Effect of Raptor on invasion ability of glioma cells

AIM：To study the influence of Raptor on the invasion ability of glioma cells. METHODS：The technique of RNA interference was used. U87 cells were transfected with Raptor restricted siRNA plasmid, and the expression level of Raptor in the transfected cells was detected by Western blotting. The invasive ability of the cancer cells in vitro was determined. The phosphorylation level of ARK5 and the expression of MMP-2 and MMP-9 were detected by Western blotting. The expression levels of Raptor in the tumor samples of low-grade gliomas (WTO grade I and grade II) and high-grade gliomas (WTO grade III and grade IV) were also analyzed by immunohistochemical staining. RESULTS：Raptor siRNA was transfected into U87 cells and the cells were named siRaptor/U87 cells. The cells transfected with the control plasmid was named Scr/U87 cells. The expression level of Raptor in siRaptor/U87 cells was lower than that in Scr/U87 cells. The results of in vitro invasion assay showed that the number of siRaptor/U87 cells penetrating the Matrivgel matrix membrane was less than that of Scr/U87 cells (P＜0.01). The protein expression of MMP-2 and MMP-9, and phosphorylation of ARK5 protein in the cells in the experimental group were lower than those in control group. The correlation between the expression of Raptor in gliomas and the degree of deterioration was also observed (P＜0.01). CONCLUSION：The expression of Raptor may contribute to the invasion ability of glioma cells by phosphorylation of ARK5 and increase in the levels of MMP-2 and MMP-9.