A New Approach in Cancer Treatment: Discovery of Chlorido[,'-disalicylidene-1,2-phenylenediamine]iron(III) Complexes as Ferroptosis Inducers.

Chlorido[,'-disalicylidene-1,2-phenylenediamine]iron(III) complexes generate lipid-based ROS and induce ferroptosis in leukemia and neuroblastoma cell lines. The extent of ferroptosis on the mode of action is regulated by simple modifications of the substituents at the 1,2-phenylenediamine moiety. In HL-60 cells, the unsubstituted lead exclusively caused ferroptosis. For instance, a 4-F substituent shifted the mode of action toward both ferroptosis and necroptosis, while the analogously chlorinated derivative exerted only necroptosis. Remarkably, cell-death in NB1 neuroblastoma cells was solely induced by ferroptosis, independent of the used substituents. The effects were higher than that of the therapeutically applied drug cisplatin. These data clearly demonstrate for the first time that not only iron ions but also iron salophene complexes are potent ferroptosis inducers, which can be optimized as antitumor agents.