Laminin-5 in the progression of carcinomas

The basement membrane (BM) separates epithelia[ elements from the surroundi ng stroma, BM is dynamic in regulation of epithelial cells differentiation as well as their organization into 3-dimensional tissues. In these function s, among the molecules of the BM, laminins are especially dynamic. Laminins are distributed in a spatially and temporally regulated manner in various epithelia] tissues. Various changes in the laminin distribution accompany t he malignant transformation of epithelia. The role of the BM and laminins i n the progression of carcinomas is not well understood. The BM has been sug gested to act as a mechanical barrier against carcinoma cell invasion. BM l aminins may play an active role in regulating the migration and proliferati on of the carcinoma cells. Laminin isoform laminin-5 expression is typical for some invasive carcinomas and it may act as a ligand for invading carcin oma cells. Neoexpression of laminin-5 has also been associated to prolifera tive activity of the carcinoma cells. Integrins alpha (3)beta (1) and alpha (6)beta (4) are probable cell surface receptors acting with laminin-5 in t he regulation of carcoma cell invasion and proliferation. (C) 2001 Wiley-Li ss, Inc.