.01).