Repurposing nitazoxanide as a novel ferroptosis inducer for triple-negative breast cancer via dual disruption of iron homeostasis and the β-catenin/GPX4 axis

BACKGROUND: Ferroptosis induction is a promising triple-negative breast cancer (TNBC) therapy, but current inducers are suboptimal. Nitazoxanide (NTZ), an FDA-approved antiparasitic with anticancer and redox activity, may be repurposed as a ferroptosis inducer, yet its effects and mechanisms in TNBC are unclear. METHODS: Anti-TNBC effects of NTZ were assessed in MDA-MB-231 and Hs578T cells via viability, clonogenicity, migration/invasion, and zebrafish xenografts. Ferroptosis was evaluated by iron levels, lipid peroxidation, GSH/GSSG, MDA, ROS, and mitochondrial TEM. Mechanisms were studied by docking, western blot, qPCR, apoptosis assay, cycloheximide chase, and pharmacological rescue. RESULTS: NTZ inhibited proliferation, migration, and invasion in vitro and tumor growth in vivo, and induced ferroptosis. Mechanistically, it disrupted iron homeostasis by upregulating TFR1 and downregulating FPN1, causing iron overload and lipid peroxidation, and promoted β-catenin degradation, which transcriptionally suppressed GPX4, weakening antioxidant defense. Both β-catenin stabilization and ferroptosis inhibition reversed these effects. CONCLUSION: NTZ is repurposed as a ferroptosis inducer for TNBC via dual disruption of iron homeostasis and β-catenin/GPX4 axis, providing a strong preclinical rationale for its therapeutic use.