Ferdia Aidan Gallagher1,2, Mikko I. Kettunen2,3, De-en Hu2,3, Sam E. Day2,3, Magnus Karlsson4, Anna Gisselsson4, Mathilde H. Lerche4, Kevin M. Brindle2,3
1Radiology, University of Cambridge, Cambridge, UK; 2CRUK Cambridge Research Institute, Cambridge, UK; 3Biochemistry, University of Cambridge, Cambridge, UK; 4Imagnia AB, Malm, Sweden
The number of metabolites that can be hyperpolarized using Dynamic Nuclear Polarization is increasing. Here we show that [1-13C]glutamic acid can also be polarized. The metabolism of hyperpolarized glutamate to -ketoglutarate, catalyzed by the enzyme alanine transaminase, was detected in vitro and in vivo in tumor models. As non-polarized -ketoglutarate is below the threshold for MRS detection, this presents a new method for probing tumor metabolism.