Fig. 7
Metabolic pathways affected by SLC25A1. a, b Metabolomic analysis with LC-MS of SLC25A1-expressing spheres versus control spheres a and of SLC25A1-expressing spheres untreated versus treated with CTPI-2 b. In a, 1412 metabolites were quantified, 181 of which showed statistically significant changes (p < 0.05). In b, 413 metabolites were quantified and 91 metabolites showed statistically significant changes (p < 0.05). Analysis was performed with Morpheus, Metaboanalyst and Ingenuity Pathway analysis (IPA). One minus Pearson correlation’ was used for hierarchical clustering of the metabolites. Panel a shows metabolites induced by SLC25A1 relative to control cells, and panel b shows metabolites that were downregulated by CTPI-2 in SLC25A1-expressing spheres. Pathways that are common in the two comparisons are highlighted in green. c, d Extracellular acidification rates (ECAR) and lactate levels in the indicated growth conditions and in the presence or absence of CTPI-2. e Proposed model for the effects of SLC25A1 and CTPI-2 in monolayer and spheres (see also text for explanation). f Phosphofructokinase (PFK) activity was assessed in cells first grown in monolayer or spheres for 36 h and then treated with citrate (10 mM) overnight. The following day, 5 mM citrate was re-added to the media and cells were either mock treated (lanes 1, 4) or treated with CTPI-2 (lanes 2, 3, 5, 6) for 3 h, before quenching and assessment of PFK activity. Bars represent the standard deviation, asterisks refer to ***P ≤ 0.001 by unpaired T-test
