Compound Library Screening for Bioactive Inhibitors

An 1,833-member bioactive compound library, and an independent 86-member PI3K signaling inhibitor library comprising mTOR, PI3K and AKT pathway inhibitors, were obtained from Selleck Chemicals and stored at −80°C. Erastin2, annotated as compound 35MEW28 (Ref.^{51 (link)}) and ML162 were synthesized by Acme Bioscience. Erastin was the kind gift of B. Stockwell (Columbia). Chemical used (supplier) were: DMSO, ferrostatin-1, thapsigargin, tunicamycin, cycloheximide, L-arginine, D-arginine and L-citrulline (Sigma-Aldrich Corporation); bortezomib, rapamycin, etoposide and buthionine sulfoximine (Thermo-Fisher Scientific); INK 128, AZD8055, vinblastine, camptothecin, sorafenib, bazedoxifene, raloxifene and JTC-801 (Selleck Chemicals); and GCN2iB (MedChemExpress). buthionine sulfoximine was dissolved directly into cell media. All other drugs were prepared as stock solutions in DMSO. Stock solutions were stored at −20˚C.