The Inhibitory Effects of a Monoclonal Antibody Targeting Neuropilin-1 on Adhesion of Glioma Cells to Fibronectin

We investigated the inhibitory effects of anti-Neuropilin-1 monoclonal antibody (NRP-1 MAb) on adhesion of glioma cells to Fibronectin (FN) and the associated mechanisms. The effects of NRP-1 MAb on adhesion of U251 glioma cells and formation of stress fibers were studied using adhesion assays and confocal fluorescence microscopy. After treatment of U251 glioma cells with NRP-1 MAb, changes of related proteins adhering to FN were detected by co-immunoprecipitation and Western blot. Adhesion assays showed that NRP-1 MAb played an inhibitory role in adhesion of U251 glioma cells. Confocal fluorescence microscopy, co-immunoprecipitation and Western blot showed that NRP-1 MAb can inhibit the formation of stress fibers adhering to U251 cells. NRP-1 MAb can also affect the formation of Integrin alpha 5 beta 1-NRP-1 complex, and also reduce the level of phosphorylation of FAK and p130cas. In conclusion, NRP-1 MAb has the inhibitory effects on adhesion of glioma cells to FN. This effect is related to the inhibition of NRP-1 MAb on the formation of Integrin alpha 5 beta 1-NRP-1 complex, which leads to the inhibition of FAK/p130cas signaling pathway.