Defining the Role of Integrin αvβ6 in Cancer

Integrins are a large family of heterodimeric transmembrane receptors that mediate cell-substratum adhesion. alpha v beta 6 is an epithelial-specific integrin that is a receptor for the extracellular matrix (ECM) proteins fibronectin, vitronectin, tenascin and the latency associated peptide (LAP) of TGF-beta. Integrin alpha v beta 6 is not expressed in healthy adult epithelia but is upregulated during wound healing and in cancer. alpha v beta 6 has been shown to modulate invasion, inhibit apoptosis, regulate the expression of matrix metalloproteases (MMPs) and activate TGF-beta 1. There is increasing evidence, primarily from in vitro studies, that suggest that alpha v beta 6 may actually promote carcinoma progression. In this review we summarize what has been learnt in the past few years about the role of alpha v beta 6 in cancer progression.