Fig. 3: Anticancer drugs damage neosynthesized proteins followed by the generation of mtROS, which in turn enhance protein damage.

a, b MDA-MB-231 cells were treated with indicated anticancer drugs (n = 23); cytosol ROS accumulation was detected by DCFDA staining (a), and mitochondrial superoxide were detected by MitoSOX™ Red reagent (b). c MDA-MB-231 cells were treated with indicated drugs alone or in combination with GSH, DTT, Trolox, NAC, ROS catalase, or MitoQ, and K48 polyUB was detected by western blotting. d Heatmap showing the intensity of K48 polyUB induced by single drug (n = 23) treatment or in combination with NAC or MitoQ treatment. e, f MDA-MB-231 cells were treated with LAP for indicated time periods, and cytosol ROS accumulation was detected by DCFDA staining (e). Mitochondrial superoxide was detected by MitoSOX™ Red reagent (f). g MDA-MB-231 cells were treated with PON alone or in combination with MitoQ for indicated time periods, and K48 polyUB was detected by western blotting and quantified. h MDA-MB-231 cells were treated with PON alone or in combination with BTZ or CHX, and mitochondrial superoxide was detected by MitoSOX™ Red reagent. i MDA-MB-231 cells were treated with PON for indicated time periods, and K48 polyUB and protein total carbonylation were detected by western blotting. j A summary of the interplay between anticancer drugs and mitochondrial ROS in protein damage. All values are presented as mean value (at least three replicates) ± SD, and P value was calculated by comparison with the Ctr group or indicated separately (two-tailed Student’s t-test, *P < 0.05).