Cutting back on the carbs

Glycans are essential components in maintaining many important biological processes within the body, and can be found in forms ranging from simple monomers to complex polymeric assemblies. On the cell surface, oligosaccharides are presented and recognized by an array of carbohydrate-binding proteins (lectins), such as sialic acid-binding Ig-like lectins (Siglecs), selectins, and galectins. The interactions play critical roles in cellular adhesion, migration, inflammation, and immunological responses through cellular recognition and signaling activities (1). Dysregulation of glycan–lectin interactions has been implicated in both autoimmune diseases and cancer (2, 3). Consequently, the glycome and its interacting partners have attracted a great deal of attention as targets for therapeutics, ranging from small molecules (4) to antibodies (5, 6). In PNAS, Xiao et al. (7) describe a new method to cut back on the carbohydrate structures of cancer cells in a manner that leads to the activation of the immune system. The work represents a new glycoengineering strategy that may have therapeutic applications. Drugs leading to the inhibition of glycan–lectin interactions have had considerable success in the treatment of pathogenic infections and several other glycan-based diseases (4, 8). These agents function by disrupting interactions between binding partners or by inhibiting enzymes within the glycome machinery, such as glycosidases or glycosyltransferases (9). Heparin is the most widely used glycan-derived drug, acting …