E-cadherin knock-down increases the proliferation of human PCA PC3 cells. (A) Multiplication rate of Sh-PC3 and ShEC-PC3 cells was determined by MTT assay. Data shown is mean ± SD of 12 samples. (B) Clone formation by Sh-PC3 and ShEC-PC3 cells was examined in a clonogenic assay as detailed in the methods. Number of clones with more than 50 cells were counted and presented in a bar diagram. Data shown is mean ± SD of 6 samples. (C-D) Sh-PC3 and ShEC-PC3 cells were injected subcutaneously in athymic nude mice, and average tumor volume (mean ± SEM) as a function of time is presented. Tumor tissues were analyzed for proliferation biomarkers (PCNA and Ki-67) by IHC. Percentage of PCNA and Ki-67 positive cells was calculated by counting the number of positive stained cells (brown stained) and the total number of cells at five arbitrarily selected fields from each tumor at 400x magnification. The data shown in the bar diagrams is the mean±SEM of 7–10 samples. *, p ≤ 0.001; #, p ≤ 0.01; $, p ≤ 0.05.