ROLE OF ALPHA(3)BETA(1) AND ALPHA(2)BETA(1) INTEGRINS IN MELANOMA CELL-MIGRATION

Recent findings indicate that variable expression of a integrins may p lay a role in differential melanoma cell motility. Primary melanoma (P M) and metastatic melanoma (MM) cultures, derived from the same patien t, were tested for their beta(1), alpha(2), alpha(3) and alpha(6) inte grin subunit expression and cell migration on type IV collagen (CN IV) or laminin (LN). The MM cell line expressed markedly increased levels of the beta(1), alpha(2) and alpha(3), but not alpha(6) subunit compa red to the PM cell line. The MM cell migration rate was significantly higher than that of the PM cell line on LN- or CN IV-coated substrates . Furthermore, the cell migration rate of both lines was significantly higher (p < 0.001) on these substrates than on the control substrates . The MM and PM cell migration was significantly Inhibited by function -blocking anti-beta(1) and anti-alpha(3) MAbs, but not by the anti-alp ha(6), MAb tested. In contrast, the anti-alpha(2) MAb significantly In hibited MM but not PM cell migration. These data show that the alpha(3 ) subunit plays a significant role In melanoma cell motility on CN IV and LN and that. the alpha(2) subunit has a significant contribution t o the motility of the MM cell line.