In this study, we report the role of integrin alpha(5) in promoting melanoma metastasis. The alpha(5) expression was remarkably elevated in highly metastatic B16F10 melanoma cells compared to lowly metastatic B16F1 cells, whereas no significant changes were detected in those of integrin alpha(4), alpha(v), and beta(1) subunits. Neutralization of alpha 5 with anti-alpha(5) antibody significantly suppressed the potential of B16F10 cells for pulmonary metastasis in mice and inhibited cell adhesion or spreading to fibronectin in vitro. Furthermore, loss of the interaction between alpha(5) and fibronectin diminished cell survival and induced apoptosis in B16F10 cells. Above results provide clear evidence that integrin alpha(5) is positively correlated with melanoma metastasis and might be an anti-melanoma target. (c) 2005 Elsevier Inc. All rights reserved.