FIG. 1.

Selective modulation of E2F1 apoptotic target genes by hSirT1. (a) U2Os cells were transfected with the indicated reporter constructs and either the E2F1 or the hSirT1 expression vector. Luciferase activity, expressed as induction over the control, was normalized for transfection efficiency using the dual-luciferase assay system. Histograms show the means of data for three experiments, each performed in quadruplicate; bars indicate standard deviations. (Right) Exogenously expressed E2F1 and hSirt1 are detected by anti-HA (α-HA) and anti-FLAG immunoblotting (IB), respectively. (b) RNAs from SaOs2 cells exposed for 24 h to TSA (100 nm) or NAM (25 mM) were analyzed with primers specific for TAp73, caspase 7, and Bim transcripts by PCR. Results are expressed as arbitrary units compared to the normalized basal level of expression of each gene in untreated cells. (c, top) Chromatin from asynchronously growing U2Os cells was immunoprecipitated with either the relevant control IgG or the indicated antibodies and analyzed with primers amplifying the region containing E2F sites in P1p73, Bim, and caspase 7 by PCR. (Bottom) Control reactions using distant primers (C) did not amplify anti-E2F1 and hSirT1 ChIP products.