Figure 7.
Enhanced Sirtuin activity sensitizes cells to TNFα-induced apoptosis. (A) Western blot analysis demonstrates the expression of SIRT1 in HEK 293: vector control (pCMV), and cells overexpressing SIRT1 or SIRT(HY). Cells were treated with TNFα (100 ng/ml) for 4 h, followed by nucleosome and caspase-3 assays. (B, C) NSCLC cells were pretreated with resveratrol (10–50 μM) for 1 h before the addition of TNFα (100 ng/ml) for 4 h. Both nucleosome and caspase-3 assays were performed in triplicate in three independent experiments. (D) Western blot analysis of H1299 cells transfected with either control or SIRT1 siRNAs demonstrated complete knockdown of the SIRT1 protein. The nonspecific (NS) protein and β-tubulin are shown as loading controls. For RPAs, cells were treated with resveratrol (50 μM) overnight, followed by TNF treatment for 1 h. For nucleosome assay, treatment conditions were the same as in (B).