title: Constitutive activity of the androgen receptor.
abstract: Prostate cancer (PCa) is the most frequently diagnosed cancer in the United States. The androgen receptor (AR) signaling axis is central to all stages of PCa pathophysiology and serves as the main target for endocrine-based therapy. The most advanced stage of the disease, castration-resistant prostate cancer (CRPC), is presently incurable and accounts for most PCa mortality. In this chapter, we highlight the mechanisms by which the AR signaling axis can bypass endocrine-targeted therapies and drive progression of CRPC. These mechanisms include alterations in growth factor, cytokine, and inflammatory signaling pathways, altered expression or activity of transcriptional coregulators, AR point mutations, and AR gene amplification leading to AR protein overexpression. Additionally, we will discuss the mechanisms underlying the synthesis of constitutively active AR splice variants (AR-Vs) lacking the COOH-terminal ligand-binding domain, as well as the role and regulation of AR-Vs in supporting therapeutic resistance in CRPC. Finally, we summarize the ongoing development of inhibitors targeting discrete AR functional domains as well as the status of new biomarkers for monitoring the AR signaling axis in patients.
authors.affiliation: Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Siu Chiu
authors.initials: SC
authors.lastname: Chan
authors.affiliation: Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA; Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota, USA. Electronic address: dehm@umn.edu.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Dehm
mesh_terms: D017398:Alternative Splicing / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D005784:Gene Amplification; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D011471:Prostatic Neoplasms / Q000235:genetics; D011944:Receptors, Androgen / Q000737:chemistry / Q000235:genetics*; D015398:Signal Transduction
chemical_list: D011944:Receptors, Androgen
keywords: Androgen receptor; Antiandrogen; CRPC; Castration-resistant prostate cancer; Constitutive activity; LBD; NTD; Prostate cancer; Splice variant