Taraxerol induces ferroptosis in breast cancer by targeting Nrf2 transcriptional activity to promote MIB2-mediated GPX4 ubiquitination

Background

Eradicating tumors through targeted ferroptosis represents a novel approach to BC treatment. Taraxerol, a natural triterpenoid derived from dandelions, has shown anti-tumor effects. However, the ferroptosis dependency of Taraxerol’s anticancer effects remains to be elucidated.

Purpose

This study aimed to explore the effects and molecular mechanism of action of taraxerol on ferroptosis in BC.

Methods

The effects of Taraxerol on the proliferation, lipid peroxidation, iron accumulation, and glutathione (GSH) and malondialdehyde (MDA) levels in BC cells were investigated. Western blotting, qRT-PCR, Co-IP, and dual-luciferase reporter assays were used to detect Taraxerol-induced protein expression and regulation. Network pharmacology and molecular docking were employed to explore the regulation of ferroptosis-related signaling pathways and specific proteins by Taraxerol. The in vivo anti-tumor effect mediated by Taraxerol was explored using a xenograft tumor model.

Results

Taraxerol markedly inhibited BC cell proliferation both in vitro and in vivo, increasing lipid peroxidation and Fe²⁺ levels, and reducing GSH levels. Moreover, Taraxerol triggered ferroptosis in BC cells by targeting Nrf2, which is involved in the PI3K/AKT/mTOR signaling pathway. It also promoted the ubiquitin-mediated degradation of GPX4 by regulating the interaction between Nrf2 and the E3 ubiquitin ligase MIB2.

Conclusion

Our findings are the first to demonstrate that Taraxerol mediates ferroptosis in BC via the Nrf2/MIB2/GPX4 axis, representing a potential therapeutic candidate for BC treatment.