New in vitro tools to study human constitutive androstane receptor (CAR) biology: discovery and comparison of human CAR inverse agonists

Mol Pharm. 2011 Dec 5;8(6):2424-33. doi: 10.1021/mp2003658. Epub 2011 Nov 1.


The human constitutive androstane receptor (CAR, NR1I3) is one of the key regulators of xenobiotic and endobiotic metabolism. The unique properties of human CAR, such as the high constitutive activity and the complexity of signaling, as well as the lack of functional and predictive cell-based assays to study the properties of the receptor, have hindered the discovery of selective human CAR ligands. Here we report a novel human CAR inverse agonist, 1-[(2-methylbenzofuran-3-yl)methyl]-3-(thiophen-2-ylmethyl) urea (S07662), which suppresses human CAR activity, recruits the corepressor NCoR in cell-based assays, and attenuates the phenytoin- and 6-(4-chlorophenyl)imidazo[2,1-b][1,3]thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO)-induced expression of CYP2B6 mRNA in human primary hepatocytes. The properties of S07662 are also compared with those of known human CAR inverse agonists by using an array of different in vitro and in silico assays. The identified compound S07662 can be used as a chemical tool to study the biological functions of human CAR and also as a starting point for the development of new drugs for various conditions involving the receptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / chemistry
  • Cell Line, Tumor
  • Constitutive Androstane Receptor
  • Drug Discovery*
  • Humans
  • Isoquinolines / chemistry
  • Methylurea Compounds / chemistry*
  • Models, Molecular
  • Molecular Dynamics Simulation
  • Receptors, Cytoplasmic and Nuclear / agonists*
  • Thiophenes / chemistry*


  • 1-((2-methylbenzofuran-3-yl)methyl)-3-(thiophen-2-ylmethyl)urea
  • Antineoplastic Agents
  • Constitutive Androstane Receptor
  • Isoquinolines
  • Methylurea Compounds
  • NR1I3 protein, human
  • Receptors, Cytoplasmic and Nuclear
  • Thiophenes
  • PK 11195