Fig 1: Glucose-derived mitochondrial GSH prevents Fenton reaction-like mediated cell death of CuHi cells. A, Seahorse measurement of basal OCR in response to glucose starvation in CuLo and CuHi in the absence and presence of exogenous pyruvate in 786-O and RCC4 cells. Data are normalized to Hoechst staining. B, MitoSOX measurement of mitochondrial superoxide accumulation in response to glucose starvation (16 hours) and treatment with exogenous pyruvate in CuLo and CuHi 786-O (P value from paired t test) and RCC4 (P values from unpaired t test) cells. C, CM-H2DCFDA measurement of cellular hydrogen peroxide in response to glucose starvation and treatments with exogenous pyruvate and BSO in CuLo and CuHi 786-O and RCC4 cells. BSO concentrations: 10 μmol/L for 786-O and 25 μmol/L for RCC4 cells. D, Effect of GPT2 knockdown on the accumulation of H2O2 in response to pyruvate rescue of glucose starvation in CuHi cells. E, Effect of SLC25A22 knockdown on the accumulation of H2O2 in response to pyruvate rescue of glucose starvation in CuHi cells. F, Effect of exogenous GSH-EE on the accumulation of H2O2 in response to glucose starvation in CuHi cells. G, Effect of SLC25A40 knockdown on the pyruvate rescue of glucose starvation-induced cell death in CuHi cells. H, Effect of SLC25A40 knockdown on the accumulation of H2O2 in response to pyruvate rescue of glucose starvation in CuHi cells. I, Cell death caused by glucose starvation is prevented by treatment with PEG-catalase. 786-O cells: 250 U/mL, RCC4 cells 500 U/mL. P values from two-tailed t test. J, Knockdown of COX4I1 diminishes H2O2 generation in response to glucose starvation. K, Knockdown of COX4I1 partially rescues cytotoxicity induced by glucose starvation. L, Glucose starvation–induced death of CuHi cells was prevented by removing Cu or treatment with Cu chelator [tetrathiomolybdate (TTM), 30 μmol/L] in 786-O and RCC4 cells. M, Gross images of tumors formed by 786-O cells expressing nontargeting (NT) or indicated shRNAs in mice fed with a CuHi diet. Control NT tumors are the same as in Fig. 2Q and R. Scale bar, 1 cm. N, Weight of tumors at collection. O, Model of the proposed role of CuCOX in coupling ROS and GSH production. Means ± SEM shown; unless otherwise indicated, P values were calculated from one-way ANOVA with the Holm–Šidák posttest. See also Supplementary Fig. S5.