Androgen depletion and high cell density both induce cell cycle arrest in LNCaP and LAPC-4 cells. A, Analysis of changes in cell cycle distribution in response to high cell density (FBS) and androgen depletion (CS). The data represent means ± SD of three independent experiments. “*”denotes statistical significance compared with control (2 days in FBS), “#” denotes statistical significance compared with 2 days in CS. B, Western blot analysis of the expression of selected cell cycle regulators in LNCaP and LAPC-4 cells. Graphs represent optical density (O.D.) of p-Cdk2 normalized to O.D. of total Cdk2.