Experimental research of IKKε through E-cadherin regulation of the human brain glioma migration and invasion ability

Abstract

Objective To investigate the effect of IKKe in glioma cells on the regulation of E-cadherin expression and cell migration and invasion ability. Methods The IKKe overexpression vectors and shRNA-IKKe lentivirus were constructed. The TP483 glioma cell lines were transfected by the IKKe overexpression plasmid. The expression level of IKKe in glioma cells was upregulated. The U251 and U138 glioma cell lines were transfected by the shRNA-IKKe lentivirus, IKKe expression level in glioma cells was downregulated. The expression levels of IKKe and E-cadherin in cells were detected by RT-PCR and Western blot. The expression changes of IKKe and E-cadherin after transfecting were observed by using the immunofluorescence assay. The cell migration and invasion abilities were detected by using the scratch test and Transwell assay. Results Compared with the non-transfected group (TP483 control group), the expression level of IKKe protein increased (P=0.000), and the expression level of E-cadherin protein decreased (P=0.000) in the transfected IKKe expression plasmid group (TP483 treaed group). In the glioma cells transfected IKKe shRNA(the U251 treated group and the U138 treated group) , the expression level of IKKe protein decreased significantly compared with the non-transfected group (the U251 treated group and the U138 treated group; all P<0.05). At the same time, the expression levels of E-cadherin protein in each treated group were all increased compared with the control group (P<0.05). The scratch repair rate of the TP483 treated group was higher than that of the control group (56.39±0.93% vs. 46.43±1.68%; P=0.035). After transfection of overexpression plasmid for 24 h, the number of TP483 cells passing through the filter membrane increased compared with the control group (55.8±6.0 vs. 24.6±2.3; P=0.000). The scratch repair rates of the U251 and U138 treated groups decreased compared with their respective control groups (the U251 treated group: 50.40±1.09%, the U251 control group: 87.29±11.11%, P=0.043; the U138 treated group: 48.20±1.34%, the U138 control group: 73.15±6.62%, P=0.035); After transfection for 24 h, the number of cells passing through the filter membrane decreased in the U251 and the U138 groups compared with the control group (the U251 treated group: 77.8±6.4, the control group: 124.0±13.4, P=0.000; the U138 treated group: 25.8±4.2, the control group: 54.8±7.1, P=0.000). Conclusions The low expression of IKKe can effectively inhibit the invasion and migration of glioma cells, and the high expression of IKKe can enhance their invasion and migration abilities. Its possible mechanism is to influence the invasion and migration abilities of glioma cells through regulating the expression level of E-cadherin. Key words: Glioma; Transcellular cell migration; Neoplasm invasiveness; Ⅰ-kappa B kinase; E-cadherin