| Objective:To investigate the expression patterns of syndecan-1 and syntenin in glioma and their effects on glioma cell migration.Methods:The expression,subcellular location and correlation of syndecan-1 and syntenin were detected by immunohistochemical technology in glioma tissues with different grades;The effciency of syndecan-1 overexpression and knockdown was identified by western blot assay;the protein levels of syntenin after overexpression and knockdown of syndecan-1 were detected by western blot assay;the u251 cell migration after overexpression and knockdown of syndecan-1 were evaluated by transwell migration assays and wound healing assays;The effects of syndecan-1 overexpression and knockdown on Rac1 activity were assessed by Rac1 Pull-Down and western blot assays.Results : Immunohistochemical assay showed that the expression of syndecan-1 and syntenin were consistently higher in high-grade glioma than low-grade or normal brain tissues(H=12.784,P=0.002;H=16.274,P=0.000);both syndecan-1 and syntenin staining density were shown to be positively correlated with glioma tumor grade(rs=0.576,P=0.001;rs=0.661,P=0.000).Meanwhile,the expression levels of syndecan-1 were positively correlated with those of syntenin in glioma tissues(rs=0.628,P=0.001).Western blot analysis showed that syndecan-1 and syntenin were both upregulated in u251 cells with syndecan-1 overexpression(F=83.216,P=0.000;F=15.571,P=0.004),while consistenly decreased with syndecan-1 knockdown when compared with either negative group or control group(F=60.728,P=0.000;F=16.747,P=0.004).Transwell assay showed that syndecan-1 overexpression significantly enhanced u251 cell migration than that of vector group and control group(F=95.559,P=0.000),while syndecan-1 knockdown decreased(F=111.391,P=0.000).Wound-Healing assay showed that u251 cells wound closure with syndecan-1 overexpression was higher than that of vector group and control group(F=69.89,P=0.000),while the wound closure with syndecan-1 knockdown was lower than that of negative group and control group(F=50.819,P=0.000).Western blot showed that the expression of activated-Rac1 was significantly increased in u251 cells with syndecan-1 overexpression than vector group and control group(F=12.37,P=0.007),while decreased in u251 cells with syndecan-1 knockdown(F=13.082,P=0.006),The protein expression of total Rac1 was no significantly difference when compared to vector(P>0.05).Conclusion:(1): The expression of syndecan-1 and syntenin were both higher in glioma tissues with high grade,while weak or less in normal brain tissues,moreover,the expression of syndecan-1 was positively correlated with syntenin in glioma tissues.(2): syndecan-1 mediated syntenin upregulation promotes glioma cell migration via Rac1 activation pathway. |
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