Targeting the FTO-ACSL4 Pathway: A Novel Mechanism for Sanguinarine Chloride-Induced Ferroptosis in Endometrial Cancer.

Objective: Endometrial cancer (EC) remains a significant clinical challenge, particularly for patients with advanced or recurrent disease. This study aims to investigate the effects of Sanguinarine Chloride (S.C), a natural benzophenanthridine alkaloid with broad anti-tumor properties, on EC cell growth and invasion, and to elucidate its underlying molecular mechanisms. Methods: S.C's effects on EC cell viability, proliferation, invasion, and apoptosis were evaluated using CCK-8, EdU, colony formation, 3D matrigel drop assay, FACS and Western blotting (WB). To evaluate its effects on ferroptosis, malondialdehyde (MDA) assay kits, DCFH-DA and the C11 BODIPY581/591 probe, were employed. The molecular mechanisms through which S.C regulates FTO-ACSL4 axis were investigated using plasmid transfection and WB. Additionally, a mouse xenograft model derived from EC cells was established to evaluate the in vivo effects of S.C and its molecular mechanisms, utilizing hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC) and WB. Results: S.C significantly inhibited EC cell growth and invasion. It induced cell death primarily through ferroptosis, as inhibitors (Ferrostatin-1, Deferoxamine) reversed this effect. S.C downregulated the RNA demethylase FTO, leading to increased ACSL4 expression, enhanced lipid peroxidation, suppression of the NRF2-GPX4 axis, and activated NCOA4-mediated ferritinophagy. Knocking down or pharmacologically inhibiting ACSL4 reduced S.C-induced ferroptosis. Furthermore, in a murine xenograft model, S.C significantly suppressed tumor growth, which was associated with consistent alterations in these ferroptosis-related markers in vivo. Conclusions: Our findings reveal that S.C triggers ferroptosis in EC via the novel FTO-ACSL4 axis, highlighting its potential as a therapeutic agent and identifying the FTO-ACSL4 pathway as a promising target for endometrial cancer treatment.