Evaluation Of Drug Resistance In Neoadjuvant Chemotherapy Of Osteosarcoma And The Relationship Between High Expression Of Skp2 And Drug Resistance

Objective:(1)In this study,we explored a method to evaluate the effect of neoadjuvant chemotherapy by easily available clinical laboratory and imaging indicators.(2)The purpose of this study is to investigate the relationship between Skp2 and neoadjuvant chemotherapy resistance of osteosarcoma by detecting the expression of Skp2 in tumor tissue and paracancerous tissue.Method:Part 1:Collect the clinical data of osteosarcoma patients who were treated in our department from February 2018 to June 2019 according to the standard diagnosis and treatment plan of osteosarcoma,Use the evaluation method developed in this study to evaluate the effect of chemotherapy and check the tumor cell necrosis rate.According to the above data,carry out the diagnostic test and study to explore the feasibility and accuracy of this evaluation method.Part 2:The following operations were carried out according to the drug resistance group and non drug resistance group respectively: 1)q RT-PCR was used to detect the m RNA expression level of Skp2,its upstream signal protein AKT(protein kinase B),substrate(p21,p27,Foxo1),E-cadherin;2)Western blotting was used to detect Skp2,its upstream signal protein Akt,substrate(p21,p27,Fox O1),E-cadherin.Result:Part 1:A total of 17 patients with tumor cell necrosis rate were collected,including 6patients with tumor cell necrosis rate more than 90%.According to the evaluation method,5 patients had poor chemotherapy effect,with diagnostic analysis,Sensitivity(Sen)66.67%;Specificity(Spe)90.91%;Positive likelihood ratio(LR +)= 0.8;Negativelikelihood ratio(LR-)= 0.83;Diagnostic index(DI)157.58%;Youden index(?)=57.58%;CA = 82.35%;AA = 80.23%;Kappa= 0.598.Part 2:Western blotting and q RT-PCR experiments found that the expression of Skp2 in cancer tissues was significantly higher than paracancerous tissues(P<0.05).In the tumor tissue,the expression of p27 and Foxo1 in the drug-resistant group was significantly lower than the non drug resistant group(P<0.05).The expression of E-cadherin in the drug-resistant group was significantly lower than the non drug-resistant group(P<0.05).The expression of Akt in osteosarcoma in the drug-resistant group was significantly higher than non drug-resistant group(P<0.05).Conclusion:Part 1:The evaluation method developed by us has certain advantages and clinical reference value.It can be used as a pretest of later research,but there are still some defects,which need to be further improved and revised.Part 2:Skp2 still plays a role of oncogene in osteosarcoma,and its high expression is closely related to the drug resistance of neoadjuvant chemotherapy of osteosarcoma.The changes of molecular markers of EMT in drug-resistant osteosarcoma may be related to the high expression of Skp2.AKT-Skp2 signaling pathway may play a role in osteosarcoma patients through the regulation of its substrate concentration.Targeted inhibition of Skp2 expression may provide a new treatment strategy for improving the sensitivity of neoadjuvant chemotherapy drugs and improving the 5-year survival rate of osteosarcoma patients.