Lactylation fuels nucleotide biosynthesis and facilitates deuterium metabolic imaging of tumor proliferation in preclinical models of H3K27M-mutant gliomas

Hyperactivation of glucose metabolism to lactate is a metabolic hallmark of cancer. However, the functional role of lactate in pediatric diffuse midline glioma (DMG) cells is unclear. Here, using stable isotope tracing and loss-of-function studies in clinically relevant patient-derived DMG models, we show that the oncogenic histone H3K27M mutation epigenetically up-regulates the rate-limiting glycolytic enzyme phosphoglycerate kinase 1 (PGK1) and drives lactate production from U- 13 C-glucose in DMGs. Mechanistically, lactate posttranslationally activates the nucleoside diphosphate kinase NME1 through lactylation and facilitates the synthesis of nucleoside triphosphates that are essential for DNA replication and tumor proliferation. This mechanistic link between glycolysis and nucleotide biosynthesis provides the opportunity for deuterium metabolic imaging of tumor growth and response to therapy. Spatially mapping 2 H-lactate production from 6,6- 2 H-glucose allows visualization of the metabolically active tumor lesion and provides an early readout of response to standard of care and targeted therapy that precedes extended survival and reflects pharmacodynamic alterations in tumor tissues in preclinical DMG models in vivo at clinical field strength (3 T). Overall, we have identified an H3K27M-lactate-NME1 axis that drives DMG proliferation and facilitates noninvasive in vivo metabolic imaging of DMGs.