Figure 6

p21 knock-down via siRNA abrogates growth inhibition of Androgen Receptor In Breast Epithelium (ARIBE) cells. (A) ARIBE cells were transfected with p21 siRNA constructs, control siRNA, or no siRNA, and incubated for 24 hours. After incubation, whole-cell lysates were probed for expression of p21, and GAPDH was used as a loading control. (B) ARIBE cells transfected for 24 hours with p21 or control siRNA were subsequently treated with vehicle or 1 nmol/l R1881 for 4 days, and cells were counted. The ratio of growth between vehicle and R1881-treated cells was calculated and normalized to untransfected (no siRNA) values to determine the fold increase in growth of siRNA-transfected cells. Error bars represent the standard deviation of the mean of three independent counts. The growth difference between cells transfected with p21 siRNA constructs and mock siRNA was significant by one-way analysis of variance (*P < 0.05).