Tanshinone IIA induces ferroptosis in gastric cancer cells through p53-mediated SLC7A11 down-regulation

Gastric cancer represents a malignant type of cancer worldwide. Tanshinone IIA (Tan IIA), a pharmacologically active component isolated from the rhizome of the Chinese herb Salvia miltiorrhiza Bunge (Danshen), has been reported to possess an anti-cancer effect in gastric cancer. However, its mechanisms are still not fully understood. In the present study, we found that Tan IIA induced ferroptosis in BGC-823 and NCI-H87 gastric cancer cells. Tan IIA increased lipid peroxidation and up-regulated Ptgs2 and Chac1 expression, two markers of ferroptosis. Ferrostatin-1 (Fer-1), an inhibitor of lipid peroxidation, inhibited Tan IIA caused-lipid peroxidation and Ptgs2 and Chac1 expression. In addition, Tan IIA also up-regulated p53 expression and down-regulated xCT expression. Tan IIA caused decreased intracellular glutathione (GSH) level and cysteine level and increased intracellular reactive oxygen species (ROS) level. p53 knockdown attenuated Tan IIA-induced lipid peroxidation and ferroptosis. Tan IIA also induced lipid peroxidation and ferroptosis in BGC-823 xenograft model, and the anti-cancer effect of Tan IIA was attenuated by Fer-1 in vivo. Therefore, Tan IIA could suppress the proliferation of gastric cancer via inducing p53 upregulation-mediated ferroptosis. Our study have identified a novel mechanism of Tan IIA against gastric cancer, and might provide a critical insight into the application of Tan IIA in gastric cancer intervention.