O-GlcNAcylation of UGDH regulates its activity and remodels the extracellular matrix to facilitate tumor growth.

The tumor microenvironment is an immunosuppressive niche that contributes to tumor growth by downregulating immune cell functions or restraining immune cell infiltration. The underlying mechanisms are not still poorly understood. Here, we demonstrate that O-linked N-acetylglucosamine (O-GlcNAcylation), a prevalent form of protein glycosylation, contributes to establishing the immunosuppressive niche through regulating the metabolic and non-metabolic functions of uridine diphosphate glucose dehydrogenase (UGDH). Tumor cells carrying O-GlcNAcylation-deficient UGDH showed reduced xenograft tumor growth and improved survival in mice. Cytometry by time-of-flight (CyTOF) analysis suggests UGDH O-GlcNAcylation negatively correlates with cytotoxic CD8