Figure 3

Compound 4 induces ferroptosis. (A) Overview of ferroptosis (as described in⁵). (B) Similar effects of compound 4, erastin, and sulfasalazine (SSZ) on NCI-H522 cells. Cells were exposed to the compounds indicated and viable cells quantified 2 days later using methylene blue. (C) Elevation of ROS in NCI-H522 cells exposed to 10 μM compound 4 is blocked by β-mercaptoethanol (βME). Cells were exposed to the indicated compounds for 4 hours and stained with H2DCFDA. Stain was extracted and quantified using a fluorescence plate reader. (D) Measurement of lipid oxidation. NCI-H522 cells were exposed to DMSO or compound 4 for 10 hours. Bodipy 581/591-C11, a membrane bound ROS sensor was added at the time compounds were added. Fluorescence was detected by FACS and mean fluorescent intensities of triplicate samples compiled in part (E). As expected, the lipid ROS scavenger liproxstatin blocked the oxidation of the dye in response to 4. Bars throughout represent averages and associated standard deviations.