MUC1

Mucin 1 (MUC1), also known as CD227, is a highly glycosylated transmembrane protein that widely exists in almost all secretory epithelial cells of the breast, prostate, digestive tract, respiratory tract, and reproductive tract. MUC1 is a key member of the mucosal defense system, serving as a lubricant, moisturizer, and physical barrier, which participates in epithelial cell proliferation and repairing. Some research has found that MUC1 is abnormally high expressed in breast cancer, cervical cancer, gastric cancer, colorectal cancer, lung cancer and other adenocarcinoma tissues, so it has become a popular tumor marker in clinical practice. In addition, the abnormal glycosylation of MUC1 occurs in tumor tissues, leading to a decrease in the adhesion between tumor cells and immune cells. It also inhibits the expression of tumor suppressors and induces epithelial-mesenchymal transition (EMT) through multiple signaling pathways, thereby promoting tumor infiltration and metastasis. Therefore, MUC1 plays an important guiding role in the prognosis evaluation of patients, and it has become a research highlight in tumor immunotherapy.