Heterozygous mutations in
NADP-dependent
isocitrate dehydrogenases (IDH) define the large majority of diffuse
gliomas and are associated with hypermethylation of
DNA and
chromatin. The metabolic dysregulations imposed by these mutations, whether dependent or not on the oncometabolite
D-2-hydroxyglutarate (D2HG), are less well understood. Here, we applied mass spectrometry imaging on intracranial patient-derived xenografts of IDH-mutant versus IDH wild-type
glioma to profile the distribution of metabolites at high anatomical resolution in situ This approach was complemented by in vivo tracing of labeled nutrients followed by liquid chromatography-mass spectrometry (LC-MS) analysis. Selected metabolites were verified on clinical specimen. Our data identify remarkable differences in the
phospholipid composition of
gliomas harboring the IDH1 mutation. Moreover, we show that these
tumors are characterized by reduced
glucose turnover and a lower energy potential, correlating with their reduced aggressivity. Despite these differences, our data also show that D2HG overproduction does not result in a global aberration of the central
carbon metabolism, indicating strong adaptive mechanisms at hand. Intriguingly, D2HG shows no quantitatively important
glucose-derived label in IDH-mutant
tumors, which suggests that the synthesis of this oncometabolite may rely on alternative
carbon sources. Despite a reduction in
NADPH,
glutathione levels are maintained. We found that genes coding for key
enzymes in de novo
glutathione synthesis are highly expressed in IDH-mutant
gliomas and the expression of
cystathionine-β-synthase (CBS) correlates with patient survival in the oligodendroglial subtype. This study provides a detailed and clinically relevant insight into the in vivo metabolism of IDH1-mutant
gliomas and points to novel metabolic vulnerabilities in these
tumors.