GALECTIN-1 MODULATES HUMAN-MELANOMA CELL-ADHESION TO LAMININ

Galectins constitute a gene family of beta-galactoside-specific lectin s that show high homology in their carbohydrate-binding site. They hav e been postulated to be involved in many biological events, but their specific functions are not yet well defined. Galectin-1 is a laminin b inding protein that recognizes poly N-acetyllactosamine chains on this major basement membrane glycoprotein. In this study, we analyzed the possibility that galectin-1 could modulate interactions between human melanoma cells and laminin. We demonstrated that A375 and A2058 cell l ines express galectin-1 both intracellularly and on the cell surface. in an in vitro assay, recombinant galectin-1 increased melanoma cell a ttachment to laminin in a dose-dependent manner. This effect was aboli shed by lactose. Anti-galectin-1 inhibited adhesion of melanoma cells to laminin in a However, neither galectin-1 nor anti-galectin-1 antibo dy affected melanoma cell spreading on laminin in vitro. These data in dicate that galectin-1 might participate in melanoma cell adhesion to laminin and therefore could be a modulator of invasion and metastasis. (C) 1995 Academic Press, Inc.