The Effects Of β-elemene In Combination With IGF1 Receptor Inhibitor On Ewing’s Sarcoma Cells And The Mechanism

Background: Ewing,s sarcoma(ES)is a class of highly malignant hyperplastic tumor,occuring in young people.In recent years,with the development of the study,the limitations of the treatment of Ewing,s sarcoma has been significantly improved,but the occurrence of metastasis and local recurrence of patients still need new treatment.At present,targeted therapy could provide hopes to a variety of tumors,especially in advanced cancer patients.Insulin-like growth factor 1 receptor(IGF1R)plays an important role in the pathogenesis of Ewing’s sarcoma and is considered to be a therapeutic target,and targeting IGF1 R has been undergoing clinical trials for Ewing’s sarcoma and is found to be effective in some patients.Unfortunately,resistance and relapse have become bottlenecks for the development of targeting IGF1 R in Ewing’s sarcoma.It is possible to use the treatment of targeting IGF1 R in Ewing’s sarcoma by improving the efficiency of IGF1 R inhibitors and antibodies,and reducing the resistance and relapse.Over past centuries,natural products have played a key role in drug discovery and development.They provided the basis and inspiration for developing effective therapeutics for human disease.β-elemene is a compound extracted from Curcuma phaeocaulis,has been used as an anticancer drug in China for many years,which has little cytotoxic effect on many tumors and has little side effects.The main biological functions are: mitigation of tumor cell mitosis,inhibition of tumor cell proliferation,induction of tumor cell apoptosis.However,the effect of β-elemene on Ewing’s sarcoma,or the role of IGF1-induced cell proliferation,has not been reported.In this study,we combine β-elemene with IGF1 R inhibitors at ineffective doses to treat Ewing’s sarcoma cells,and to investigate that whether β-elemene can enhance the cytotoxicity of IGF1 R inhibitors,and possibilities of the combination of two drugs in future.We will clarify the molecular mechanism of action by studying the action of apoptosis and autophagy related pathways.This research is expected to provide new clues for the treatment of Ewing’s sarcoma.Methods: The effects of β-elemene on the proliferation of Ewing’s sarcoma cells induced by IGF1 were observed by in vitro cytotoxicity assay using two strains of Ewing’s sarcoma cell lines(A673 and MHH-ES1),with β-elemene and IGF1.The effect of combination of β-elemene and IGF1 R inhibitor on the proliferation of Ewing’s sarcoma cells was observed by in vitro cytotoxicity assay.The activity of apoptosis、autophagy and PI3K-Akt-m TOR signaling pathway was detected by immunoblotting.Results: 1.IGF1 treatment induced A673 cell proliferation,while the cell proliferation was inhibited treated with β-elemene,in a concentration and time-dependent manner.The same results were obtained in MHH-ES1 cells.2.The proliferation of A673 and MHH-ES1 were significantly inhibited by the combination of β-elemene and IGF1 R inhibitor(PPP and NVP-AEW541)in Ewing’s sarcoma cells,and the inhibitory effect was more effective than that of β-elemene only.3.The phosphorylation of Akt,PRAS40 and S6 was significantly inhibited by the combination of β-elemene and ineffective IGF1 R inhibitor(PPP)in the treatment of A673,and the level of PARP activation was increased,and the transformation of LC3I-II was evident and Atg7 Expression level was downregulated.Conclusion: β-elemene has a significant inhibitory effect on IGF1-induced proliferation of Ewing’s sarcoma cells.Combination of β-elemene and IGF1 R inhibitors can significantly improve the effect of IGF1 R inhibitors or β-elemene.The combination of β-elemeneand IGF1 R inhibitors can inhibit PI3K-Akt-m TOR signaling pathway activity,induce the activation of apoptosis and autophagy related molecules.This research is expected to provide new ideas for the treatment of Ewing,s sarcoma.