DIM reduces the protein levels of cyclin B1 and CDC25C and the activity of CDC2 in HT-29 cells. Cells were treated with different concentrations of DIM as described in Figure 1. (A) Cell lysates were analyzed via Western blotting with the indicated antibodies. Photographs of the chemiluminescent detection of the blots, which were representative of three independent experiments, are shown. (B) CDC2 was immunoprecipitated and analyzed by an in vitro kinase assay, using histone H1 as a substrate. Photographs of an autoradiograph of the dried gel, which are representative of three independent experiments, are provided. The relative abundance of each band to its own β-actin (A) or CDC2 (B) was quantified, and the control levels were set at 100%. The adjusted mean ± SEM (n = 3) of each band is shown above each blot. *Significantly different from 0 μmol/L DIM, P < 0.05.