Analysis of androgen receptor activity by reporter gene assays

Androgen receptor (AR) acts as a ligand-regulated transcription factor that conveys the message of both natural and synthetic androgens directly to the level of gene programs. Reporter gene assays provide a convenient and quantitative way to measure the transcriptional activity of AR and the functionality of its binding sites (AREs) in DNA. Many reporter genes and different transfection methods can be used for this purpose. In this chapter, we describe the use of firefly luciferase gene-based reporters and transfection protocols for the measurement of AR activity in heterologous COS-1 cells cotransfected with an AR expression vector and in VCaP prostate cancer cells expressing endogenous AR. We also discuss the suitability of different reporter constructs and transfection methods for different cell types and how reporter gene assays can be employed to complement chromatin immunoprecipitation assays.