Mehrdad Pourfathi1, 2, Stephen J. Kadlecek1, Harrilla Profka1, Hoora Shaghaghi1, Moses Darpolor1, Kiarash Emami1, Nicholas N. Kuzma1, Jan H. Ardenkjr-Larsen3, Rahim R. Rizi1, Janet A. Sawicki4
1Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, United States; 3GE Healthcare, Brndby, Denmark; 4Lankenau Institute for Medical Research, Wynnewood, PA, United States
Lactate dehydrogenase (LDH), shown to be unregulated in ovarian cancer, may result in elevated lactate concentrations in the tumors. Using [113C] pyruvic acid (hyperpolarized via DNP), we sought to infer elevated LDH levels by detecting a more rapid approach to the equilibrium lactate:pyruvate ratio. The data was acquired by slice-selective spectroscopy of ovarian area from six mice and fitted to a simple model incorporating (a) the forward and backward conversion of pyruvate/lactate in steady-state metabolism and (b) spin-lattice relaxation of pyruvate polarization over time. We observed higher levels of LDH activity (in both directions) associated with ovarian-tumor-bearing animals.