We subsequently assessed the long-term influence of KU0060648 on tumor growth and TMZ sensitivity using anchorage-dependent colony formation assay. Figure 2E elucidated that co-administration of KU0060648 and TMZ substantially reduced colony formation compared with each single agent. Collectively, our data revealed that inhibition of DNA-PKcs by KU0060648 could suppress proliferation and enhance the TMZ cytotoxicity in glioma cells.