RESUMEN
The PI3K/AKT/mTOR (PAM) signaling pathway is frequently mutated in prostate cancer. Specific AKT inhibitors are now in advanced clinical trials, and this study investigates the effect of MK2206, a non-ATP-competitive inhibitor, on the cellular metabolism of prostate cancer cells. We observed a reduction in cell motility and aerobic glycolysis in prostate cancer cells with treatment. These changes were not accompanied by a reduction in the ratio of high-energy phosphates or a change in total protein levels of enzymes and transporters involved in glycolysis. However, a decreased ratio of NAD+/NADH was observed, motivating the use of hyperpolarized magnetic resonance spectroscopy (HP-MRS) to detect treatment response. Spectroscopic experiments were performed on tumor spheroids, 3D structures that self-organize in the presence of an extracellular matrix. Treated spheroids showed decreased lactate production with on-target inhibition confirmed using IHC, demonstrating that HP-MRS can be used to probe treatment response in prostate cancer spheroids and can provide a biomarker for treatment response. Mol Cancer Res; 16(3); 453-60. ©2018 AACR.
Asunto(s)
Ácido Láctico/metabolismo , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Glucólisis/efectos de los fármacos , Compuestos Heterocíclicos con 3 Anillos/farmacología , Humanos , Masculino , Terapia Molecular Dirigida , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Neoplasias de la Próstata/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Esferoides CelularesRESUMEN
Hyperpolarized magnetic resonance spectroscopy (HP MRS) using dynamic nuclear polarization (DNP) is a technique that has greatly enhanced the sensitivity of detecting (13)C nuclei. However, the HP MRS polarization decays in the liquid state according to the spin-lattice relaxation time (T1) of the nucleus. Sampling of the signal also destroys polarization, resulting in a limited temporal ability to observe biologically interesting reactions. In this study, we demonstrate that sampling hyperpolarized signals using a permanent magnet at 1 Tesla (1T) is a simple and cost-effective method to increase T1s without sacrificing signal-to-noise. Biologically-relevant information may be obtained with a permanent magnet using enzyme solutions and in whole cells. Of significance, our findings indicate that changes in pyruvate metabolism can also be quantified in a xenograft model at this field strength.
