Propofol inhibits invasion and proliferation of C6 glioma cells by regulating the Ca2+ permeable AMPA receptor-system xc− pathway

Anesthetics are documented to affect tumors; therefore, we studied the antiglioma effect of propofol on proliferation and invasiveness of glioma cells and explored the underlying mechanism. C6 glioma cells were cultured and treated with propofol, and cell viability, invasiveness, and migration were measured. Glutamate release was measured using an enzyme-catalyzed kinetic reaction. xCT protein and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor GluR2 subunit protein expression was assessed with Western blot analysis and immunofluorescent staining. We observed that propofol significantly inhibited C6 glioma cell viability, invasiveness, and migration and decreased glutamate release. An agonist of the cystine/glutamate antiporter system (system xc−), N-acetylcysteine (NAC), reversed propofol's effects, and propofol could inhibit C6 glioma cell proliferation by adding excess exogenous glutamate (100 μM). Finally, propofol increased the surface expression of GluR2, but decreased surface expression of xCT. The effects of propofol on surface expression of GluR2 and xCT could be rescued by (R, S)-AMPA, an agonist of Ca2+ permeable AMPA receptor (CPAR). Thus, propofol can inhibit cell viability, invasiveness, and migration of C6 glioma cells, and the CPAR-system xc− pathway contributes to these events.