RGD-binding integrin receptor (RGD-integrin)

RGD-binding integrin receptors are a specialized subfamily of eight heterodimeric transmembrane proteins (Integrin alpha-V beta-1, alpha-V beta-3, alpha-V beta-5, alpha-V beta-6, alpha-V beta-8, alpha-5 beta-1, alpha-8 beta-1, and alpha-IIb beta-3) that specifically recognize the Arginine-Glycine-Aspartic acid (RGD) tripeptide motif found in extracellular matrix (ECM) proteins like fibronectin, vitronectin, and fibrinogen [1, 10, 11]. These receptors act as critical mechanical and chemical links between the ECM and the intracellular cytoskeleton, mediating bidirectional signaling ("inside-out" and "outside-in") that regulates cell adhesion, migration, proliferation, and survival [2, 10, 15]. In pathological states, RGD-binding integrins are frequently upregulated; for instance, alpha-V beta-3 and alpha-5 beta-1 are key drivers of tumor angiogenesis and metastasis, while alpha-V beta-6 and alpha-V beta-8 are involved in the activation of latent TGF-beta, contributing to tissue fibrosis and immune evasion in cancer [2, 13, 15]. Therapeutically, this subfamily has been targeted with various modalities, including monoclonal antibodies, cyclic peptides (e.g., Cilengitide), and small molecule peptidomimetics [3, 4, 10]. While alpha-IIb beta-3 antagonists like abciximab and eptifibatide are successfully used as anti-thrombotic agents, many oncology candidates have faced challenges in clinical trials due to tumor heterogeneity and complex compensatory mechanisms [3, 11, 14]. Beyond direct inhibition, RGD-like ligands are extensively utilized as "homing" motifs for the targeted delivery of nanoparticles, chemotherapeutics, and radiopharmaceuticals to integrin-overexpressing tissues, particularly in the context of molecular imaging and precision oncology [3, 4, 12].

Other names

RGD-recognizing integrinRGD-binding integrin subfamilyIntegrin receptor (RGD-binding)RGD-binding integrin

Competitive inhibition of ligand binding to the RGD-binding pocket, disrupting cell-extracellular matrix adhesion and bidirectional signaling pathways.