Integrins and angiogenesis: unlocking the route to gene therapy

Angiogenesis is defined as the process of vascularization of a tissue, involving the development of new capillary blood vessels. Both the induction and inhibition of this process can have therapeutic benefits in various pathological conditions. Integrins are a structurally elaborate family of adhesion molecules; they participate in a wide range of biological processes, including angiogenesis. Endothelial cells are intimately involved in angiogenesis and are thought to mediate this function partially through the integrins on their cell membrane, which regulate cell-cell and cell-matrix contacts. Extensive research into elucidating the mechanisms involved in the angiogenesis process have led to the discovery of a growing number of genes encoding pro- and anti-angiogenic proteins. A variety of gene therapy approaches have been used to deliver many of these genes to induce or inhibit the angiogenesis process with varying levels of success. This review investigates whether targeting gene therapy vectors to integrin receptors found on endothelial cells is a viable means to improve the efficiency of the gene transfer process.