Inhibitors of oxidative phosphorylation down-regulate MTMP and prevent etoposide-induced accumulation of p53. (A) MOLT-3 cells were incubated with oligomycin (10 μg/mL), rotenone (0.04 mM), TTFA (0.2 mM) and FCCP (1 and 5 μM, left and right dot plots, respectively) for 3 hours and assessed for MTMP levels by JC-1 (red-green fluorescence ratios indicated; x- and y-axes show 4-decade log scale). (B) Flow cytometric detection of p53 protein levels in MOLT-3 cells cultured for 3 hours in the presence of etoposide (1 μM) and/or oligomycin (10 μg/mL) (x-axis shows fluorescence intensity, 4-decade log scale). The dotted vertical line indicates the peak position of the isotype control. (C) Kinetics of p53 accumulation in MOLT-3 cells incubated with etoposide with or without oligomycin (10 μg/mL). (D) Inhibition of etoposide-induced p53 accumulation in MOLT-3 cells by mitochondrial inhibitors (10 μg/mL, 0.04 mM, 0.2 mM of oligomycin, rotenone and TTFA, respectively). MOLT-3 cells were incubated with or without etoposide (1 μM) for 3 hours.