Antitumoral Activity\nand Metabolic Signatures of Dichloroacetate,\n6‑Aminonicotinamide and Etomoxir in Breast-Tumor-Educated Macrophages

Pharmacological\ntargeting of metabolic pathways represents an appealing\nstrategy to selectively kill cancer cells while promoting antitumor\nfunctions of stromal cells. In this study, we assessed the effectiveness\nof 13 metabolic drugs (MDs) in steering <i>in vitro</i> generated\nbreast tumor-educated macrophages (TEMs) toward an antitumoral phenotype.\nFor that, the production of vascular endothelial growth factor (VEGF)\nand tumor necrosis factor α (TNF-α), two important regulators\nof tumor progression, was evaluated. Notably, dichloroacetate (DCA),\n6-aminonicotinamide (6-AN), and etomoxir decreased VEGF production\nand enhanced TNF-α release. Hence, we further clarified their\nimpact on TEM metabolism using an untargeted NMR-based metabolomics\napproach. DCA downregulated glycolysis and enhanced the utilization\nof extracellular substrates like lactate while reconfiguring lipid\nmetabolism. Several DCA-induced changes significantly correlated with\nheightened TNF-α production in response to pro-inflammatory\nstimulation. The inhibition of the pentose phosphate pathway by 6-AN\nwas accompanied by enhanced glutaminolysis, which correlated with\na decreased level of VEGF production. In etomoxir-treated TEM, inhibition\nof fatty acid oxidation was compensated through upregulation of glycolysis,\ncatabolism of intracellular amino acids, and consumption of extracellular\nbranched chain alpha-ketoacids (BCKA) and citrate. Overall, our results\noffer a comprehensive view of the metabolic signature of each MD in\nbreast TEM and highlight putative correlations with phenotypic effects.