Integrin alpha-3 beta-1 and Integrin alpha-5 beta-1 (α3β1 / α5β1)

Integrin α3β1 and α5β1 are heterodimeric cell surface receptors that play fundamental roles in mediating interactions between cells and the extracellular matrix (ECM). Both receptors share the common β1 subunit (CD29) but utilize distinct α subunits: α3 (CD49c) and α5 (CD49e), respectively. Integrin α3β1 (VLA-3) primarily functions as a receptor for laminins, while α5β1 (VLA-5) is the principal receptor for fibronectin. These integrins are essential for regulating diverse biological processes, including cell adhesion, migration, and intracellular signaling through pathways such as FAK, PI3K/Akt, and MAPK, which govern cell survival and proliferation [1, 7, 11]. In pathological contexts, α3β1 and α5β1 are frequently overexpressed in various solid tumors, including lung, breast, and pancreatic cancers, where they promote tumor invasion, metastasis, and angiogenesis [7, 12, 23]. They are also implicated in the development of fibrotic diseases, bone-related disorders like osteoporosis, and certain infections such as mucormycosis [2, 3, 11]. Therapeutic strategies targeting these integrins include monoclonal antibodies and small molecules designed to block ligand binding and disrupt pathological signaling cascades. While agents like volociximab have reached clinical trials, challenges remain regarding the widespread expression of these receptors in healthy tissues and the potential for compensatory signaling by other integrin family members [1, 6, 12].

Other names

VLA-3 (Very Late Antigen 3)VLA-5 (Very Late Antigen 5)CD49c/CD29CD49e/CD29Fibronectin receptorLaminin receptorGAPB3VCA-2ECMR1

Antagonism of ligand binding (e.g., fibronectin or laminin) and inhibition of downstream signaling pathways, including FAK, PI3K/Akt, and MAPK, to suppress pathological cell migration, tumor invasion, and angiogenesis.