Regulation of cortactin with Rac1 activation in migration and invasion of U251 glioma cells / 中华神经医学杂志

ABSTRACT

Objective To investigate the role of cortactin in migration and invasion of U251 glioma cells and role of Rac1 activation in this process.Methods Human glioma U251 cells were cultured in vitro.The expressions and distributions of Rac1 and cortactin in U251 glioma cells were detected by immunofluorescence.U251 glioma cells assigned into 4 treatment groups:siRNA-cortactin group (transfected by siRNA specific cortactin),siRNA-NC group (transfected by negative control RNA sequence),siRNA-N group (transfected by empty vector) and siRNA-cortactin+Rac1 group (transfected by siRNA specific cortactin and Rac1 inhibitor).Forty-eighty h after grouping and each treatment,the protein expressions of cortactin and Rac1 in the 4 groups were detected by Western blotting;the migration and invasion of glioma cells were evaluated by wound-healing and Transwell-chamber invasion assays;the lamellipodia of glioma cells was observed by immunofluorescence.Results Cortactin and Rac1 were co-localized in the front ofglioma cells,where actin was polymerized and lamellipodia was formed.As compared with siRNA-NC group and siRNA-N group,siRNA-cortactin group and siRNA-cortactin+Rac1 group had significantly lower cortactin and Rac1 expressions (P＜0.05);siRNA-cortactin+Rac1 group had significantly lower cortactin and Rac1 expressions as compared with siRNA-cortactin group (P＜0.05).As compared with siRNA-NC group and siRNA-N group,siRNA-cortactin group and siRNA-cortactin+Rac1 group had significantly smaller healing areas and number of perforator cells (P＜0.05);siRNA-cortactin+Rac1 group had significantly smaller healing areas and number of perforator cells as compared with siRNA-cortactin group (P＜0.05).As compared with siRNA-NC group and siRNA-N group,siRNA-cortactin group and siRNA-cortactin+Rac1 group had decreased lamellipodia of glioma cells;siRNA-cortactin+Rac1 group had decreased lamellipodia of glioma cells as compared with siRNA-cortactin group.Conclusion Cortactin can promote the migration and invasion of glioma cells by regulating lamellipodia formation;combined inhibition of Rac 1 and cortactin may be an effective mean for treatment ofglioma.