AUTHOR=Abaffy Tatjana, Bain James R., Muehlbauer Michael J., Spasojevic Ivan, Lodha Shweta, Bruguera Elisa, O’Neal Sara K., Kim So Young, Matsunami Hiroaki TITLE=A Testosterone Metabolite 19-Hydroxyandrostenedione Induces Neuroendocrine Trans-Differentiation of Prostate Cancer Cells via an Ectopic Olfactory Receptor JOURNAL=Frontiers in Oncology VOLUME=8 YEAR=2018 URL=https://www.frontiersin.org/articles/10.3389/fonc.2018.00162 DOI=10.3389/fonc.2018.00162 ISSN=2234-943X ABSTRACT=Olfactory receptor OR51E2, also known as a Prostate Specific G-Protein Receptor, is highly expressed in prostate cancer but its function is not well understood. Through in silico and in vitro analyses, we identified 24 agonists and 1 antagonist for this receptor. We detected that agonist 19-hydroxyandrostenedione, a product of the aromatase reaction, is endogenously produced upon receptor activation. We characterized the effects of receptor activation on metabolism using a prostate cancer cell line and demonstrated decreased intracellular anabolic signals and cell viability, induction of cell cycle arrest, and increased expression of neuronal markers. Furthermore, upregulation of neuron-specific enolase by agonist treatment was abolished in OR51E2-KO cells. The results of our study suggest that OR51E2 activation results in neuroendocrine trans-differentiation. These findings reveal a new role for OR51E2 and establish this G-protein coupled receptor as a novel therapeutic target in the treatment of prostate cancer.