Mounia Beloueche-Babari1, Slawomir Wantuch1, Harold G Parkes1, Markella Koniordou1, Vaitha Arunan1, Thomas R Eykyn1, Paul D Smith2, and Martin O Leach1
The
monocarboxylate transporter 1 (MCT1), which mediates the bidirectional movement
of molecules such as lactate and pyruvate, is upregulated in cancer and constitutes
a promising drug target. Using MRS we investigate the impact of the MCT1
inhibitor AZD3965, currently in phase-I clinical trials, on human cancer cell
metabolism to assess potential for pharmacodynamic biomarker discovery. We show
that AZD3965 inhibits lactate efflux and blocks hyperpolarised 13C-pyruvate-lactate
exchange in human cancer cells in an MCT4-dependent manner. Thus, intracellular
lactate and hyperpolarized 13C-pyruvate-lactate exchange are promising
metabolic imaging biomarkers for monitoring the action of AZD3965 and
potentially other MCT1 inhibitors.