ACAT2 negatively modulated by FOXA2 suppresses ferroptosis to expedite the aggressive phenotypes of endometrial cancer cells.

Abstract

Endometrial cancer (EC) remains a prevalent gynecological disease with a continuously rising incidence and fatality rate. Acyl coenzyme A: cholesterol acyltransferase 2 (ACAT2) has been commonly perceived as a tumor promoter in multiple human malignancies. This study was conducted to specify the role and mechanism of ACAT2 in EC, which has not been covered. The expression and prognostic significance of ACAT2 in EC samples were respectively analyzed by the ENCORI and Kaplan-Meier plotter databases. RT-qPCR and western blot examined ACAT2 and forkhead box protein A2 (FOXA2) expression in EC cells. The CCK-8 method, colony formation, and EdU staining assays detected cell proliferation. The cell cycle was detected by flow cytometry analysis. Wound healing and Transwell assays, respectively, estimated cell migration and invasion. The thiobarbituric acid reactive species (TBARS) method and BODIPY 581/591 C11 probe detected lipid peroxidation levels. FerroOrange staining estimated intracellular iron level. Western blot examined the expression of epithelial-mesenchymal transition (EMT) and ferroptosis-associated proteins. The human TFDB database predicted the binding of FOXA2 with the ACAT2 promoter, which was substantiated by ChIP and luciferase reporter assays. As a result, ACAT2 expression was increased in EC tissues and cells and associated with poor survival outcomes in EC patients. ACAT2 deletion might hinder EC cell proliferation, migration, invasion, and EMT while stimulating cell cycle arrest. Moreover, ACAT2 silencing promoted the ferroptosis of EC cells. Also, FOXA2 inactivated the transcription of ACAT2 through binding with the ACAT2 promoter. FOXA2 interference could promote the proliferation, migration, invasion, EMT, cell cycle, and ferroptosis of ACAT2-silenced EC cells, which was partially reversed by the ferroptosis activator erastin. Conclusively, ACAT2 transcriptionally inactivated by FOXA2 might contribute to the malignant progression of EC via the inhibition of ferroptosis.