Ets-1 transcriptional activity in response to NOS2 expression and NO signaling. (a) Western blot of NOS2 and Ets-1 (thr 38) phosphorylation in MDA-MB-468 cells transfected with control plasmid and NOS2 expression plasmid in the presence of NOS2 substrate (L-Arg) or inhibitor (AG). (b) Western blot of phospho-Ets-1 (thr 38) compared to total Ets-1 in serum-starved cells exposed to either EGF (10 ng/ml) or DETANO. (c) Ets-luciferase activity in MDA-MB-468 cells transfected with either control or NOS2 expression plasmid and cultured in the presence of L-Arg or AG. Data represent mean fold luciferase activity compared to control plasmid incubated with L-Arg. (d) Ets-luciferase activity in serum-starved cells treated with either EGF or DETANO. Data represent mean fold luciferase activity compared to untreated control. Significant luciferase activity (**P < 0.01) was determined by one-way ANOVA from at least three independent experiments. AG, aminoguanidine; ANOVA, analysis of variance; DETANO, diethlylenetriamine NONOate; EGF, epidermal growth factor; Ets-1, erythroblastosis virus E26 oncogene homolog 1; L-Arg, L-arginine; NOS2, nitric oxide synthase.