Cepharanthine Triggers Ferroptosis in Gastric Cancer by PINK1/FUNDC1-Mediated Mitophagy-Dependent GPX4 Degradation.

Cepharanthine (CEP), a natural compound derived from the plant Stephania cephalantha Hayata, demonstrates pharmacological properties including anti-inflammatory, immuno-regulatory, antiviral, antitumor and antiparasitic effects. Due to its insidious progression and drug resistance, gastric cancer (GC) continues to have a high incidence and mortality rate worldwide. While the great potential of ferroptosis in cancer therapy is well-established, and CEP has shown potential antitumor activity, the role of ferroptosis in CEP's impact on GC remains unknown. Our aim in this study is to uncover what role ferroptosis has in the impact of CEP on GC. To investigate this, cell viability was measured by CCK-8 assay, and the effect of CEP on GC cell ferroptosis was assessed by Fe2[Formula: see text], DCFH-DA, and TEM. Integrated transcriptomic analyses revealed the critical pathways involved in CEP-induced ferroptosis, and JC-1, MitoSOX Red, Mito-Tracker, and immunofluorescence staining were used to evaluate mitophagy. The interaction between CEP and PINK1 was further confirmed by molecular docking, CETSA, and DARTS, and a xenograft tumor was used both to evaluate the effect of CEP on GC and to verify its mechanism through immunohistochemistry and western blotting. It was found that CEP could induce ferroptosis in GC cells by inducing an increase in reactive oxygen species, malondialdehyde, and intracellular Fe[Formula: see text] levels, and that it had little effect on normal gastric epithelial cells. Mechanistically, CEP binds directly to RUNX2, PINK1, and FUNDC1 to thereby activate PINK1-mediated mitophagy, prompt FUNDC1 to recruit GPX4 into mitochondria, and ultimately lead to the autophagic degradation of GPX4 and ferroptosis. A subcutaneous tumor model in nude mice confirmed the ferroptosis-associated antitumor efficacy of CEP in vivo. This study highlights that the natural compound CEP exerts its antitumor effects by activating mitophagy-dependent ferroptosis through a multi-target effect. CEP thus shows great promise as a potential drug candidate for GC treatment.