Page 148 - 2020_08-Haematologica-web

Y. Saito et al.
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Figure 4. EVI1 activates oxidative phosphorylation (OXPHOS) via glutaminolysis. (A) Mitochondrial mass in Evi1/MF9 (red line) cells was equivalent to that in WT/MF9 (black line) (n=3). (B and C) Reactive oxygen species (ROS) levels and mitochondrial superoxide production were significantly higher in Evi1/MF9 (n=3). (D and E) The oxygen consumption rate (OCR)/extracellular acidification rate (ECAR) ratio under conditions of basal respiration in Evi1/MF9 (D) and EVI1high acute myeloid leukemia (AML) cell lines (E) was significantly higher than that in WT/MF9 cells and EVI1low AML cell lines. (F) The XF Mito Fuel Flex Test calculates the rate of oxidation of a given fuel as a percentage of oxidation of all three fuels being tested. Fuel dependency (black or gray) is a measurement of reliance on a particular fuel pathway to maintain baseline respiration. Fuel flexibility (white) is the ability of cells to increase oxidation of a particular fuel to compensate for inhibition of an alternative fuel pathway. Evi1/MF9 showed an increased dependency on glutamine, but not glycolysis and fatty acids. (G) Evi1/MF9 cells showed increased resist- ance to glucose starvation. (H) Evi1/MF9 cells were sensitized to glutamine starvation. *P<0.05; **P<0.005; ***P<0.0005 (Student’s t-test). (I) The OCR of gluta- minolysis inhibitor (BPTES)-treated WT/MF9 leukemia cells remained unchanged. The basal and maximum OCR of BPTES-treated Evi1/MF9 leukemia cells were lower than those of vehicle-treated cells. (J) Schematic representation of metabolic reprogramming upon EVI1 expression.
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haematologica | 2020; 105(8)