In conclusion, our findings suggest that overactivation of DNA-PKcs is clinically and functionally relevant to the progression of human glioma, and mediates TMZ resistance in glioma treatment. Disrupting the DNA-PKcs/AKT interaction and consequently regulating the downstream effectors of AKT may provide a potential mechanism by which suppression of DNA-PKcs activity can sensitize the response to TMZ and possibly several other chemotherapeutic agents.