Induction of Ferroptosis in Glioblastoma and Ovarian Cancers by a New Pyrrole Tubulin Assembly Inhibitor

We synthesized new aroyl diheterocyclic pyrrole (ARDHEP) 15 that exhibited the hallmarks of ferroptosis. Compound 15 strongly inhibited U-87 MG, OVCAR-3, and MCF-7 cancer cells, induced an increase of cleaved PARP, but was not toxic for normal human primary T lymphocytes at 0.1 μM. Analysis of the levels of lactoperoxidase, malondialdehyde, lactic acid, total glutathione, and ATP suggested that the in vivo inhibition of cancer cell proliferation by 15 went through stimulation of oxidative stress injury and Fe2+ accumulation. Quantitative polymerase chain reaction analysis of the mRNA expression in U-87 MG and SKOV-3 tumor tissues from 15-treated mice showed the presence of Ptgs2/Nfe2l2/Sat1/Akr1c1/Gpx4 genes correlated with ferroptosis in both groups. Immunofluorescence staining revealed significantly lower expressions of proteins Ki67, CD31, and ferroptosis negative regulation proteins glutathione peroxidase 4 (GPX4) and FTH1. Compound 15 was found to be metabolically stable when incubated with human liver microsomes.