Fig. 3

CHCHD4 expression confers increased tumour cell sensitivity to CI inhibitors. a Graph shows relative growth of control U2OS (control) cells, two independent CHCHD4 (WT)-expressing cell clones (WT.cl1, WT.cl3) and CHCHD4 (C66A/C68A)-expressing cells incubated for 72 h in the absence or presence of rotenone using a 2-fold dilution series (top concentration, 1 μM). Data are presented for each time point for rotenone-treated relative to untreated. n = 3, mean ± SD, *p < 0.05. b As in a, using a 10-fold dilution series of sodium azide (top concentration, 100 μM). n = 3, mean ± SD. c Images of control U2OS cells, CHCHD4 (WT)-expressing cells (WT.cl1, WT.cl3) and CHCHD4 (C66A/C68A)-expressing cells, either untreated (NT) or treated with rotenone (500 nM) for 3 h. MitoSOX Red ROS indicator (5 μM) was added for 30 min prior to live cell imaging by fluorescence microscopy. d Graph shows the percentage of the mean fluorescence intensity quantified from images of cells described in c. n = 5 images per condition, mean ± SD, n.s. not significant, *p < 0.05, **p < 0.01. e Images of cells described in c, either untreated (NT) or treated with sodium azide (NaAzide, 5 mM) for 3 h. MitoSOX Red ROS indicator (5 μM) was added for 30 min prior to live cell imaging by fluorescence microscopy