Mucin and Cancer

Abstract

Mucin family comprises secretory and membrane-bound mucins. Mucins contain a variety of O-linked oligosaccharides that comprise more than 50 % of the mucin molecule by weight. Several mucin-type O-glycans have been revealed to be cancer-associated carbohydrate antigens. They are useful for diagnosis and monitoring of cancer progression. Several secretory mucins form a gel to protect and lubricate luminal epithelial surfaces. In addition to this protective function, many evidences have been obtained that several membrane-bound mucins are involved in signaling events that contribute to the progression of cancer. MUC1 is aberrantly over expressed in various malignant tumors, and its expression level is correlated with poor prognosis. MUC1 engages in signal transduction by interacting with receptors for growth and differentiation factors, which contributes growth and survival of cancer cells. The oncogenic effects of MUC1 are revealed to occur through the interaction of MUC1-C-terminal domain with various signaling molecules and subsequent transportation of the resultant complexes to the nucleus.