Fig. 1: Mitochondrial and redox metabolisms are reprogrammed in relapsed PDAC xenografts.
A Schematic of experimental protocol. Pieces of tumor from PDX were implanted in the subcutaneous space of recipient female Swiss nude mice. When tumors reached 200 mm3 volume, mice were assigned to treatment groups and treated for one month (30 days), then the treatment was stopped and the recurrence was followed. Mice were sacrificed according to the ethical limit point. B Tumor volume from start of 1-month treatment in the two different PDAC PDX relapse models, PDAC084T treated with the combination gemcitabine plus perhexiline (Gem+Perx) and PDAC032T treated with gemcitabine (Gem), and untreated controls. PDAC xenografts always relapse after complete regression induced by chemotherapy. C Mitochondrial mass (Mito mass), mitochondrial membrane potential (MMP), mitochondrial superoxide anions (Mito O2.−), and total reactive oxygen species (Total ROS) levels were measured by flow cytometry with the MitoTracker Deep Red, TMRM, MitoSOX red, and CellROX orange fluorescent probes, respectively, in relapsed tumors at ethical limit point. Median fluorescence intensity (MFI) is shown relative to that of unlabeled cells. Each dot corresponds to one mouse, and the bars show the mean ± SD. D Total ATP level and percentages of mitochondrial and glycolytic ATP were measured using the Cell viability assay (Cell-Titer Glo Kit). For this, specific inhibitors were used: oligomycin (1 µM) or 2-DG (100 mM) to determine percentages of mitochondrial and glycolytic ATP, respectively. Unpaired student’s t-test was used for statistical analyzes comparing each group with its untreated control group. *, **, *** and **** correspond to p < 0.05, 0.01, 0.001, and 0.0001, respectively; ns non-significant difference.
