Berberine-mediated Ferroptosis through System Xc/GSH/GPX4 Axis Inhibits Metastasis of Nasopharyngeal Carcinoma.

Nasopharyngeal carcinoma (NPC) is a malignant tumor that is highly prevalent in Southeast China, and its metastasis remains an unresolved clinical problem. Ferroptosis, a type of nonapoptotic cell death, is a critical pathway in tumor metastasis. Berberine (BBR), a plant alkaloid, has been explored as a potential anti-NPC metastatic agent; however, the underlying mechanisms are unknown. Here, we showed that BBR exerted its anti-metastasis role by inhibiting system Xc/GSH/GPX4 axis-driven ferroptosis. The present study demonstrated for the first time that BBR induced ferroptosis in NPC cells by increasing reactive oxygen species, lipid peroxidation and cellular Fe and that the ferroptosis inhibitors Ferrostatin-1 and Deferoxamine mesylate rescued BBR-induced NPC cell death. Moreover, the ferroptotic characteristics of BBR-treated NPC cells were observed using transmission electron microscopy. Mechanistically, system Xc (SLC7A11 and SLC3A2) and GSH levels were found to be suppressed after treatment with BBR. We demonstrated that the system Xc/GSH/GPX4 axis was a critical mediator of BBR-induced ferroptosis. Furthermore, GPX4, a key inhibitor of lipid peroxidation, was greatly suppressed by BBR at both protein and mRNA levels. Molecular docking results showed a strong interaction between GPX4 and BBR. Notably, GPX4 overexpression reversed the effect of BBR-induced ferroptosis in NPC cells. Finally, BBR-mediated inhibition of NPC metastasis was validated using a mouse model. Taken together, our data suggest that BBR induced ferroptosis of NPC cells via suppressing the system Xc/GSH/GPX4 axis, provides new insights into the mechanism of BBR anti-NPC metastasis.