MP34-16 A NOVEL ANDROGEN RECEPTOR (AR) ANTAGONIST JJ-450 INHIBITS ENZALUTAMIDE-RESISTANT MUTANT AR F876L

You have accessJournal of UrologyProstate Cancer: Advanced (including Drug Therapy) IV (MP34)1 Apr 2019MP34-16 A NOVEL ANDROGEN RECEPTOR (AR) ANTAGONIST JJ-450 INHIBITS ENZALUTAMIDE-RESISTANT MUTANT AR F876L Zeyu Wu*, Zhenyu Yang, Laura Pascal, Keita Takubo, Joel Nelson, Peter Wipf, and Zhou Wang Zeyu Wu*Zeyu Wu* More articles by this author , Zhenyu YangZhenyu Yang More articles by this author , Laura PascalLaura Pascal More articles by this author , Keita TakuboKeita Takubo More articles by this author , Joel NelsonJoel Nelson More articles by this author , Peter WipfPeter Wipf More articles by this author , and Zhou WangZhou Wang More articles by this author View All Author Informationhttps://doi.org/10.1097/01.JU.0000555906.62685.c2AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVES: Prostate cancer (PCa) is the most common cancer and second leading cause of cancer-related deaths in US males. PCa patients treated with androgen deprivation therapy (ADT) will inevitably develop castration-resistant prostate cancer (CRPC). Second generation anti-androgens such as enzalutamide were developed for treating CRPC. However, CRPC can develop resistance to enzalutamide because of androgen receptor (AR) point mutations, AR overexpression, constitutively active AR splice variants, and elevated intratumoral androgen synthesis. For example, AR F876L was reported to be stimulated, instead of inhibited, by enzalutamide, contributing to enzalutamide resistance. New approaches to treat enzalutamide-resistant CRPC are urgently needed. We have recently developed JJ-450 as a novel AR antagonist with potential to treat enzalutamide-resistant CRPC. Objectives: To determine if JJ-450 is capable of inhibiting the function of AR F876L. METHODS: We employed prostate-specific antigen (PSA) enhancer/promoter-based luciferase assay to determine AR transcriptional activity, quantitative real-time polymerase chain reaction (qPCR) assay and western blot to detect expression of AR target genes at mRNA and protein level, fluorescence microscopy to show AR subcellular localization, and 5-bromo-2'-deoxyuridine (BrdU) assay to measure prostate cancer cell proliferation. RESULTS: As expected, enzalutamide inhibited wild-type (wt) AR but not AR F876L transcriptional activity in luciferase assay. In contrast, JJ-450 inhibited both wt-AR and AR F876L transcriptional activity. Also, enzalutamide retarded androgen-induced nuclear import of GFP-AR, but not GFP-AR F876L, whereas JJ-450 retarded nuclear import of both GFP-AR and GFP-AR F876L. To further evaluate JJ-450 inhibition of AR F876L, we stably transfected C4-2 cells with GFP-AR and GFP-AR F876L separately. Enzalutamide inhibited endogenous AR-target gene expression in C4-2-GFP-AR, but not C4-2-GFP-AR F876L subline, whereas JJ-450 inhibited AR-target gene expression in both C4-2 sublines. More importantly, enzalutamide inhibited proliferation of C4-2-GFP-AR, but not the C4-2-GFP-AR F876L subline, whereas JJ-450 inhibited proliferation of both C4-2 sublines. CONCLUSIONS: JJ-450 can inhibit enzalutamide-resistant ARF876L in prostate cancer cells. Source of Funding: This work was funded in part by DOD Award W81XWH-15-PCRP-IA, NIH Grants R01 CA186780 (Z.W.), P50 CA180995 (Z.W.), and R50 CA211242 (L.E.P.) as well as by UPMC Enterprises. This project used the UPMC Hillman Cancer Center Animal Facility which was supported in part by NCI award P30 CA047904. Pittsburgh, PA© 2019 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 201Issue Supplement 4April 2019Page: e501-e502 Advertisement Copyright & Permissions© 2019 by American Urological Association Education and Research, Inc.MetricsAuthor Information Zeyu Wu* More articles by this author Zhenyu Yang More articles by this author Laura Pascal More articles by this author Keita Takubo More articles by this author Joel Nelson More articles by this author Peter Wipf More articles by this author Zhou Wang More articles by this author Expand All Advertisement PDF downloadLoading ...