Figure 1.

Importance of coregulator expression for androgen responsiveness of AR target genes. LNCaP cells were transfected with siRNAs targeting coregulators or nonspecific control siRNAs (c). Forty-two hours after transfection, cells were treated with 5 nm R1881 or ethanol vehicle. Forty-eight hours later, androgen responsiveness of expression of ARE-driven genes that are up-regulated [(+), PSA, KLK2, TMPRSS2 and SCAP] or down-regulated [(−), maspin and fibronectin-1 (FN1)] after androgen exposure was evaluated by real-time RT-PCR. AR target gene mRNA levels were normalized with the values obtained from glyceraldehyde-3-phosphate dehydrogenase expression and are expressed as relative expression values, taking the value obtained from one of the vehicle-treated control transfected conditions as 1. Values represent relative fold induction of mRNA expression after R1881 treatment and correspond to the means of values obtained from biological triplicate samples. The heatmap representing the results was generated using R. Full (100%) androgen induction of AR target gene expression obtained in cells transfected with nontargeting control (c) siRNA is represented by orange. Yellow and white indicate an increase (>100%) in androgen responsiveness; red represents decreases (<100%) in androgen-responsiveness of AR target genes upon loss of a specific coregulator. Right, Scale numerically matching color shades with extent of the androgen regulation of AR target gene expression. MAGE, MAGEA11. SRC1, SRC2, and SRC3 correspond to DASL nomenclature NCOA1, NCOA2 and NCOA3 in Tables 1–3.