Compound A Inhibits Bladder Cancer Growth Predominantly via Glucocorticoid Receptor Transrepression.

Abstract

Recent evidence indicates that glucocorticoids (GCs) suppress bladder cancer cell invasion through the GC receptor (GR) pathway, whereas androgen-mediated androgen receptor (AR) signals induce bladder tumor progression. In this study, we assessed the effects of 2-(4-acetoxyphenyl)-2-chloro-N-methyl-ethylammonium chloride (compound A [CpdA]), which was shown to function as not only a GR modulator but also an AR antagonist, on the growth of bladder cancer. In GR/AR-positive cells, CpdA strongly inhibited cell proliferation and colony formation as well as increased G1 phase-arrested cell population and apoptosis. Specifically, CpdA at 1μM decreased cell viability of TCCSUP/UMUC3-control-short hairpin RNA (shRNA), TCCSUP/UMUC3-GR-shRNA, and TCCSUP/UMUC3-AR-shRNA by 50%/67%, 25%/26%, and 38%/58%, respectively. CpdA also inhibited cell migration and invasion of GR/AR-positive (up to 61% decrease) and GR-positive/AR-silencing (up to 51% decrease) lines and, less strongly, those of GR-silencing/AR-positive lines (up to 35% decrease). Additionally, in UMUC3-control xenograft-bearing male mice, CpdA more strongly suppressed tumor growth than dexamethasone or hydroxyflutamide. In reporter gene assays, CpdA failed to induce GR transactivation, whereas it antagonized dihydrotestosterone-enhanced AR transactivation. In contrast, CpdA reduced nuclear factor (NF)-κB and activator protein 1 transcriptional activities, indicating induction of GR-mediated transrepression. Correspondingly, the expression of NF-κB-related molecules, matrix metalloproteinase-2, matrix metalloproteinase-9, interleukin-6, and vascular endothelial growth factor, was significantly down-regulated by CpdA in control lines but not in GR-silencing cells. Moreover, coimmunoprecipitation showed that CpdA promoted the interactions between GR and NF-κB. Thus, CpdA likely inhibits bladder cancer growth predominantly via inducing GR transrepression and at least partially mediated through the AR pathway, suggesting its effects more beneficial than GCs/pure GR ligands or AR antagonists.

• Authors: Yichun Zheng, Hitoshi Ishiguro, Hiroki Ide, Satoshi Inoue, Eiji Kashiwagi, Takashi Kawahara, Mehrsa Jalalizadeh, Leonardo O Reis, Hiroshi Miyamoto
• Journal: Molecular endocrinology (Baltimore, Md.) (Mol Endocrinol) Vol. 29 Issue 10 Pg. 1486-97 (Oct 2015) ISSN: 1944-9917 [Electronic] United States
• PMID: 26322830 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 2-(4-acetoxyphenyl)-2-chloro-N-methylethylamine
• Acetates
• Androgen Antagonists
• NF-kappa B
• Receptors, Glucocorticoid
• Repressor Proteins
• Tyramine

Topics

• Acetates (pharmacology)
• Androgen Antagonists (pharmacology)
• Animals
• Apoptosis (drug effects)
• Cell Cycle (drug effects)
• Cell Line, Tumor
• Cell Proliferation (drug effects)
• Humans
• Mice, Inbred NOD
• Mice, SCID
• NF-kappa B (metabolism)
• Neoplasm Invasiveness
• Protein Binding (drug effects)
• Receptors, Glucocorticoid (genetics)
• Repressor Proteins (metabolism)
• Transcriptional Activation (genetics)
• Tyramine (analogs & derivatives, pharmacology)
• Urinary Bladder Neoplasms (genetics, pathology)
• Xenograft Model Antitumor Assays