Abstract 5082: Metabolic profiling of drug response in prostate cancer cells following PI3K, MAPK and HSP90 inhibition using magnetic resonance spectroscopy

Abstract

Abstract The phosphatidylinositol-3-kinase (PI3K) and the mitogen-activated protein kinase (MAPK) pathways contribute to the regulation of several key cell functions including proliferation, differentiation, and oncogenic transformation. Deregulation of both these pathways is commonly observed in many human cancers. Due to the involvement of these signaling pathways in oncogenesis and tumor growth, inhibitors of PI3K and MAPK pathways are under investigation as targeted anticancer treatments. Besides promoting perturbations of these signaling pathways, inhibitors of PI3K and MAPK have been recognized to affect cellular metabolism. Here, we used multinuclear in vitro and ex vivo magnetic resonance spectroscopy (MRS) to investigate the changes induced on the metabolism of PC3 prostate cancer cells following treatment with LY294002, an inhibitor of the PI3K pathway, U0126 an inhibitor of the MAPK pathway and 17AAG which induces the simultaneous inhibition of MAPK and PI3K by targeting the heat-shock protein 90 (HSP90). The intracellular metabolites were extracted using a modified Bligh-Dyer extraction. For the MRS analysis, the polar and apolar fractions were dried and redissolved in 90% H2O-10% D2O phosphate buffer and chloroform, respectively. A fully untargeted metabolomics approach was used to investigate the common and disparate metabolic effects of these drug treatments. The principal component analysis (PCA) of the full proton MRS datasets was characterized by tight grouping within each treatment dataset and complete separation between the control and each of the three treatments groups. In particular, the first principal component, recapitulating about 45% of the variability, separated the control-group from the LY294002 and the 17AAG treatments (which in turn separated along PC2, ∼28% of the variability). Cells treated with U0126 separated from the control group only along the PC2 axis. The modulation upon treatment of the intracellular concentrations of metabolites in the glycolytic pathway indicated that glucose accumulates and lactate levels drop following 17AAG and LY294002 treatments, and vice-a-versa upon administration of U0126 likely indicating changes in glycolytic enzymes and HIF1alpha. The perturbations observed in the concentrations of metabolites of the Kennedy pathway recapitulate findings previously reported for other cell lines, i.e. phosphocholine levels drop upon treatment with LY294002 and U0126, but increase following administration of 17AAG. These observations demonstrate the potential of MRS metabolomic analysis to identify the metabolic consequences of anticancer treatments thus informing on cancer cell metabolism and identifying potential noninvasive biomarkers of response. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5082.