The Role of αvβ3 in Prostate Cancer Progression

Integrin αvβ3 is involved in varied cell biological activities, including angiogenesis, cell adhesion, and migration on several extracellular matrix components. Although αvβ3 is not typically expressed in epithelial cells, it is expressed in macrophages, activated leukocytes, cytokine-stimulated endothelial cells, osteoclasts, and certain invasive tumors. Interestingly, the adhesion and migration of breast cancer cells on bone matrix are mediated, in part, by αvβ3. Similar to breast cancer cells, prostate cancer cells preferentially metastasize to the bone. The biological events that mediate this metastatic pattern of prostate cancer are not well defined. This review discusses the role αvβ3 plays in prostate cancer progression, with specific emphasis on bone metastasis and on αvβ3 signaling in prostate cancer cells. The data suggest that αvβ3, in part, facilitates prostate cancer metastasis to bone by mediating prostate cancer cell adhesion to and migration on osteopontin and vitronectin, which are common proteins in the bone microenvironment. These biological events require the activation of focal adhesion kinase and the subsequent activation of PI-3 kinase/Akt signaling pathway