Carbohydrate antigens on cancer-associated mucin-like molecules.

Mucins are large molecular weight glycoproteins characterized by carbohydrate sugars attached via 'O-glycosidic' linkages to serine or threonine. Mucins are synthesized by a variety of epithelial tissues as membrane-bound or secreted proteins, encoded by several distinct mucin genes. Numerous alterations of mucin-associated carbohydrates can be detected in neoplastic epithelial tissues and on circulating mucins in patients with adenocarcinomas. The expression of various sialyosylated-carbohydrate epitopes may correlate with poor prognosis and enhanced metastatic disease in colorectal adenocarcinomas. Mucin-associated carbohydrate and peptide antigens are currently being investigated for their role in cancer diagnosis, monitoring for progression or metastases, immunotherapy and immunosuppression.