LNCaP-Rf cells were treated with 1nM of the synthetic androgen R1881 or ethanol vehicle for 4, 16, 48 or 96 hours. Total protein extracts were prepared and equal amounts of protein were analyzed by western blotting using antibodies directed against SRC1, SRC2, SRC3, CBP and p300. To assess potential inter-sample loading differences, blots were stripped and reprobed with an antibody recognizing beta-actin (β-act) (A). RNA was isolated and converted into cDNA. Real time RT-PCR was performed with primers recognizing SRC1, SRC2, SRC3, p300, CBP and PSA (B). mRNA levels were normalized with the values obtained from GAPDH. Values are expressed as relative expression levels, taking the value obtained from one of the untreated samples at the 4 hour time point as 1. Columns, means of values obtained from three independent biological replicates; bars, SEM.