Fig. 3. Time course for the effect of 15d-PGJ2 on cyclin D1 expression. A, MCF-7 cells were treated with 10 µM 15d-PGJ2 for the indicated times, and cyclin D1 and ß-actin protein levels were determined by Western blotting. B, quantitative analysis of the cyclin D1 Western blot was performed using a laser densitometer. Error brackets, SE for three determinations (0 time point) or the range for two determinations (all other time points).