EXTRACELLULAR VESICLES FROM OBESITY-CONDITIONED PREADIPOCYTES INDUCE A DISTINCT PRO-MIGRATORY AND METABOLIC PHENOTYPE IN BREAST CANCER CELLS

INTRODUCTION AND OBJECTIVES: Obesity-associated inflammation may alter adipose-breast cancer communication. We investigated extracellular vesicles (EVs) from obese-educated (OB-PEVs) and eutrophic-educated (EUT-PEVs) preadipocytes. MATERIAL AND METHODS: Preadipocytes were conditioned with secretome from subcutaneous adipose tissue of obese (n=5) or eutrophic (n=8) donors. EVs were isolated at 20,000 × g and characterized by nanoparticle tracking analysis and CD9/CD81. Tumor necrosis factor (TNF) and interleukin-6 (IL6) expression was assessed after conditioning. MDA-MB-231 migration was evaluated by wound healing with metabolic inhibitors. Colony formation, invasion, metabolism and preliminary MCF-7 migration were also assessed. RESULTS AND CONCLUSION: EV number and size did not differ between groups, and preparations were CD9/CD81-positive. Conditioning increased TNF and IL6 expression. OB-PEVs increased MDA-MB-231 migration by 1.77-fold, whereas EUT-PEVs did not significantly alter migration. Fatty acid oxidation inhibition reduced basal, EUT-PEV- and OB-PEV-associated migration by 3.17-, 2.94- and 2.91-fold; palmitate increased migration by 2.29-fold. Glycolysis inhibition with 2-deoxy-D-glucose (2-DG) increased basal and EUT-PEV-associated migration by 1.76- and 1.83-fold, without significantly affecting OB-PEV-induced migration. Glutaminolysis inhibition reduced OB-PEV-induced migration by 1.98-fold, with no significant effect on basal or EUT-PEV-associated migration. Colony formation and invasion were unchanged; preliminary MCF-7 assays suggested increased migration after OB-PEVs. OB-PEV-treated cells showed lower lactate than EUT-PEV-treated cells; fatty acid oxidation inhibition increased lactate and decreased glucose-6-phosphate dehydrogenase activity. Both EV groups reduced AMP-activated protein kinase activation. These findings indicate a distinct OB-PEV pro-migratory/metabolic phenotype sensitive to fatty acid oxidation and glutaminolysis inhibition.