Breast cancer susceptibility gene 1 (BRCA1) is a coactivator of the androgen receptor

In the present study, the role of BRCA1 in Ligand-dependent androgen recept or (AR) signaling was assessed, In transfected prostate and breast cancer c ell lines, BRCA1 enhanced AR-dependent transactivation of a probasin-derive d reporter gene. The effects of BRCA1 were mediated through the NH2-termina l activation function (AF-I) of the receptor, Cotransfection of p160 coacti vators markedly potentiated BRCB1-mediated enhancement of AR signaling, In addition, BRCA1 was shown to interact physically with both the AR and the p 160 coactivator, glucacorticoid receptor interacting protein 1. These findi ngs suggest that BRCA1 may directly modulate BR signaling and, therefore, m ay have implications regarding the proliferation of normal and malignant an drogen-regulated tissues.