| Objective: Cervical cancer is the most common gynecological malignant tumor in the clinic,and the morbidity and mortality rate are the fourth among women.Radiation therapy is a common clinical treatment,but radiotherapy resistance has become a major difficulty in clinical treatment.Ubiquitin-specific proteases 53(USP53)is a member of the deubiquitinating enzyme family.USP53 is a family non-protease homologs discovered and named in 2003 by screening the human genome database.It has been shown to be associated with diseases such as human tumors.Damage-specific DNA binding protein 2(DDB2)is a protein involved in nucleotide excision repair(NER),which can repair DNA damage.DDB2 has been shown to interact with USP53 but the specific mechanism of action is not clear.Therefore,this article studies the relationship between USP53 and DDB2 and the mechanism of radiosensitivity in human cervical squamous cell carcinoma after knocking down USP53.Methods1.The tissue and clinical data of 40 patients with cervical squamous cell carcinoma receiving radiotherapy were collected.The expression of USP53 in cervical squamous cell carcinoma was detected by immunohistochemistry.The clinical data were collected for statistical analysis.2.After Si-USP53 transfection,the cells were treated with 0,2,4,6,8,and 10 Gy radiation,and the cell survival rate was calculated by the CCK8 experiment.3.Divide Siha cells into CON group,Si-USP53 group,CON + 8Gy group,and Si-USP53 + 8Gy group.According to the grouping,transfected with Si-USP53 and 8Gy radiation treatment respectively,24 hours after the end of the treatment,the cell cycle distribution and cell apoptosis were detected by flow cytometry.4.24 hours after transfecting cells with Si-USP53,the expressions of USP53 and DDB2 proteins were detected by Western-Blot experiments,and the expressions of USP53 and DDB2 m RNA were detected by Real-Time PCR experiments.5.Divide Siha cells into CON group,Si-USP53 group,CON + 8Gy group,and Si-USP53 + 8Gy group.According to the grouping,transfect of Si-USP53 and 8Gy radiation treatment.The expression of cell cycle related proteins cyclin-dependent kinases 1(CDK1)and cell cycle checkpoint kinase 2(Chk2)was detected by Western-Blot experiment 24 h after the end of treatment.Results1.According to the immunohistochemical results and clinical data of 40 patients,it was found that the expression of USP53 was related to the radiotherapy effect of the patients(P <0.05).2.Successfully knocked down the expression of USP53 in Siha cells,and the proportion of G2 cells in the CON group,Si-USP53 group,CON + 8Gy group,and Si-USP53 +8Gy group increased sequentially.3.After treatment with different doses of 0Gy,2Gy,4Gy,6Gy,8Gy,and 10 Gy,the results of CCK8 testing showed that the survival rate of Si-USP53 group cells was lower.4.In the CON group,Si-USP53 group,CON + 8Gy group,Si-USP53 + 8Gy group,over-flow cytometry detected apoptosis and found no obvious apoptosis between the groups(P> 0.05).5.After Si-USP53 transfection in Siha cells,the m RNA and protein expressions of USP53 and DDB2 in the cells were reduced(P <0.05).6.The expression of DDB2 in the CON + 8Gy group was higher than that of the CON group,and the expression of DDB2 in the Si-USP53 + 8Gy group was higher than that of the Si-USP53 group.7.The protein expression of CDK1 and Chk2 increased after Siha cells received 8Gy radiation treatment.Conclusion1.The positive expression of USP53 in cervical squamous cell carcinoma is related to the therapeutic effect of the patient.2.Knocking down the expression of USP53 and radiotherapy can cause Siha cells to block more in the G2 / M phase.3.Siha cells knocking down the expression of USP53 have lower survival rates when exposed to 0,2,4,6,8,and 10 Gy than the control group.4.Knockdown of USP53 can negatively regulate the expression of DDB2,and reduce DNA damage repair of cells.5.The effect of knockdown of USP53 on cell cycle and radiosensitivity may be caused by CDK1 and Chk2. |
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