Robust detection of oncometabolic aberrations by 1H-13C heteronuclear single quantum correlation in live cells and intact tumors ex-vivo

Extensive efforts have been made to use non-invasive 1H magnetic resonance (MR) spectroscopy to quantify metabolites that are diagnostic of specific disease states. Within the realm of precision oncology, these efforts have largely centered on quantifying 2-hydroxyglutarate (2-HG) in tumors harboring isocitrate dehydrogenase 1 (IDH1) mutations. As many metabolites have similar chemical shifts, the resulting 1H spectra of intact biological material are highly convoluted, limiting the application of 1H MR to high abundance metabolites. Hydrogen-Carbon Heteronuclear single quantum correlation 1H-13C HSQC is routinely employed in organic synthesis to resolve complex spectra but has received limited attention for biological studies. Here, we show that 1H-13C HSQC offers a dramatic improvement in sensitivity compared to one-dimensional (1D) 13C NMR and dramatic signal deconvolution compared to 1D 1H spectra in an intact biological setting. Using a standard NMR spectroscope without specialized signal enhancements features such as magic angle spinning, metabolite extractions or 13C-isotopic enrichment, we obtain well-resolved 2D 1H-13C HSQC spectra in live cancer cells, in ex-vivo freshly dissected xenografted tumors and resected primary tumors. We demonstrate that this method can readily identify tumors with specific genetic-driven oncometabolite alterations such as IDH mutations with elevation of 2-HG as well as PGD-homozygously deleted tumors with elevation of gluconate. These data support the potential of 1H-13C HSQC as a non-invasive diagnostic tool for metabolic precision oncology.