| Triple negative breast cancer is extremely difficult to cure due to its high heterogeneity,high recurrence rate,high metastasis rate and poor prognosis.Recent studies have shown that triple-negative breast cancer is highly sensitive to ferroptosis induced by oxidative stress,thus ferroptosis may be a potential target for triple-negative breast cancer treatment.Ferroptosis is a new type of non-apoptotic programmed cell death discovered in recent years,and its occurrence is mainly dependent on the accumulation of iron ions to induce lipid peroxide accumulation on the membrane causing cell membrane rupture,while iron ions in cells are mainly stored in mitochondria,so mitochondria play an important role in the regulation of cellular ferroptosis.It was found that mitochondrial iron ion efflux mediated by oxidative stress-induced mitochondrial damage is an important factor in the regulation of cellular ferroptosis,but the intrinsic molecular mechanisms of regulation still need to be further elucidated.Peroxiredoxin 1(Prx Ⅰ),a member of the 2-Cys Prxs family mainly found in the cytoplasmic matrix,has been reported as an antioxidant protein that is highly sensitive to oxidative stress,but little is known about its role in the regulation of ferroptosis.A previous study found that Prx I was highly expressed in triple-negative breast cancer patient samples,and the prognosis rate of such patients was significantly higher,and the ferroptosis promoter Erastin upregulated Prx I protein expression in human triple-negative breast cancer cell line(MDA-MB-436),and Erastin promoted mitochondrial damage in MDA-MB-436 cell line with Prx I knockdown,suggesting that Prx I may regulate ferroptosis by protecting against mitochondrial oxidative damage.Therefore,this paper investigates the mechanism of oxidative stress-mediated mitochondrial damage in ferroptosis in MDA-MB-436 cells,elucidates the regulatory role of Prx Ⅰ on Erastin-induced ferroptosis in MDA-MB-436 cells and its molecular mechanism,provides a basic theory for ferroptosis in triple-negative breast cancer,and provides a molecular target for the treatment of triple-negative breast cancer.In this study,Prx Ⅰ knockdown MDA-MB-436 cell line was constructed by lentiviral vector,Mock MDA-MB-436(blank vector control group)was treated with different concentrations of Erastin,sh Prx Ⅰ MDA-MB-436(Prx Ⅰ knockdown group)cells,and cell survival rate was detected by MTT Assay;fluorescence microscopy was used to detect The intracellular as well as mitochondrial ROS levels and mitochondrial membrane potential changes under Erastin treatment;intracellular iron ion and malondialdehyde levels were detected by iron ion assay kit and malondialdehyde assay kit;protein immunoblotting technique was used to detect PI3K/Akt/GSK3β signaling pathway,cellular ferroptosis-related protein expression levels,apoptosis The protein immunoblotting technique was used to detect the expression levels of PI3K/Akt/GSK3β signaling pathway,cellular ferroptosis-related protein and apoptosis-related protein.The results showed that sh Prx Ⅰ MDA-MB-436 intracellular and mitochondrial levels of reactive oxygen species,iron ions and malondialdehyde increased significantly,the expression levels of HO-1 and P53,GSK3β increased,the expression levels of P-PI3 K,PI3K,P-Akt and Akt decreased,and the expression levels of ferroptosis regulatory protein NRF2 decreased.protein NRF2 protein expression level decreased,p-GSK3β expression level decreased,and apoptosis protein expression level did not show statistical differences.The occurrence of PrxⅠ-regulated ferroptosis was inhibited by pretreatment with reactive oxygen scavengers N-acetyl-L-cysteine(NAC),GSK3β inhibitor(Licl)and Akt activator(SC79).In summary,we conclude that 1,knockdown of Prx Ⅰ promotes Erastin-induced ferroptosis in MDA-MB-436 cells;2,knockdown of Prx Ⅰ increases Erastin-induced mitochondrial reactive oxygen species accumulation and mitochondrial damage in MDA-MB-436 cells;3,knockdown of Prx Ⅰ induces mitochondrial outer membrane through PI3K/Akt/GSK3β signaling pathway VDAC channel opening promotes mitochondrial iron ion efflux.In conclusion,this paper illustrates the molecular mechanism of Prx Ⅰ regulating ferroptosis in triple negative breast cancer cells,providing a theoretical basis for the study of ferroptosis and a new idea for the treatment of triple negative breast cancer. |
