Effects of Recombinant Disintegrin rAdinbitor on FAK-Ras/MAPK Pathway in C6 Glioma Cells

rAdinbitor was cloned from Gloydius blomhoffi brevicaudus in the laboratory. Previous researches had proved that rAdinbitor could inhibit proliferation of C6 glioma cells as well as promote their apoptosis. The molecular mechanism of rAdinbitor's effects on C6 cells need to be further studied. rAdinbitor was expressed in E. coli BL21/pET23b-adinbitor and purified with Ni Sepharose 6 Fast Flow. The purified protein was confirmed by Western blotting. C6 cells were induced with fibronectin (FN). The effects of rAdinbitor with different concentrations on the expression of FAK, MEK1/2 and Caspase-3 as well as on activity of FAK and ERK1/2 in FN-induced C6 cells were studied by immunoblotting and immunoprecipitation. Results showed that rAdinbitor with different concentrations could obviously reduce the expression of FAK and MEK1/2, increase the expression of Caspase-3, as well as decrease ERK1/2 phosphorylation; besides 10 mg/L rAdinbitor, other concentrations' rAdinbitor could inhibit FAK phosphorylation obviously. All those effects were dose-dependent. Results indicate that the effects of rAdinbitor on decreasing expression and activity of FAK and inhibiting Ras-MAPK signaling pathway play an important role in suppressing the proliferation of C6. Furthermore, the increase in Caspase-3 expression implies that the increase in apoptosis of C6 cells might be due to the suppression of rAdinbitor on the activity of ILK and PI-3K/Akt pathway.