Mucin 1, Tn-glycoform (Tn-MUC1)

Mucin 1 (MUC1) is a high-molecular-weight transmembrane glycoprotein typically expressed on the apical surface of epithelial cells, where it serves a protective and lubricating role [13][17]. In various malignancies, particularly epithelial cancers, MUC1 is overexpressed and undergoes aberrant O-glycosylation, leading to the exposure of truncated carbohydrate antigens such as the Tn antigen (N-acetylgalactosamine linked to Ser/Thr) [2][10]. This Tn-glycoform of MUC1 (Tn-MUC1) acts as a tumor-specific neoantigen because the Tn epitope is normally masked by extended, branched glycan chains in healthy tissues [1][5]. Tn-MUC1 plays a significant role in cancer progression by modulating intracellular signaling pathways like PI3K/AKT and NF-κB, promoting cell invasion, and facilitating immune evasion through interactions with lectins on immune cells [10][19]. Due to its high tumor specificity and prevalence in aggressive cancers like triple-negative breast cancer and pancreatic ductal adenocarcinoma, Tn-MUC1 is a prime target for novel immunotherapies, including chimeric antigen receptor (CAR) T cells, antibody-drug conjugates (ADCs), and monoclonal antibodies [7][12][15]. These therapeutic strategies aim to selectively eliminate cancer cells while minimizing damage to normal tissues that express the heavily glycosylated, non-target form of MUC1 [1][16].

Other names

Tn-MUC1Tumor-associated MUC1tMUC1MUC1-TnCD227 (Tn-form)GalNAc-MUC1

Targeting of tumor-specific glyco-epitopes to induce immune-mediated cell death (e.g., via CAR-T or ADCC) or deliver cytotoxic payloads (via ADCs).