Eradication of Therapy-Resistant Cancer Stem Cells by Novel Telmisartan Derivatives.

The present structure-activity relationship study investigates the development of novel chemosensitizers targeting therapy-resistant cancer stem cells (CSCs). We used 4'-((2-propyl-1-benzo[]imidazole-1-yl)methyl)-[1,1'-biphenyl]-2-carboxylic acid, derived from the angiotensin II type 1 receptor blocker telmisartan, as a lead structure, demonstrating that the biphenyl moiety is essential for chemosensitizing activity. Introducing a methyl carboxylate or carboxamide instead of the COOH-group significantly enhanced this effect, leading to the development of highly potent compounds.

Circumventing Imatinib resistance in CML: Novel Telmisartan-based cell death modulators with improved activity and stability.

Drug resistance presents a significant challenge in cancer therapy, which has led to intensive research in resistance mechanisms and new therapeutic strategies. In chronic myeloid leukemia (CML), the introduction of Imatinib, the first tyrosine kinase inhibitor (TKI), drastically changed the outcome for patients. However, complete remission still cannot be achieved in a large number of patients in the long term.

Transferrin Receptor-Mediated Cellular Uptake of Fluorinated Chlorido[,'-bis(salicylidene)-1,2-phenylenediamine]iron(III) Complexes.

Fluorinated chlorido[salophene]iron(III) complexes (salophene = ,'-bis(salicylidene)-1,2-phenylenediamine) are promising anticancer agents. Apoptosis and necrosis induction have already been described as part of their mode of action. However, the involvement of ferroptosis in cell death induction, as confirmed for other chlorido[salophene]iron(III) complexes, has not yet been investigated.

Design, synthesis, and biological evaluation of novel halogenated chlorido[N,N'-bis(salicylidene)-1,2-bis(3-methoxyphenyl)ethylenediamine]iron(III) complexes as anticancer agents.

Iron(III) complexes based on N,N´-bis(salicylidene)ethylenediamine (salene) scaffolds have demonstrated promising anticancer features like induction of ferroptosis, an iron dependent cell death. Since poor cellular uptake limits their therapeutical potential, this study aimed to enhance the lipophilic character of chlorido[N,N'-bis(salicylidene)-1,2-bis(3-methoxyphenyl)ethylenediamine]iron(III) complexes by introducing lipophilicity improving ligands such as fluorine (X1), chlorine (X2) and bromine (X3) in 5-position in the salicylidene moieties. After detailed characterization the binding to nucleophiles, logP values and cellular uptake were determined.

Iron(III)-salophene catalyzes redox cycles that induce phospholipid peroxidation and deplete cancer cells of ferroptosis-protecting cofactors.

Ferroptosis, a lipid peroxidation-driven cell death program kept in check by glutathione peroxidase 4 and endogenous redox cycles, promises access to novel strategies for treating therapy-resistant cancers. Chlorido [N,N'-disalicylidene-1,2-phenylenediamine]iron (III) complexes (SCs) have potent anti-cancer properties by inducing ferroptosis, apoptosis, or necroptosis through still poorly understood molecular mechanisms. Here, we show that SCs preferentially induce ferroptosis over other cell death programs in triple-negative breast cancer cells (LC ≥ 0.