Mucin 1, tumor-associated Tn-MUC1 glycoform (Tn-MUC1)

Mucin 1 (MUC1) is a high-molecular-weight transmembrane glycoprotein that is normally expressed on the apical surface of epithelial cells, where it serves a protective and lubricating role. In many types of adenocarcinoma, MUC1 is significantly overexpressed and loses its polarized distribution, appearing across the entire cell surface. A defining characteristic of tumor-associated MUC1 is the presence of truncated O-glycans, such as the Tn antigen (GalNAc-Ser/Thr), which results from altered glycosyltransferase activity in cancer cells. This specific glycoform, known as Tn-MUC1, presents a unique glycopeptide neoepitope that is highly tumor-specific and largely absent in healthy tissues. Because of this specificity, Tn-MUC1 is a primary target for next-generation cancer immunotherapies, including chimeric antigen receptor (CAR) T-cells and therapeutic vaccines. These treatments aim to selectively eliminate malignant cells while sparing normal epithelium by targeting the structural differences in the protein's carbohydrate coat.

Other names

MUC1-TnTumor-associated MUC1CD227EpisialinPolymorphic epithelial mucinPEMH23AGPUMEMA

Targeted immunotherapy utilizing monoclonal antibodies, CAR-T cells, or vaccines to recognize the specific Tn-glycopeptide neoepitope, leading to immune-mediated destruction of tumor cells.