Lipopeptide with a RGDK Tetrapeptide Sequence Can Selectively Target Genes to Proangiogenic α5β1 Integrin Receptor and Mouse Tumor Vasculature

Abstract
Integrins, the major class of αβ heterodimeric transmembrane glycoprotein receptors, play crucial roles in mediating tumor angiogenesis. Genetic ablation experiments combined with use of antibodies/peptide ligands for blocking either α5 or β1 integrins have convincingly demonstrated α5β1 integrin to be unquestionably proangiogenic among the 24 known integrin receptors. Herein, we report on a novel RGDK-lipopeptide 1 that targets selectively α5β1 integrin and is capable of targeting genes to mouse tumor vasculatures.