α-Hederin causes ferroptosis in triple-negative breast cancer through modulating IRF1 to suppress GPX4

Abstract

Background

Breast cancer ranks first in the global incidence rate of cancer among women. Triple-negative breast cancer (TNBC) is considered to be the most dangerous type because of the lack of specific therapeutic targets and rapid progression. The emergence of ferroptosis provides a new therapeutic perspective for TNBC. α-Hederin is a triterpenoid saponin derived from the traditional Chinese medicine Ivy, which has been proven to have anti-cancer effects on various cancers, but its efficacy and mechanism of inducing ferroptosis in TNBC remain to be further clarified.

Object

To investigate the effect and mechanism of α-Hederin induced ferroptosis in TNBC.

Method

Cell viability was measured by CCK-8 assay, and cell proliferation and migration were evaluated by clone assay and scratch assay. The effect of α-Hederin on TNBC cell apoptosis was assessed by flow cytometry. Transcriptomics searches for critical pathways. Intracellular and lipid reactive oxygen species and Fe²⁺and Fe were detected by DCFH-DA probe, FerroOrange fluorescent probe and C11-BODIPY fluorescent probe, and the contents of malondialdehyde and reduced glutathione were detected by MDA and GSH kits. Erastin was used as a positive control for ferroptosis and Ferrrostatin-1(Fer-1) as an inhibitor. The relationship between α-Hederin and GPX4, IRF was analyzed by western blot and si-RNA, and the association was further confirmed by molecular simulation docking, external SPR experiments, and luciferase experiments. Constructing xenograft mouse models and human derived organoid models to evaluate the anti-TNBC efficacy of α-Hederin, and verifying the efficacy and ferroptosis mechanism of the drug in vivo through HE staining and IHC.

Result

α-Hederin significantly inhibited the progression of TNBC. In vitro, α-Hederin decreased cancer cell viability through ferroptosis, increased glutathione degradation and MDA production, and promoted intracellular Fe²⁺ and ROS production, whereas Fer-1, an ferroptosis inhibitor, reversed this effect. Mechanistically, molecular docking and SPR experiments showed binding of α-Hederin to the key regulator IRF1, and knockdown/overexpression of IRF1 significantly affected the expression of GPX4, a downstream target of the ferroptosis pathway. In vivo, α-Hederin prevented tumor growth in xenograft and organoid models via the IRF1/GPX4 axis.

Conclusion

We proved for the first time in this research that α-Hederin exerts anti-TNBC effects through a novel IRF1/GPX4 ferroptosis pathway.