Figure 2: 14-3-3σ inhibits cancer metabolic reprogramming.
From: The cell cycle regulator 14-3-3σ opposes and reverses cancer metabolic reprogramming
(a) The broad suppressive impact of 14-3-3σ on cancer metabolism. NMR was used to measure the concentrations of important metabolites in HCT116 14-3-3σ+/+ (WT), HCT116 14-3-3σ−/−. (b) 14-3-3σ decreased the ECAR of HCT116 in vitro. ECARs were measured by a Seahorse Extracellular Efflux Analyzer XF96 (XF96). Average±s.d., n=3, P<0.05. (c) 14-3-3σ reduced the ECAR of MDA-MB-231 in vitro. ECARs were measured by XF96. Average±s.d., n=3, P<0.05. (d) 14-3-3σ inhibited the OCR of HCT116 in vitro. OCRs were measured by XF96. Average±s.d., n=3, Student’s t-test,*P<0.05. (e) 14-3-3σ diminished the OCR of MDA-MB-231 in vitro. OCRs were measured by XF96. Average±s.d., n=3, Student’s t-test,*P<0.05. (f) 14-3-3σ inhibited cancer glutaminolysis as measured using ammonia production assays. Cellular lysates of MDA-MB-231 TetR 14-3-3σ cells were collected to measure the ammonia production rate using an ammonia production kit (Sigma-Aldrich). Average±s.d., n=3, Student’s t-test,*P<0.05. (g) 14-3-3σ decreased cancer mitochondrial mass of MDA-MB-231 in vitro. MDA-MB-231 TetR 14-3-3σ cells were stained with Mitochondria Tracker Green FM (Molecular Probes, Invitrogen), which stains functional mitochondria. Mitochondrial Tracker Green FM signals were analysed using a BD Biosciences FACS Canto flow cytometer. The FlowJo X software was used to build Mitochondrial Tracker Green FM histograms. Noninduced MDA-MB-231 TetR 14-3-3σ cells were used as a control. (h) Induction of 14-3-3σ expression decreased ATP concentrations in the colorectal cancer cell line HCT116 and the triple-negative breast cancer cell line MDA-MB-231 in vitro. HCT116 14-3-3σ−/− TetR 14-3-3σ and MDA-MB-231 TetR 14-3-3σ cancer cells were grown in doxycycline-containing medium (5 ng ml−1) for inducing Flag-14-3-3σ expression for 3 days. Noninduced cells were used as a control. Cell lysates from HCT116 14-3-3σ−/− TetR 14-3-3σ cells and MDA-MB-231 TetR 14-3-3σ cells were collected for measuring ATP concentration using an ATP Bioluminescence CLS II kit (Roche) and a luminometer (Biotek). Average±95% CI, n=3, analysis of variance (ANOVA),*P<0.05.
