Fig. 5: BH3 mimetics exhibit off-target activities that can suppress ferroptotic cell death.

A Measurement of GPX4 activity. Cells were treated with 10 µM WEHI-539, 2 µM ferrostatin-1 (FER) and 100 nM RSL3 as indicated. Data show mean ± range of two technical replicates from one of two independent experiments. B Pfa1 cells with inducible GPX4 knock out were co-treated with WEHI-539 and tamoxifen (Tam) for 72 h. Cell death was determined by PI uptake. Antagonism was calculated by the Webb´s fractional product. GPX4 loss was confirmed by immunoblotting. Data show means from one representative out of three independent experiments. C U87 cells were treated with RSL3 (100 nM), WEHI-539 (10 μM), following depletion of BCL-XL expression. Cell death was determined by PI uptake performing live cell imaging. Data shown are means ± SD of three technical replicates from one out of two independent experiments. D U87 cells were treated with RSL3 (100 nM), S63845 (10 μM), following depletion of MCL-1 expression. Cell death was determined by PI uptake performing live cell imaging. Data shown are means ± SD of three technical replicates from one out of two independent experiments. E Quantification of cell death, calculated as percentage of PI-positive cells. Cells were stimulated with the indicated concentrations of RSL3 and WEHI-539 for 24 h. Data shown are means of two technical replicates. One representative example of three independent experiments is presented.