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 gastrointestinal, respiratory, and urogenital tracts. Recently, the oligosaccharides of mucins have been implicated in a number of events that contribute to tumor progression and metastasis. Mucin associated carbohydrates serve as receptors for pathogens, reduce homotypic cell-cell and cell-substratum interactions, and inhibit the cytotoxic actions of cells of the immune system. Tumor cells, and their mucinous products, impede 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.