Aberrant L-Fucose accumulation and increased core fucosylation are specific metabolic liabilities in mesenchymal glioblastoma

Dysregulated metabolism in glioblastoma (GBM), the deadliest brain tumor of adults, offers an opportunity to deploy metabolic interventions as precise therapeutic strategies. To identify the molecular drivers and the modalities by which different molecular subgroups of GBM exploit metabolic rewiring to sustain tumor progression, we interrogated the transcriptome, the metabolome and the glycoproteome of human subgroup-specific GBM stem cells (GSCs). Here we report that L-Fucose abundance and core fucosylation activation are more highly enhanced in mesenchymal (MES) than in proneural (PN) GSCs; this pattern is retained in subgroup-specific xenografts and, most significantly, retrieved in subgroup-affiliated human patients' samples. Genetic and pharmacological inhibition of core fucosylation in MES GBM preclinical models results in significant reduction in tumor burden. LC/MS-based glycoproteomic screening indicates that most MES-restricted core fucosylated proteins are involved in therapeutically relevant GBM pathological processes, such as extracellular matrix interaction, cell adhesion and integrin-mediated signaling. Notably, selective L-Fucose accumulation in MES GBMs is demonstrated by pre-clinical minimally-invasive positron emission tomography (PET), implying this metabolite as a potential subgroup-restricted biomarker. Overall, these findings indicate that L-Fucose pathway activation in MES GBM offers subgroup-specific, GSC-restricted dependencies to be exploited as diagnostic markers and actionable therapeutic targets. Overall design: Gene expression profiles of proneural (PN) and mesenchymal (MES) glioblastoma (GBM) stem cells (GSCs) were compared to identify differentially expressed genes