Study On The Experimental Anti-osteosarcoma Effect And Mechanism Of Dihydroartemisinin Combined With Iron Preparation Based On Iron Metabolism

Iron is one of essential metal elements for human body,which participates in many life processes such as cell proliferation,energy metabolism and cell death.The abnormal activity of iron metabolism is an important feature of malignant tumor,which is characterized by increased cellular iron uptake,decreased iron excretion and increased iron content in labile iron pool.Iron in labile iron pool participates in Fenton reaction to produce reactive oxygen species,which leads to the increase of oxidation level in tumor cells.The inactivation of glutathione peroxidase 4(GPX4)can increase the level of iron mediated lipid ROS and induce ferroptosis in tumor cells.Previous studies in our group have shown that iron metabolism is closely related to bone metabolism.Osteosarcoma is the most common malignant tumor in the skeletal system.However,the relationship between its clinical characteristics and iron metabolism needs to be studied.Dihydroartemisinin,a classical antimalarial drug,relies on iron to release peroxides to cause death of Plasmodium falciparum.At the same time,a large number of studies have shown that dihydroartemisinin has a strong anti-tumor effect.However,the effect of dihydroartemisinin on osteosarcoma and the specific mechanism are only a few reports,and the effect of dihydroartemisinin on iron metabolism of osteosarcoma needs further study.In this study,the relationship between iron metabolism and clinical characteristics of bone tumor patients,such as survival time,disease recurrence rate,bone tumor stage and metastasis,were studied by using large database and bioinformatics analysis method,the correlation between the expression of iron and iron metabolism related proteins and tumor stage was studied by analyzing the iron metabolism related proteins’ expression of clinical human osteosarcoma samples;the possible targets of dihydroartemisinin were studied by molecular docking and GO analysis;combined with cell biology,molecular biology and pharmacology,the effects of dihydroartemisinin combined with iron preparation on iron metabolism of osteosarcoma cells and its anti-osteosarcoma effect and mechanism were studied.The results of cell experiment showed that dihydroartemisinin inhibited the activity and proliferation of human osteosarcoma cells and induced autophagy,apoptosis and ferroptosis;dihydroartemisinin induced mitochondrial damage,lysosomal membrane permeability,ferritinophagy and increased iron content in labile iron pool and promoted the total ROS level,lysosomal ROS level and lipid ROS level.Also,dihydroartemisinin activates MAPKs signaling pathway.These results suggest that dihydroartemisinin has anti-osteosarcoma effect by affecting iron metabolism and increasing ROS level.Dihydroartemisinin combined with iron preparation can increase iron content in labile iron pool of tumor cells,increase ROS level,promote ferroptosis of tumor cells,and play a combined anti-osteosarcoma effect.The results of animal experiments showed that dihydroartemisinin significantly inhibited tumor growth and tumor weight,promoted tumor iron death,and played an anti-osteosarcoma effect.Iron dextran can promote the anti-osteosarcoma effect of dihydroartemisinin,promote the inhibition of dihydroartemisinin on tumor growth and tumor weight in xenograft tumor mice,and promote the ferroptosis of osteosarcoma induced by dihydroartemisinin.In conclusion,iron metabolism is closely related to the prognosis and clinical features of osteosarcoma.The higher the malignant degree of tumor,the more active iron metabolism.Dihydroartemisinin induces ferritinophagy,increases iron content in labile iron pool,increases ROS level in tumor cells,activats MAPKs signaling pathway,induces autophagy upstream initiation,lysosomal membrane permeability,autophagy flux block,and mitochondrial damage leading multiple cell death like ferroptosis and apoptosis.Iron preparation can promote the ferroptosis of human osteosarcoma cells and play a combined anti-osteosarcoma effect by promoting the increase of iron content in the labile iron pool of cells,the increase of ROS level caused by dihydroartemisinin,and the increase of lysosomal membrane permeability and lipid ROS level.These will help to understand the effect and mechanism of dihydroartemisinin and iron preparation on osteosarcoma,and provide theoretical basis for clinical treatment of osteosarcoma.