Fig. 2

Extracellular acidification rate with NKA inhibition. a Seahorse XFe24 glycolytic stress test of extracellular change in pH for the MDA-MB-231 cancer cells (± SEM representing biological reproducibility of n = 3 biological repeats where each n = 3 technical repeats were first averaged). Complete time courses for the other cell lines are given in Supplementary Fig. S8. The stress test comprised 10 mM glucose, 1 μM oligomycin, and 100 mM 2-deoxy-D-glucose indicated by arrows. b Oxygen consumption rate (OCR) measured simultaneously with the ECAR data in panel a. c Plot of the measured ECAR glycolytic rate vs OCR during the 10 mM glucose time window defined in Supplementary Fig. S6 (n = 3 biological repeats each with n = 3 technical repeats) showing a reduction in glycolytic rate and no change in OCR. Quantified extracellular acidification rate corresponding to glycolytic rates during the 10 mM glucose time window (left panels) and their corresponding OCR (right panels), in control and ouabain treated cells: d 4T1: ECAR (p = 0.24), OCR (p = 0.39); e MDA-MB-231: ECAR decreased by 52% (p = 0.006), OCR (p = 0.40); f HCC1954: ECAR decreased by 21% (p = 0.08), OCR (p = 0.66); g MCF-7: ECAR decreased by 38% (p = 0.015), OCR (p = 0.16). n = 3 biological repeats each with n = 3 technical repeats, significance was assessed using a nested unpaired t-test. ns p > 0.05, * p < 0.05, ** p < 0.01