In Vitro Reporter Assays for Screening of Chemicals That Disrupt Androgen Signaling

Figure 1

The principle of in vitro androgen transactivation assay, based on stable transfection of a cell line with two plasmids; one encoding the androgen receptor and the other, the androgen response element (ARE) upstream of a reporter (REP) gene such as luciferase. The unstimulated transfected cell expresses both AR and ARE-REP and the AR remains in cytoplasm bound to heat shock proteins (HSP). When the transfected cell is exposed to an androgen such as DHT, the AR moves into the nucleus, dimerizes, binds to ARE, and triggers expression of REP which can be monitored. The reporter gene expression correlates with bioactivity of androgen in the sample. Note: for simplicity only AR monomer binding to ARE has been depicted.