Fig. 1.

Unlike in GBM cells, hyperpolarized [1-¹³C] lactate production is not elevated in mutant IDH1 glioma cells, associated with LDHA, MCT1 and MCT4 silencing (A) Western blots for lactate dehydrogenase A (LDHA), monocarboxylate transporter 1 and 4 (MCT1, MCT4) for BT142 and U87 glioma cells and corresponding protein levels expressed as % of U87. (B) Stack plot of hyperpolarized ¹³C MR spectra obtained at 11.7 T following injection of hyperpolarized [1-¹³C] pyruvate (δ = 172.9 ppm) in the medium of perfused BT142 IDH1-mutant cells. Production of hyperpolarized [1-¹³C] lactate could be detected at δ = 185 ppm (see insert). (C) Hyperpolarized [1-¹³C] lactate signal-to-noise ratio (SNR) as a function of time for BT142 (n = 3) and U87 (n = 3) cells, showing the significantly lower level of lactate in mutant IDH1 gliomas as compared to glioblastoma. (D) Quantitative analysis of demonstrates that the hyperpolarized [1-¹³C] lactate-to-pyruvate area-under-the-curve (AUC) was 97 ± 3% lower in BT142 compared to U87 cells (n = 3 for each cell line, ***p < 0.005).