As a transcriptional regulator, the androgen receptor (AR) regulates the expression of many genes that are essential for male sexual differentiation, including the development of both normal prostate and prostate cancer. The AR acts by binding to regulatory DNA sequences found on the promoters of regulated genes. The study of AR activity on such responsive promoters is greatly facilitated by the use of the reporter gene assay, which provides a quantitative and reproducible method for studying the activity of such promoters. Among the several reporter genes that can be used, the genes encoding luciferase (Luc) and chloramphenicol acetyltransferase (CAT) have been used most widely and successfully by researchers interested in AR-regulated promoters. Such studies have led to the identification and characterization of DNA regulatory elements mediating AR activity on responsive promoters and to an improved understanding of how AR regulates the transcription process. Described in this chapter is a method by which to generate and utilize Luc and CAT reporter gene plasmids driven by the promoter of a novel androgen-regulated gene, ETV1.
