Multiplexed Promoter-dependent Screen for Selective Androgen Receptor Modulators.

摘要

The androgen signaling pathway remains a key therapeutic target for prostate cancer. Despite recent advances in treatment, disease invariably recurs. Genes regulated by androgen receptor (AR) in recurrent prostate cancer differ from those in normal cells or early disease. A novel goal is to inhibit AR target genes involved in cancer growth but retain expression of genes for normal cell survival. These gene sets may differ in androgen response element (ARE) signatures. AREs include consensus inverted repeats (cARE) shared amongst receptors and more selective direct repeats (sAREs). Genes involved in differentiation appear to rely more on sAREs than genes driving proliferation. ARE preference can vary with ligand, cofactor interactions or AR mutation. Thus compounds altering receptor conformation via any domain may influence promoter choice. To identify such compounds, we developed a multiplexed assay for differential AR action in transfected cells using fluorescent reporters driven by multimerized cAREs, sAREs or a PSA promoter. We performed a high-throughput screen of a library of FDA-approved drugs, seeking candidates that suppressed cARE but not sARE reporters, and are currently narrowing hit compounds for validation. This promoter-dependent screen may identify compounds that elicit differential gene expression and lead to drugs generating fewer side effects and less resistance.