Figure 5

Upregulation of p21 expression upon androgen receptor (AR) ligand binding in the presence of mitogen-activated protein kinase (MAPK)signaling. (A) Control cells (MCF-10A and 10A plus vector) and ARIBE cells were cultured in normal propagation media (with 20 ng/ml EGF) and treated with either vehicle or 1 nmol/l R1881 for 24 hours. Whole-cell lysates were probed for expression of p21 and GAPDH for a loading control. (B) Control cells (MDA-MB-231 and 231 plus vector) and MDA-MB-231 cells expressing AR (ARc3 and ARc4) were cultured in the presence EGF and treated with either vehicle or 1 nmol/l R1881 for 24 hours. Whole-cell lysates were probed for expression of p21 and GAPDH was used as loading control.