N-acetylgalactosamine-terminating glycan (GalNAc-glycan)

N-acetylgalactosamine (GalNAc)-terminating glycans are carbohydrate structures characterized by a terminal GalNAc residue, most notably represented by the Tn antigen (GalNAc-alpha-O-Serine/Threonine) (Springer, 1984). In normal physiology, these residues are typically intermediate structures that are rapidly elongated by glycosyltransferases into complex O-glycans; however, in many adenocarcinomas, this process is disrupted, leading to the high-density expression of truncated GalNAc-terminating glycans on the cell surface (Ju et al., 2011). These glycans play a critical role in cancer progression by modulating cell adhesion, migration, and immune evasion. The Bauhinia forficata lectin (BfL) is a plant-derived protein that specifically recognizes and binds to these terminal GalNAc residues with high affinity (Silva et al., 2012). Research indicates that BfL binding can inhibit the growth and metastatic potential of various cancer cells, including breast and colon cancer, by inducing apoptosis and interfering with integrin-mediated signaling (Lubini et al., 2021). Furthermore, these glycans serve as important biomarkers for tumor progression and are being explored as targets for immunotherapy. As such, GalNAc-terminating glycans represent a significant therapeutic target for lectin-based drugs, monoclonal antibodies, and cancer vaccines.

Other names

Tn antigenGalNAc-residueN-acetyl-D-galactosamine-containing glycanTerminal GalNAcO-linked GalNAc

Binding to terminal GalNAc residues on the cell surface disrupts oncogenic signaling pathways, inhibits cell-matrix interactions, and can directly induce programmed cell death or immune-mediated lysis (Lubini et al., 2021; Ju et al., 2011).