Conditions for 13C NMR detection of 2-hydroxyglutarate in tissue extracts from isocitrate dehydrogenase-mutated gliomas

C-13 NMR (nuclear magnetic resonance) spectroscopy of extracts from patient tumor samples provides rich information about metabolism. However, in isocitrate dehydrogenase (IDH)-mutant gliomas, C-13 labeling is obscured in oncometabolite 2-hydroxyglutaric acid (2HG) by glutamate and glutamine, prompting development of a simple method to resolve the metabolites. J-coupled multiplets in 2HG were similar to glutamate and glutamine and could be clearly resolved at pH 6. A cryogenically cooled C-13 probe, but not J-resolved heteronuclear single quantum coherence spectroscopy, significantly improved detection of 2HG. These methods enable the monitoring of C-13-C-13 spin-spin couplings in 2HG expressing IDH-mutant gliomas. (C) 2015 Elsevier Inc. All rights reserved.