Imaging glutamine utilization in a prostate cancer xenograft model

Motivation: MRI agents that can monitor abnormal glutamine utilization, a hallmark of many aggressive cancers, are not clinically available. Goal(s): We investigated the utility of glutamine as a chemical exchange saturation transfer (CEST) agent to evaluate its utilization. Approach: Phantoms revealed contrast differences between glutamine and its metabolic products. Dynamic CEST images (in vivo) were acquired in 2 prostate cancer xenograft models after intravenous injection of glutamine. MALDI (matrix-assisted laser desorption/ionization) images of the same tumors (ex vivo) were collected for validation. Results: CEST and MALDI images could distinguish prostate tumors derived from cell lines with known differences in glutamine utilization. Impact: The potential of CEST (chemical exchange saturation transfer) MRI to evaluate glutamine utilization was evaluated in preclinical prostate cancer models (DU-145 and LNCaP). CEST enhancement images upon infusion of glutamine could distinguish tumors that differed in glutamine utilization.