Fig. 6

TSA induces p21 promoter activity via increased Sp1/3-dependent binding to the −100/–81 bp sequence. a Analyses of 5’-deletional p21 promoter-based luciferase (Luc) constructs in LECs. Schematic representation of the respective reporter gene constructs on the right and the relative Luc activities (expressed as % basal activity of the −2325/+8 construct) in graphic format on the left. Black bars, untreated controls (Ctrl.); grey bars, TSA-treated cells (mean ± SE of three independent duplicate assays). *p < 0.05 vs Ctrl. b Representative EMSA using nuclear extracts of untreated (Ethanol only) and TSA-treated (at 400 nM, 1 h) LECs. The DNA-binding activity of Sp1/3 was measured by using nuclear extracts and biotin-labeled DNA probes with or without a competitive cold DNA probe. Supershift experiments were carried out by incubating nuclear extracts with Sp1/3 antibodies. The formation of Sp-dependent binding complexes is indicated by arrows to the left