Abstract 12: Combinatorial intervention with natural compounds induces key metabolic modulations for prostate cancer prevention and treatment
Authors: Lu Xiyuan , Wang Bo , Saha Achinto , Sentandreu Enrique , Lodi Alessia , DiGiovanni John , Tiziani Stefano 
Published: July 2016

Prostate cancer is one of the three most relevant cancer types in men, and it ranks second in death rate and first in newly diagnosed cancer cases according to the US cancer statistics 2015. In recent years, the impact of nutrition on cancer prevention has been increasingly recognized. Accordingly the study of natural compounds for cancer prevention and treatment has drawn attention, mainly for the low toxicity to normal tissues.

In this study, a natural compound library of 140 compounds was screened on cultured mouse prostate tumor cells from HiMyc mice (HMVP-2 cells), and ATP and reactive oxygen species (ROS) bioluminescence measurements were performed. Based on ATP and ROS results, three hits, ursolic acid (UA), curcumin (CURC) and resveratrol (RES) were selected for more in depth metabolomic and lipidomic analyses. High-resolution liquid chromatography mass spectrometry (HPLC-MS) and magnetic resonance spectroscopy (MRS) were applied for large scale untargeted metabolic and lipidomic profiling of intra and extracellular prostate cancer extracts after treatment with the three drugs and their combinations at different time points. We next performed an in vivo study on an allograft mouse model of prostate cancer by injecting HMVP-2 spheroids into FVB/N mice.

After 12 hours of treatment, 115 metabolites in KEGG database and 12 classes of lipids (664 features) were included in the study. Principal component analysis (PCA) showed that the combination of UA and CURC exerts the most profound metabolic perturbation in HMVP2 cells compared to the individual treatment or the combination of other selected hits. Further data mining showed that the CURC+UA had a synergistic effect on cell metabolism by altering metabolic pathways associated with alanine, aspartate, proline and glutamate metabolism. Moreover, key intermediates in glycerophospholipid and ceramide metabolism were highly perturbed in CURC +UA indicating a relevant response of lipid mechanism to treatment with the combination of these agents. The in vivo mouse model produces palpable tumors within 10-14 days post injection. Dietary administration of CURC+UA and UA+RES showed significant inhibition of tumor growth compared to the administration of the individual compounds, with CURC+UA yielding the most effective combination.

In summary, amongst the 140 screened compounds, CURC, UA and RES exerted the most prominent metabolic effects on prostate cancers cells, and the combined CURC+UA treatment showed a synergistic effect on cell metabolism and significantly affected key metabolic pathways active in mitochondria, most likely via lipid metabolisms.

Citation Format: Xiyuan Lu, Bo Wang, Achinto Saha, Enrique Sentandreu, Alessia Lodi, John DiGiovanni, Stefano Tiziani. Combinatorial intervention with natural compounds induces key metabolic modulations for prostate cancer prevention and treatment. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 12.