Osteopontin modulates prostate carcinoma invasive capacity through RGD-dependent upregulation of plasminogen activators

Osteopontin, a non-collageneous bone matrix protein, is produced in several human tumors but its role in cancer progression has been only partially elucidated. In this study we investigated the potential role of osteopontin in the malignancy of prostate cancer cells. Chemotaxis and chemoinvasion analyses revealed a dose-dependent increase in PC3 cell movement induced by osteopontin and a strict dependence of cell invasion on alpha(v)beta(3) integrin function. The pattern of protease expression was modified by osteopontin and was characterized by an upregulation of plasminogen activators. Our findings suggest that osteopontin may confer selective malignant potential to prostate cancer cells through the enhancement of their invasive and proteolytic capability.