DO MUCINS PROMOTE TUMOR-CELL METASTASIS

Mucins are highly glycosylated proteins that are normally produced by epithelial cells to lubricate and protect the linings of the gastroint estinal, respiratory, and urogenital tracts. Recently, the oligosaccha rides of mucins have been implicated in a number of events that contri bute to tumor progression and metastasis. Mucin associated carbohydrat es serve as receptors for pathogens, reduce homotypic cell-cell and ce ll-substratum interactions, and inhibit the cytotoxic actions of cells of the immune system. Tumor cells, and their mucinous products, imped e the normal trafficking of inflammatory cells while, at the same time , they themselves may use similar mechanisms. These actions can occur at various stages during metastasis.