Fig 1.
Establishment of IDH1–wild type (WT), IDH1–mutant (–R132H), IDH2–WT, and IDH2–mutant (–R172K) overexpressing F98 cell lines.
(A) Construction map of IDH1/2–WT or –R132H/–R172K lentiviral vector. (B) GFP expressions in Mock, IDH1/2–WT or –R132H/–R172K vector transduced F98 cells by using Fluorescence–activated cell sorting (FACS). (C) GFP–tagged gene expressions of the F98 cells confirmed by fluorescent microscopic images. (D) Immunoblot analysis where IDH1–R132H or IDH2–R172K specific antibodies were detected only in the mutated epitopes of F98 IDH1–R132H or IDH2–R172K, respectively.
Fig 2.
2–hydroxyglutarate (2HG) levels in the brain samples as measured by ex vivo liquid chromatography–mass spectrometry (LC–MS).
The brain samples were collected from the tumor regions (F98 IDH1/2–WT, IDH1–R132H, and IDH2–R172K) and the contralateral, normal regions (CN VOI). The relative intensity of 2HG in Group A (n = 12) and Group B (n = 7) ranged 0.06x105~0.15x105 and 3.14x105~5.47x105, respectively. Those 6 samples with intermediate 2HG levels (3 from IDH1–R132H and 3 from IDH2–R172K) were excluded in the final data analysis, and then the Group A and Group B were treated as 2HG–absent and 2HG–present, respectively.
Fig 3.
Representative 1H–MRS spectra.
(A and C) A contralateral normal brain region (CN VOI). (B and D) A brain tumor region (tumor VOI) with F98 IDH2–R172K glioma. All spectra were post–processed with voxel–specifically obtained spectral baselines by using either MRUI (A and B) or LCModel (C and D). The resulting residual of fit and the 2HG spectral components are also shown, which were denoted by dashed lines in ~1.8–2.3 ppm. (2HG: 2–hydroxyglutarate, GABA: gamma–aminobutylic acid, Gln: glutamine, Glu: glutamate, Lac: lactate, mI: myo–inositol, NAA: N–acetylaspartate, NAAG: N–acetylaspartylglutamate, Tau: taurine, tCho: total choline, tCr: total creatine, tNAA: total N–acetylaspartate).
Table 1.
The results of 2HG detection by 1H–MRS.
Tn, true-negative; Tp, true-positive; Fn, false-negative; Fp, false-positive; U, uncertain case (CRLB >20%); n/a, not available;