[Functions of mucin molecules in gastrointestinal cancer]

Studies about the function of mucin molecules as surface molecule of adenocarcinoma of gastrointestinal tract had just started, and several important function of mucins had been revealed. In the process of the malignant transformation, class of the expressed mucin core protein and content of glycochain of mucin molecule was changed. Changes of glycoprotein of mucin molecule during transformation affect immunogenesity, tumorigenesity, metastatic ability and sensitivity for anti-cancer drugs. Glycosylated mucin acts important roles during metastatic sequence and prognosis of the gastrointestinal cancer was collerated with expression of immatured mucin of cancer cells. A type of mucin with immature type of glycochain, MUC1, had a protective function for cytotoxicity, e.g. natural killer cell and cytotoxic T-cell, and deglycosilation of MUC1 sensitize cancer cells for cytotoxicity. And MUC1 reduce sensitivity for anti-cancer drugs and MUC1 was glycosilated during process to get resistance for anti-cancer drug. The functions of mucin molecules is not fully revealed, but further studies will indicate importance of mucin molecules in tumor progression.