title: Enzalutamide inhibits androgen receptor-positive bladder cancer cell growth.
abstract: Emerging preclinical evidence suggests that androgen-mediated androgen receptor (AR) signals promote bladder cancer progression. However, little is known about the efficacy of an AR signaling inhibitor, enzalutamide, in the growth of bladder cancer cells. In this study, we compared the effects of enzalutamide and 2 other classic antiandrogens, flutamide and bicalutamide, on androgen-induced bladder cancer cell proliferation, migration, and invasion as well as tumor growth in vivo.
  
  
  
  Thiazolyl blue cell viability assay, flow cytometry, scratch wound-healing assay, transwell invasion assay, real-time polymerase chain reaction, and reporter gene assay were performed in AR-positive (e.g., UMUC3, TCCSUP, and 647V-AR) and AR-negative (e.g., UMUC3-AR-short hairpin RNA [shRNA], TCCSUP-AR-shRNA, 647V) bladder cancer lines treated with dihydrotestosterone and each AR antagonist. We also used a mouse xenograft model for bladder cancer.
  
  
  
  Dihydrotestosterone increased bladder cancer cell proliferation, migration, and invasion indicating that endogenous or exogenous AR was functional. Enzalutamide, hydroxyflutamide, and bicalutamide showed similar inhibitory effects, without significant agonist activity, on androgen-mediated cell viability/apoptosis, cell migration, and cell invasion in AR-positive lines. No significant effects of dihydrotestosterone as well as AR antagonists on the growth of AR-negative cells were seen. Correspondingly, in UMUC3 cells, these AR antagonists down-regulated androgen-induced expression of AR, matrix metalloproteinase-2, and interleukin-6. Androgen-enhanced AR-mediated transcriptional activity was also blocked by each AR antagonist exhibiting insignificant agonist activity. In UMUC3 xenograft-bearing mice, oral gavage treatment with each antiandrogen retarded tumor growth, and only enzalutamide demonstrated a statistically significant suppression compared with mock treatment.
  
  
  
  Our current data support recent observations indicating the involvement of the AR pathway in bladder cancer growth and further suggest that AR antagonists, including enzalutamide, are of therapeutic benefit in AR-positive bladder cancer.
authors.affiliation: Department of Pathology and Urology, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawahara
authors.affiliation: Department of Pathology and Urology, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ide
authors.affiliation: Department of Pathology and Urology, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Eiji
authors.initials: E
authors.lastname: Kashiwagi
authors.affiliation: Department of Pathology and Urology, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Kareem A
authors.initials: KA
authors.lastname: El-Shishtawy
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Pathology and Urology, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Leonardo O
authors.initials: LO
authors.lastname: Reis
authors.affiliation: Department of Pathology and Urology, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY.
authors.forename: Yichun
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Department of Pathology and Urology, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY. Electronic address: hiroshi_miyamoto@urmc.rochester.edu.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyamoto
mesh_terms: D000726:Androgen Antagonists / Q000494:pharmacology; D000813:Anilides / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects; D001549:Benzamides; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D013196:Dihydrotestosterone / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects; D005485:Flutamide / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D009570:Nitriles / Q000494:pharmacology; D010669:Phenylthiohydantoin / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D012313:RNA / Q000378:metabolism; D011944:Receptors, Androgen / Q000378:metabolism*; D014105:Tosyl Compounds / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy* / Q000378:metabolism*
chemical_list: D000726:Androgen Antagonists; D000813:Anilides; D000970:Antineoplastic Agents; D001549:Benzamides; C508600:IL6 protein, human; D015850:Interleukin-6; D009570:Nitriles; D011944:Receptors, Androgen; D014105:Tosyl Compounds; D013196:Dihydrotestosterone; D010669:Phenylthiohydantoin; C014290:hydroxyflutamide; D012313:RNA; D005485:Flutamide; C540278:enzalutamide; C053541:bicalutamide; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2
keywords: Androgen receptor; Bicalutamide; Bladder cancer; Enzalutamide; Flutamide