RNA interference suppression of Nogo-66 receptor prevents Nogo-66-mediated inhibition of invasion and adhesion and simultaneously increases cell apoptosis in C6 cells

摘要

Gliomas are the most common primary tumors of the central nervous system (CNS). Nogo-66 is an extracellular domain of Nogo-A, which can block axon regeneration in the CNS after trauma. Some studies have indicated that Nogo-A and its receptor (NgR) are expressed in tumor tissues; however, their roles in tumors are still unknown. We report the impact of Nogo-66 and NgR on the proliferation, apoptosis, adhesion and invasion of C6 glioma cells. Short hairpin RNA (shRNA)-triggered RNA interference was used to inhibit NgR expression in C6 cells. Then, an in vitro cell adhesion assay was performed to assess the effect of NgR downregulation on the adhesion ability of C6 cells. In addition, a chamber assay and a cell scratch assay were conducted to test invasion ability. The spontaneous apoptosis of C6 cells was examined by flow cytometry, western blotting and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. NgR downregulation resulted in a significant increase of C6 adhesion and invasion activity in the presence of Nogo-66, markedly inhibited proliferation and induced spontaneous apoptosis. In conclusion, knockdown of NgR enhanced invasion and adhesion but increased cell apoptosis in C6 cells, suggesting that Nogo-66/NgR might have complex effects on glioma cells.