EGR1 promotes ferroptosis in endometrial cancer cells by increasing NOX4 transcription.

Abstract

Objective: To investigate the role of early growth response 1 (EGR1) in the progression of endometrial cancer (EC) and to elucidate the molecular mechanism by which EGR1 regulates ferroptosis, with a focus on NADPH oxidase 4 (NOX4) as a downstream mediator.

Methods: An EC xenograft model was established in nude mice. EGR1 was overexpressed in HEC-1B cells, and cell proliferation and migration were assessed using CCK-8, colony formation, and Transwell assays. Ferroptosis-related indicators (Fe²⁺, MDA, GSH, and lipid ROS) and related proteins (GPX4, SLC7A11, and IREB2) were measured. The ferroptosis inhibitor Fer-1 was used for rescue experiments. Gene and protein expression were analyzed via RT-qPCR, western blotting, and immunohistochemistry. The transcriptional regulation of NOX4 by EGR1 was validated using chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays.

Results: EGR1 expression was downregulated in EC. Overexpression of EGR1 inhibited the proliferation and migration of HEC-1B cells and suppressed tumor growth in vivo. EGR1 overexpression induced ferroptosis, as evidenced by increased levels of Fe²⁺, MDA, and lipid ROS; decreased GSH levels; downregulation of GPX4 and SLC7A11; and upregulation of IREB2. These effects were reversed by Fer-1. Mechanistically, EGR1 directly bound to the NOX4 promoter and increased its transcription, leading to increased ROS production and thereby facilitating ferroptosis.

Conclusion: EGR1 inhibits the progression of EC at least in part through transcriptionally activating NOX4, which promotes ROS accumulation and contributes to ferroptosis induction. This study provides a theoretical basis for targeting EGR1 as a potential therapeutic strategy for treating EC.