Telomerase reverse transcriptase (TERT) expression is indispensable for tumor immortality. Non-invasive methods of imaging TERT can, therefore, report on tumor proliferation and response to therapy. Here, we show that TERT expression is associated with elevated levels of the redox metabolite NADH in multiple cancers, including glioblastoma, oligodendroglioma, melanoma, neuroblastoma, and hepatocellular carcinoma. Mechanistically, TERT acts via the metabolic regulator FOXO1 to upregulate nicotinamide phosphoribosyl transferase, which is the key enzyme for NADH biosynthesis. Importantly, deuterium magnetic resonance spectroscopy (2H-MRS), which is a novel, clinically translatable metabolic imaging modality, can be leveraged for imaging TERT-linked NADH in preclinical tumor models in vivo. Since NADH is essential for pyruvate flux to lactate, 2H-MRS following administration of 2H-labeled pyruvate non-invasively visualizes TERT expression and reports on early response to therapy. Collectively, our study provides insights into the mechanisms of TERT-linked metabolic reprogramming and, importantly, establishes 2H-MRS as a pan-cancer strategy for imaging tumor immortality.
Real-time metabolic imaging of tae-induced alterations in tumor metabolism using dynamic nuclear polarization carbon-13 magnetic resonance spectroscopy in vivo
