Curcumol Enhances the Sensitivity of Gastric Cancer to Cisplatin Resistance by Inducing Ferroptosis Through the P62/KEAP1/NRF2 Pathway.

Background: Chemoresistance represented one of the challenges in the treatment of advanced gastric cancer (GC). Curcumol (CUR) was found to have a certain sensitizing effect on chemoresistance, although the mechanism was not yet fully understood. Purpose: To clarify the ability of CUR to intervene in the sensitivity of GC cells to Cisplatin (CDDP) by regulating the induction of ferroptosis through the P62/KEAP1/NRF2 pathway. Methods: An in vitro resistant cell line was established and treated with CUR for intervention. The synergy was evaluated using synergyfinder3.0 software. The impact of the combined use of CUR and CDDP on the proliferation, migration, and invasion of resistant GC cells was determined. The effect of CUR on ferroptosis in resistant GC cell lines was evaluated by measuring changes in reactive oxygen species (ROS) levels, malondialdehyde (MDA) levels, iron ion levels, and the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG). Western blotting was used to verify the expression changes of the ferroptosis-related indicator GPX4 and the differential expression of the antioxidant-related pathway P62/KEAP1/NRF2, validating the mechanism by which CUR induces ferroptosis in resistant GC cells. In vivo validation was performed using a xenograft mouse model. Results: The evaluation by synergy3.0 revealed a synergistic effect between CUR and CDDP. After treatment with CUR and CDDP, resistant GC cell lines exhibited reduced proliferation, migration, and invasion capabilities. Furthermore, the resistant GC cell lines underwent ferroptosis, with significant changes observed in ferroptosis-related indicators such as ROS, MDA, iron ions, and GSH/GSSG. The ferroptosis-related targets Glutathione Peroxidase 4 (GPX4) and the antioxidant pathway P62/KEAP1/NRF2 signaling pathway also showed significant changes. In in vivo validation, the combination of CUR and CDDP inhibited the growth of subcutaneous tumors and was found to be associated with the inhibition of subcutaneous xenografts and the GPX4 and P62/KEAP1/NRF2 signaling pathways. Conclusion: This study first revealed that CUR enhanced the sensitivity of cisplatin-resistant GC cells to CDDP by inducing ferroptosis. The combination of CUR and CDDP induces ferroptosis in cisplatin-resistant GC through the P62/KEAP1/NRF2 pathway.