The Expression Of OTUB1 In Human Gliomas And Its Correlation With Glioma Cells Migration

Objective:To investigate the expression of OTUB1 in human gliomas and its relationship with the prognosis of glioma patients,then further explore the effect and possible mechanism of OTUB1 in glioma cells migration.Methods:(1)First,the expression of OTUB1 and epithelial marker protein E-cadherin in normal brain tissues and glioma tissues was detected by Western blot analysis.Then immunohistochemical method was used to measure the expression of OTUB1 and E-cadherin in paraffin sections of 89 cases of glioma,and their correlation was analyzed by statistical methods.After that,we collected the clinical data of corresponding glioma patients,and analyzed the relationship between OTUB1 expression and the clinicopathological characteristics in patients with glioma by Pearson chi-square test.In addition,we constructed the Kaplan-Meier survival curve and compared the effect of OUTB1 expression on the survival rate of patients with different pathological grade gliomas by Log-rank test.(2)Selection of glioma cell lines with high expression of OUTB1 as the experimental object(U87MG),and then constructed a stable silencing of OTUB1 cell model in vitro by using RNA interference technology.The effects of OTUB1 on the migration of glioma cells were investigated by Wound healing assay and Transwell migration assay.(3)By using Western blot analysis,we examined the effect of gene silencing of OTUB1 on the expression of epithelial-mesenchymal transition markers E-cadherin,vimentin,snail as well as extracellular matrix degrading protease MMP2 and MMP9,and then explored the possible mechanism of OTUB1 on glioma cells migration.Results:(1)Western blot and immunohistochemistry results displayed that OTUB1 was overexpressed in glioma tissues,and its expression level showed an increasing trend from low-grade glioma tissues to high-grade glioma tissues.The expression of E-cadherin was opposite to OTUB1,and their correlation analysis showed a negative correlation(r=-0.469,P<0.01).In addition,statistical analysis indicated that there was a statistical significance between OTUB1 expression level and the pathological grade of glioma(P=0.005).Kaplan-Meier survival analysis at different grades of glioma patients demonstrated that patients with high expression of OTUB1 had shorter survival time(P<0.05).(2)Wound healing assay and Transwell migration assay demonstrated that silencing of OTUB1 would inhibit glioma cells migration.Western blot analysis showed that inhibition of OTUB1 expression could increase the expression of E-cadherin and decrease the expression of vimentin,snail,MMP2 and MMP9,which meant OTUB1 was associated with the epithelial-mesenchymal transition and extracellular matrix degradation of glioma cells.Conclusions:(1)In human gliomas,OTUB1 expression level was positively correlated with the pathological grade of glioma,and it could also affect the prognosis of patients with glioma.Patients with high expression of OTUB1 had more poorly prognosis.(2)Interference of OTUB1 expression can significantly weaken the migration ability of glioma cells.(3)Silencing of OTUB1 resulted in a decrease expression of mesenchymal markers Vimentin and Snail,while increase the expression of epithelial marker protein E-cadherin.Besides,it could also inhibit matrix metalloproteinase 2 and matrix metalloproteinase 9 expressions.Therefore,OTUB1 could promote epithelial mesenchymal transition and extracellular matrix degradation,which may be an important mechanism for it to promote glioma cells migration.