The following compounds were used: Dihydroartemisinin (dihydroqinghaosu, artenimol, DHA) was a kind gift from Dominic Hoepfner (Novartis); Delta‐aminolaevulinic acid hydrochloride, 5‐ALA (Sigma Aldrich A3785‐500MG); acifluorfen, protoporphyrinogen oxidase (Ppox) inhibitor (Sigma Aldrich N11027‐250MG); piperlongumine, induces ROS (Sigma Aldrich SML0221‐5MG). For dosage responses, cells were seeded in 96‐wells (25,000/96‐well, in triplicate—where indicated) and subjected to compounds for 48 h (or 72 h if indicated in the Figure). Cell viability was assessed using automated cell counting (high‐throughput flow cytometry), Alamar Blue staining (Invitrogen, DAL1100) or CellTiter‐Glo Luminescent Assay (Promega, G7570, according to the manufacturer's protocol), respectively. For the detection of ROS, treated cells were collected, washed with 1x HBSS (without Ca2+ and Mg2+), incubated with 1 mM DHE (dihydroethidium (hydroethidine), Invitrogen, D11347) in 1× HBSS for 45 min at 37°C, washed twice and counterstained with DAPI or a viability dye (eBioscience™ Fixable Viability Dye eFluor™ 780, 65‐0865‐18) for 10 min on ice. Cells were then collected, strained, and analyzed using flow cytometry for DHE in the red fluorescent spectrum (PE channel 582/15 nm). For JC‐1 staining, treated cells were collected, washed with 1xPBS, incubated with 2 μM JC‐1 in 1xPBS (MitoProbe JC‐1 Assay Kit‐1, Invitrogen, M34152) for 35 min at 37°C, washed twice, and analyzed using flow cytometry in the red (PE channel) and green (FITC channel) fluorescence spectrum.
Taubenschmid‐Stowers J., Orthofer M., Laemmerer A., Krauditsch C., Rózsová M., Studer C., Lötsch D., Gojo J., Gabler L., Dyczynski M., Efferth T., Hagelkruys A., Widhalm G., Peyrl A., Spiegl‐Kreinecker S., Hoepfner D., Bian S., Berger W., Knoblich J.A., Elling U., Horn M, & Penninger J.M. (2023). A whole‐genome scan for Artemisinin cytotoxicity reveals a novel therapy for human brain tumors. EMBO Molecular Medicine, 15(3), e16959.