Pharmacology of the cell/matrix form of adhesion.

Cell adhesions are heterogeneous processes including two main forms, CAM and cell/matrix forms. Both these forms induce the interaction among cells and with the extracellular matrix, and the generation of intracellular signals. The signaling of the two adhesion forms include, at the cell surface, involvement of distinct integrins, necessary for intracellular cascade activation. I will focus on the cell/integrin form based on two specific integrins, α5β1 (the most important) and αvβ3, activated by the preferential binding of fibronectin, a unique extracellular matrix protein. Such binding induces local assembly of stratified adhesion complexes containing protein kinases, that trigger the intracellular signaling cascades (Akt, ERK and others); proteins that sustain mechanical processes; and proteins associated with the cytoskeleton. In view of its role in several diseases, from cancers to the eye macular-degeneration; from brain neurodegeneration to fibroses, the pharmacological interest for the cell/integrin adhesion has grown, and presumably will further grow in the near future. The agents identified and developed for therapy include antibodies, many peptides and chemical drugs against α5β1 integrin; drugs against fibronectin and metalloproteinases 2/9, responsible of the latter enzyme proteolysis; anti-kinase and anti-cascade drugs, some of which targeted to the activation of transcription factors and/or their transfer to the nucleus, with repression or activation of gene expression. A new perspective, based on the investigation of both animal models and human patients, includes factors active on the cell/matrix and CAM adhesions, considered separately or coordinately in distinct therapeutic approaches, integrated or not with classical chemotherapic treatments.