Objective To investigate whether recombinant Newcastle disease virus(rL-RVG)induces iron death in gastric cancer cells through Nrf2-GCLC-GPX4 pathway.Methods After human gastric cancer HGC-27 cells were treated with rL-RVG,Newcastle disease virus(NDV)and PBS solution(control group),respectively,cell proliferation,invasion and migration were detected by CCK-8 assay and Transwell invasion assay and cell scratch test.Ferroptosis accelerator(erastin),and nuclear factor E2 related factor 2(Nrf2)accelerator(TBHQ)and inhibitor(ML385)were added respectively as controls.The content of malondialdehyde(MDA)in each treatment group was detected by lipid oxidation kit.The content of reactive oxygen species(ROS)was detected by DCFH-DA fluorescent probe and flow cytometry.Western blotting and immunofluorescence assay were employed to measure the expression levels of Nrf2-GCLC-GPX4 pathway related proteins.Results Compared with the control group,the survival rate of HGC-27 cells were significantly decreased after rL-RVG and NDV treatment in a dose-and time-dependent manner,and the effect was more significant in the rL-RVG treatment group(P＜0.05).The migration and invasion abilities of HGC-27 cells were obviously inhibited in the NDV and rL-RVG treatment groups,and the latter had more notable inhibition than the former.The protein levels of Nrf2,GCLC,SLC7A11 and GPX4 were statistically decreased(P＜0.05),and the contents of MDA and ROS were increased(P＜0.05)in the virus treatment groups than the control group,with the increasing or decreasing trend more significant in the rL-RVG group than the NDV group.What's more,the protein levels of SLC7A11 and GPX4 were decreased in the erastin group(P＜0.05).Compared with the control group,those of Nrf2,GCLC,SLC7A11 and GPX4 were increased in the TBHQ group and decreased in the ML385 group(P＜0.05),while the contents of MDA and ROS were decreased and increased respectively in the above 2 groups(P＜0.05).Compared with the rL-RVG group,the rL-RVG+TBHQ group and rL-RVG+ML385 group had enhanced and reduced protein expressio of Nrf2,GCLC,SLC7A11 and GPX4,respectively(P＜0.05),while the contents of MDA and ROS were in opposite trends(P＜0.05).Conclusion rL-RVG can induce ferroptosis of gastric cancer cells through Nrf2-GCLC-GPX4 pathway,and then inhibit the growth of tumor cells.

Objective To investigate the role of sodium-hyaluronate-modified calcium peroxide nanoparticles(SH-CaO2 NPs)in inducing pyroptosis in human gastric cancer cells and its possible mechanisms.Methods Transmission electron microscopy(TEM),X-ray diffraction(XRD),infrared spectroscopy,and zeta potential test were used to confirm the synthesis of SH-CaO2 NPs.Cell scratch assay and CCK-8 assay were employed to observe the impacts of SH-CaO2 NPs on the migration and proliferation of human gastric cancer cell line HGC-27.The generation of reactive oxygen species(ROS)was observed with confocal laser scanning microscopy(CLSM)and quantified with flow cytometry in the cells after SH-CaO2 NPs treatment or with pretreatment with ROS inhibitor NAC.Furthermore,the effects of pretreatment of NLRP3 inhibitor(MCC950)and Caspase-1 inhibitor(VX765)on the proliferative activity and on expression of their own and their downstream GSDMD in HGC-27 cells were also investigated with CCK-8 assay,immunofluorescence assay and Western blotting.Results TEM images,XRD,infrared spectroscopy,and zeta potential test confirmed the successful preparation of SH-CaO2 NPs.Cell scratch assay and CCK-8 assay showed that application of SH-CaO2 NPs for 24 h significantly inhibited the proliferation of HGC-27 cells(P＜0.001),while,CLSM and flow cytometry indicated the treatment also promoted the production of ROS(P＜0.001).Pretreatment of ROS inhibitor NAC resulted in up-regulation of NLRP3,and increased expression levels of cleaved Caspase-1 and N-terminal fragment of GSDMD(P＜0.001),while pretreatment of both NLRP3 inhibitor and Caspase-1 inhibitor could reverse the process.Conclusion SH-CaO2 NPs inhibit cell viability of human gastric cancer,which may mediate the inflammatory response and pyroptosis by activating the ROS/NLRP3/Caspase-1/GSDMD signaling pathway.