Fig. 4

Suppression of SIRT6 synergistically increases doxorubicin-mediated apoptosis of osteosarcoma cells. a U2OS and KHOS/NP osteosarcoma cells were transfected with control shRNA, shRNA for SIRT6, empty vector, or wild-type SIRT6 and treated with 0.1 µM doxorubicin. Western blots for SIRT6, cleaved PARP1, BCL2, BAX, cleaved caspase 3, and GAPDH were performed. Densitometry analysis of western blots was performed in triplicate and measured by using ImageJ software. b KHOS/NP cells transfected with empty vectors, shRNA for SIRT6, or wild-type SIRT6 were treated with DMSO or 0.1 µM doxorubicin for 24 hours and flow-cytometry analysis performed with staining for propidium iodide and Annexin V. *; P < 0.05, **; P < 0.001