Galectin-1: Secretion and modulation of cell interactions with laminin

Galectin-1 is a homodimeric lectin which is expressed at high levels in skeletal and smooth muscle, peripheral nerves, and some tumor cells. It has particular affinity for polylactosamine oligosaccharides. This review discusses the evidence that galectin-1 is secreted by unorthodox mechanisms and then binds to polylactosamine chains on laminin in the extracellular matrix and integrins, LAMPs, or lactosamine-containing glycolipids on cell surfaces. Depending on which matrix and cell surface receptors are expressed, galectin-1 can either promote or inhibit cell adhesion, migration, and neurite elongation. In this way galectin-1 is suspected to participate in regulating changes in cell interactions during normal development and tumor metastasis.