Proteomic Research About Ewing’s Sarcoma

Objective:The purpose of the study is to establish the differential protein mass spectrometry of Ewing’s sarcoma(ES)blood and tries to find an effective method to treat ES at the molecular level.In this research,the blood proteomics of Ewing’s sarcoma patients were studied by isotope tags for relative and absolute quantification(iTRAQ)and Western Blotting,and the specific protein molecules related to Ewing’s sarcoma were analyzed,so as to assist in the diagnosis,treatment and prognosis evaluation of the disease.Methods:Step 1: 4 cases of Ewing’s sarcoma met the inclusion with the age from 8-35 years were selected,ranging from January 2016 to January 2019.8 whole blood samples were collected(2 for each patient)from 4 Ewing’s sarcoma patients before chemotherapy,4 whole blood samples from Ewing’s sarcoma patients after chemotherapy,and another 4 whole blood samples from healthy people.The patients in the post chemotherapy group were patients who had undergone VAC/IE for 4 cycles.iTRAQ technique were used to analyze the differential proteins in Ewing sarcoma patients.Step 2: Western Blotting was used for proteomic verification of the screened differential proteins.Step 3: The specificity of the target protein was further verified by observing the serum LDH index,the measured value of tumor meridian,the change of tumor volume and tumor necrosis rate after three-dimensional reconstruction.Results:Part I: By using the iTRAQ technique,we identified 127 differentially expressed proteins based on whole blood samples from Ewing’s sarcoma patients and normal healthy subjects.There were 91 up-regulated proteins and 36 down-regulated proteins.136 differential proteins were identified in total blood samples from Ewing’s sarcoma patients before and after chemotherapy.The number of up-regulated proteins was 101,and the number of down-regulated proteins was 35.Part Ⅱ: Compared with the normal controlled group,the protein expression of COL1α1 and SOD1 in the Ewing sarcoma group before chemotherapy was low,which indicates statistically significance.At the same time,compared with the Ewing’s sarcoma group before chemotherapy,the protein expression of COL1α1 and SOD1 in Ewing’s sarcoma group increased significantly after chemotherapy,and this also shows statistical significance.The expression of COL1α1 and SOD1 has certain specificity in Ewing’s sarcoma.Part Ⅲ: By analyzing the changes of serum LDH index,the measured value of tumor body meridian,the volume of tumor after three-dimensional reconstruction and the tumor necrosis rate before and after chemotherapy for Ewing’s sarcoma,four patients with Ewing’s sarcoma had better therapeutic effect after VAC/IE chemotherapy,which further testified the correlation between the target protein(col1α1 and SOD1)and Ewing’s sarcoma.Conclusion:By using iTRAQ technology to identify the whole blood samples of Ewing’s sarcoma patients,the differential protein expression profile was obtained.The whole blood samples of Ewing’s sarcoma patients were identified by iTRAQ technique,and the differential protein expression profiles was obtained.The specificity of the target protein(COL1α1,SOD1)was further verified by Western Blotting and VAC/IE chemotherapy,which laid a theoretical foundation for the pathogenesis,diagnosis and treatment,dynamic monitoring of disease progression and prognosis evaluation of Ewing’s sarcoma.