BIX‐01294 enhanced chemotherapy effect in gastric cancer by inducing GSDME‐mediated pyroptosis

Adjuvant chemotherapy in combination with surgery is expected to be a curative strategy for gastric cancer. However, drug resistance remains an obstacle in effective chemotherapy. Therefore, understanding the potential mechanisms of chemotherapy induced gastric cancer cell death is of great importance. We demonstrated that BIX‐01294 (BIX) at low concentration could induce autophagic flux by converting LC3B‐I to LC3B‐II and directly activate autophagy associated cell death in gastric cancer cell lines at high concentration. BIX at low concentration could help obtain sensitivity of gastric cancer cells to chemotherapy with significantly reduced cell viability. Interestingly, BIX combined Cis (BIX + Cis) treated SGC‐7901 cells display pyroptosis related cell death with large bubbles blown around the membrane, significantly decreased cell viability, elevated lactate dehydrogenase release and increased percentage of propidium iodide and Annexin‐V double positive cells. Furthermore, the cleavage of gasdermin E (GSDME) and caspase‐3 but not GSDMD was detected by immunoblotting and the knockout of GSDME switched pyroptosis into apoptosis in the BIX + Cis combined treated group. Furthermore, the deficiency of Beclin‐1 to inhibit BIX induced autophagic flux completely blocked BIX + Cis combined treated induced cell pyroptosis related cell death. Additionally, BIX + Cis in vivo treatment could inhibit tumor growth, which could be reversed by the deficiency of Beclin‐1 and be delayed by the deficiency of GSDME. In conclusion, our data was the first to reveal that BIX enhanced the anticancer chemotherapy effect by induced GSDME‐mediated pyroptosis through the activation of autophagic flux in gastric cancer cells.