Decitabine combined with cold atmospheric plasma induces pyroptosis via the ROS/Caspase-3/GSDME signaling pathway in Ovcar5 cells

Background High methylation of the DFNA5 gene results in the absence of GSDME, a key protein that mediates pyroptosis, while decitabine demethylates the DFNA5 gene, resulting in high expression of the GSDME protein. Cold atmospheric plasma (CAP) is a novel anti-cancer method that induces tumor cell death. Methods The pyroptosis induced by decitabine in combination with CAP in Ovcar5 cells was evaluated. In particular, mitochondrial membrane potential was estimated by JC-1 staining, dehydrogenase (LDH) release was assessed by ELISA, Annexin V/PI staining was detected by flow cytometry, the cell cycle changes were evaluated using PI staining followed by detection by flow cytometry, and Caspase-9 cleavage, Caspase-3 cleavage and GSDME expression were evaluated by western blot. Results Decitabine resulted in high expression of the GSDME in Ovcar5 in a concentration-dependent manner and increased tumor cell sensitivity to CAP. CAP induced mitochondrial damage and activated the Caspase-9/Caspase-3 pathway. Therefore, decitabine combined with CAP induced Ovcar5 cell pyroptosis through Caspase-3 mediated GSDME cleavage. Reactive oxygen species (ROS) generated by CAP treatment played an important role in the CAP/decitabine combination-induced production of ROS, activation of Caspase-9/Caspase-3, GSDME cleavage and pyroptosis that ROS scavenger NAC inhibited all these processes. Conclusions CAP combined with decitabine induced Caspase-3 activation, which cleaved decitabine-upregulated GSDME and ediated pyroptosis.