Abstract
Mucins are high molecular weight proteins that are highly O-glycosylated. Tumor-produced mucins are detected in tumor tissues and/or the bloodstream of cancer patients, and thus have been used as tumor markers. It has been reported that patients with higher amounts of mucins in their bloodstreams exhibit a lower 5-year survival rate, suggesting that mucins have some biological effect in cancer patients. Since mucins have a variety of sugar chains, it is possible that mucins in the bloodstream interact with some lectins on endothelial cells and/or immune cells. Recent reports suggested that tumor-produced mucins suppress immune function. Here we mainly describe the immunosuppressive effect on B cells through the ligation of mucins with Siglec-2.
