Fig. 5

Peroxisome-promoting compounds sensitize U-2OS cells to ferroptosis induction. A U-2OS cells were treated with ferroptosis inducer (RSL3 (1 μM) or erastin (2 μM)), proteasome inhibitor MLN2238 (1 μM) or drug combination with/without ferroptosis inhibitor Fer-1 (2 μM) for 24 h. Cell death events were analyzed by PI staining. B Summary of percentage of cell death events in U-2OS cells after treatment with ferroptosis inducer (1 μM RSL3 or 2 μM erastin), chemicals (1 μM) or drug combination with/without ferroptosis inhibitor Fer-1 (2 μM). N = 3 independent experiments. ***p < 0.001 versus the Fer-1 treatment group; ^##p < 0.01 and ^###p < 0.001 versus RSL3 treatment; ^$$p < 0.01 and ^$$$p < 0.001 versus erastin treatment; ^&&&p < 0.001 versus control group. C U-2OS cells with or without MLN2238 treatment (1 μM, 24 h) were exposed to 200 μM H₂O₂ for 30 min. Cells were labeled with DCFDA, and the relative ROS levels were determined by flow cytometry. N = 3 independent experiments. *p < 0.05; **p < 0.01. D Spheroids derived from U-2OS cells were treated with RSL3 (1 μM), MLN2238 (1 μM) or RSL3 + MLN2238 for 24 h. The spheroids were then stained with PI and imaged under EVOS 7000 microscope, scale bar: 100 μm