Figure 3

Prolactin-STAT5 induction of a HSP90A promoter-luciferase reporter gene. HeLa cells were transiently cotransfected with DNA encoding the prolactin-receptor, the indicated signal transducers and activators of transcription (STATs), the heat shock protein 90 alpha (HSP90A)-luciferase reporter and β-galactosidase. Luciferase assays were performed 48 hours post transfection and the luciferase activity values normalised with β-galactosidase levels. Fold induction was calculated using the normalised luciferase activity from transfected cells in the absence of prolactin. An asterix indicates that the results are significantly different (p < 0.05 t-test) compared with the sample with no STAT proteins. Each bar represents the average of three to five experiments with standard deviation. (a) STAT5A and/or STAT5B. (b) STAT1 and/or STAT3.