THE LAMININS - A FAMILY OF BASEMENT-MEMBRANE GLYCOPROTEINS IMPORTANT IN CELL-DIFFERENTIATION AND TUMOR-METASTASES

This chapter focuses on the new findings regarding the additional variants, active sites, cellular receptors, signaling events, and the roles of laminin in tumor growth and metastases. Because laminin can regulate so many basic cellular functions in neuronal, epithelial, and tumor cells, a better understanding of its chemistry and role in development and in disease may lead to new strategies for therapeutic/clinical intervention. Laminin is an extracellular glycoprotein found in the matrix, known as the basement membrane that separates epithelial cells from the stromal connective tissue. Laminin is active in cell adhesion, growth, migration, differentiation, and tumor metastases. Various diseases and pathological processes, including tumor growth and metastases, are because of the changes in laminin activity and/or autoantibodies to laminin. The response of the cells is dependent on the cell type and various cell-specific intracellular events are activated. Multiple active sites on laminin and cellular receptors are described in the chapter. Both laminin and the synthetic peptides that define the active sites have important clinical uses. Twelve different cellular receptors are identified, with multiple mechanisms of signal transduction revealed by signaling studies. © 1993, Academic Press Inc. All rights reserved.