Fig. 7
Co-treatment of ATM inhibitor KU-55,933 or the PARP inhibitor olaparib with doxorubicin synergistically inhibited the proliferation of SIRT6-overexpressing U2OS and KHOS/NP osteosarcoma cells. a U2OS and KHOS/NP cells transfected with empty vector or wild type-SIRT6 were treated with DMSO, 10 µM KU-55,933, 0.1 µM doxorubicin, or 0.1 µM doxorubicin and 10 µM KU-55,933. BrdU proliferation assay was performed by seeding of 0.8 × 103 U2OS cells and 0.8 × 103 KHOS/NP cells, and absorbance measured 24 hours after seeding. Colony-forming assay was performed by seeding U2OS cells (2 × 103) and KHOS/NP cells (2 × 103) in 24-well culture plates. b U2OS and KHOS/NP cells transfected with empty vector or wild type-SIRT6 were treated with DMSO, 30 µM olaparib, 0.1 µM doxorubicin, or 0.1 µM doxorubicin and 30 µM olaparib. The BrdU proliferation assay was performed by seeding of 0.8 × 103 U2OS cells and 0.8 × 103 KHOS/NP cells, and the absorbance measured 24 hours after seeding. Colony-forming assays were performed by seeding U2OS cells (2 × 103) and KHOS/NP cells (2 × 103) in 24-well culture plates. *; P < 0.05, **; P < 0.001