Related Experiment Video
Updated: Jun 29, 2025
04:01
Author Spotlight: Tracing the Ferroptotic Signatures and Cell Death Dynamics in Medulloblastoma for Advanced Therapeutics
Published on: March 15, 2024
959
Strong Protection by 4-Hydroxyestrone against Erastin-Induced Ferroptotic Cell Death in Estrogen Receptor-Negative
Hongge Wang1,2, Ming-Jie Hou1, Lixi Liao1
1Shenzhen Key Laboratory of Steroid Drug Discovery and Development, School of Medicine, The Chinese University of Hong Kong, Shenzhen 518172, China.
Biochemistry
|April 3, 2024
Summary
4-hydroxyestrone (4-OH-E1) inhibits protein disulfide isomerase (PDI), a key mediator of ferroptosis. This finding offers a new strategy to protect against ferroptosis-associated cell death in human breast cancer cells.
Area of Science:
- Cell Death Biology
- Biochemistry
- Cancer Research
Background:
- Ferroptosis is a regulated cell death pathway driven by iron-dependent lipid peroxidation.
- Protein disulfide isomerase (PDI) is implicated as a mediator and potential therapeutic target in ferroptosis.
- Estrogen metabolites are increasingly recognized for their diverse biological roles beyond hormone signaling.
Purpose of the Study:
- To investigate 4-hydroxyestrone (4-OH-E1), an estrogen metabolite, as a modulator of ferroptosis.
- To determine if 4-OH-E1 can inhibit PDI and protect against ferroptosis.
- To elucidate the mechanism of 4-OH-E1's action in human breast cancer cells.
Main Methods:
- Biochemical assays (pull-down, CETSA) to assess 4-OH-E1 binding to PDI.
- Computational modeling to predict the interaction between 4-OH-E1 and PDI.
- Cell-based assays using PDI knockdown (siRNA) and ferroptosis inducers in MDA-MB-231 cells.
- Measurement of iNOS activity and nitric oxide (NO) accumulation.
Main Results:
- 4-OH-E1 directly binds to PDI in vitro and in intact cells.
- 4-OH-E1 inhibits PDI's catalytic activity, evidenced by computational modeling showing hydrogen bonds with His256.
- 4-OH-E1 protects against chemically induced ferroptosis in estrogen receptor-negative breast cancer cells.
- PDI inhibition by 4-OH-E1 or cystamine, and PDI knockdown, reduces iNOS activity and NO levels.
Conclusions:
- 4-OH-E1 is a novel, potent inhibitor of PDI.
- 4-OH-E1 confers protection against ferroptosis in human breast cancer cells independently of the estrogen receptor.
- The findings highlight PDI as a critical target for ferroptosis inhibition and suggest potential therapeutic applications for estrogen metabolites.
