Fig. 2

Tumor-induced angiogenesis blocked by integrin αv antagonists in the chick chorioallantoic membrane (CAM) angiogenesis model (A) M21L human tumor cell fragments lackingαvβ3 or αvβ5 were inoculated on the surface of the CAM of a 10-day-old chick embryos. After 24 hours, embryos received intravenous injections of either control RADfV cyclic peptide (left) or RGDfV cyclic peptide (middle). Adjacent CAM tissue from cyclic peptide is treated CAM is shown on the right. After three days CAMs were excised and analyzed for vascularization. (B) High magnification of the peptide-treated tumors. The left panel is a control peptide-treated CAM and on the right is a cyclic RGD peptide-treated CAM. Note that the αv antagonists acted on the CAM vessels decreasing vascularization of the tumor, since the tumor cells do not express αvβ3 or αvβ5 (67).