Compound A Inhibits Bladder Cancer Growth Predominantly via Glucocorticoid Receptor Transrepression

Mol Endocrinol. 2015 Oct;29(10):1486-97. doi: 10.1210/me.2015-1128. Epub 2015 Aug 31.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 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*
  • Tyramine / pharmacology
  • Urinary Bladder Neoplasms / genetics
  • Urinary Bladder Neoplasms / pathology*
  • Xenograft Model Antitumor Assays

Substances

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

Grants and funding

This work was supported part by the National Natural Science Foundation of China Grant NFSC 81202022 and the Basic Research Program of the Department of Education of Zhejiang Province Grant Y201225369 (to Y.Z.).