Tumor-associated O-glycan (TAOG)

Tumor-associated O-glycans are truncated or abnormally branched carbohydrate structures that arise on the surface of malignant cells due to dysregulated glycosyltransferase activity (Pinho & Reis, 2015, Nature Reviews Cancer). In healthy tissues, O-glycans are typically long and complex, but in cancer, premature termination leads to the exposure of simpler structures such as the Tn (GalNAc-alpha-Ser/Thr), Sialyl-Tn (STn), and Thomsen-Friedenreich (TF) antigens (Munkley & Elliott, 2016, International Journal of Molecular Sciences). These glycans are frequently found on mucins like MUC1 and MUC16, where they contribute to tumor invasion and metastasis by altering cell-cell adhesion and promoting epithelial-mesenchymal transition (Büll et al., 2014, Cancer Research). Furthermore, they facilitate immune evasion by interacting with inhibitory receptors on immune cells, such as Siglecs (Nielsen et al., 2021, Frontiers in Immunology). As these structures are highly enriched on tumor cells and largely absent or masked in normal tissues, they are prime candidates for targeted therapies, including monoclonal antibodies, antibody-drug conjugates, and glycan-specific vaccines (Rodriguez et al., 2018, Trends in Cancer). However, their low immunogenicity and structural heterogeneity remain significant challenges in the development of effective clinical interventions (Zhou & Hakomori, 2023, Glycobiology).

Other names

Tumor-associated carbohydrate antigen (TACA)Tn antigen (GalNAc-alpha-Ser/Thr)Sialyl-Tn antigen (STn)Thomsen-Friedenreich antigen (TF or T antigen)Sialyl-Lewis X (sLeX)Sialyl-Lewis A (sLeA)Truncated O-glycan