125I-Radio labeled Morpholine-Containing Arginine-Glycine-Aspartate (RGD) Ligand of αvβ3 Integrin As a Molecular Imaging Probe for Angiogenesis

In this paper, using a hybrid small-animal Micro SPECT/CT imaging system, we report that a new I-125-Cilengitide-like RGD-cyclopentapeptide, containing D-morpholine-3-carboxylic acid, interacts in vivo with alpha(v)beta(3) integrin expressed by melanoma cells. Images clearly show that the I-125-compound has the capacity to monitor the growth of a melanoma xenograft. Indeed, retention of the labeled ligand in the tumor mass has a good tumor/background ratio, and a significant reduction of its uptake was observed after injection of unlabeled ligand. These results suggest that the use of I-125-labeled morpholine-based RGD-cyclopentapeptides targeting alpha(v)beta(3) positive tumors may play a role in future therapeutic strategies.