Influence of free fatty acids on glucose uptake in prostate cancer cells

Introduction: The study focuses on the interaction between glucose and free fatty acids (FFA) in malignant human prostate cancer cell lines by an in vitro observation of uptake of fluoro-2-deoxy-o-glucose (FDG) and acetate. Methods: Human prostate cancer cell lines (PC3, CWR22Rv1, LNCaP, and DU145) were incubated for 2 h and 24 h in glucose-containing (5.5 mM) Dulbecco's Modified Eagle's Medium (DMEM) with varying concentrations of the free fatty acid palmitate (0-1.0 mM). Then the cells were incubated with [(18) F]-FDG (1 mu Ci/mL; 0.037 MBq/mL) in DMEM either in presence or absence of glucose and in presence of varying concentrations of palmitate for 1 h. Standardized procedures regarding cell counting and measuring for (18) F radioactivity were applied. Cell uptake studies with C-14-1-acetate under the same conditions were performed on PO cells. Results: In glucose containing media there was significantly increased FDG uptake after 24 h incubation in all cell lines, except DU145, when upper physiological levels of palmitate were added. A 4-fold increase of FDG uptake in PC3 cells (15.11% vs. 3.94%/108 cells) was observed in media with 1.0 mM palmitate compared to media with no palmitate. The same tendency was observed in PO and CWR22Rvl cells after 2 h incubation. In glucose-free media no significant differences in FDG uptake after 24 h incubation were observed. The significant differences after 2 h incubation all pointed in the direction of increased FDG uptake when palmitate was added. Acetate uptake in PO cells was significantly lower when palmitate was added in glucose-free DMEM. No clear tendency when comparing FDG or acetate uptake in the same media at different time points of incubation was observed. Conclusions: Our results indicate a FFA dependent metabolic boost/switch of glucose uptake in PCa, with patterns reflecting the true heterogeneity of the disease. (C) 2014 Elsevier Inc. All rights reserved.