Tanshinone I Stimulates Pyroptosis of Cisplatin-Resistant Gastric Cancer Cells by Activating the NF-κB/Caspase-3(8)/GSDME Signaling Pathway

Cisplatin (DDP) resistance frequently occurs in gastric cancer (GC) therapy. Tanshinone I is a liposoluble phenanthraquinone compound present in the roots of Salvia miltiorrhiza Bunge (Danshen). In this study, we aimed to explore the effects of tanshinone I on modulating DDP resistance of GC cells in vitro and in vivo. DDP-resistant GC cell models (BGC823/DDP and SGC7901/DDP) were established, and their viability, proliferation, migration, lactate dehydrogenase activity, reactive oxygen species (ROS) generation, and pyroptosis were assessed after DDP treatment with or without tanshinone I. In addition, a mouse model with subcutaneously transplanted GC tumors was established to confirm the effects of tanshinone I and DDP on tumor growth and cell pyroptosis. The results revealed that tanshinone I inhibited DDP-resistant GC cell proliferation and migration; increased intracellular ROS levels; and activated cell pyroptosis by enhancing the levels of cleaved caspase-8, cleaved caspase-3, GSDME-NT, phospho-IKK-α/β, and nuclear factor kappa-B (NF-κB). GSDME knockdown weakened these effects of tanshinone I on DDP-resistant GC cells. Furthermore, DDP combined with tanshinone I inhibited the growth of subcutaneously transplanted GC tumors in mice by reducing cell proliferation and inducing pyroptosis. In conclusion, tanshinone I reversed DDP resistance of GC cells by stimulating pyroptosis, by activating NF-κB/caspase-3(8)/GSDME signaling pathway.