Modeling, Synthesis, and Biological Evaluation of Potential Retinoid X Receptor (RXR)-Selective Agonists: Analogues of 4-[1-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)ethynyl]benzoic Acid (Bexarotene) and 6-(Ethyl(5,5,8,8-tetrahydronaphthalen-2-yl)amino)nicotinic Acid (NEt-TMN)

J Med Chem. 2016 Oct 13;59(19):8924-8940. doi: 10.1021/acs.jmedchem.6b00812. Epub 2016 Sep 19.

Abstract

Sulfonic acid analogues of 4-[1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)ethynyl]benzoic acid (bexarotene, 1) as well as seven novel and two reported analogues of 6-(ethyl(5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalen-2-yl)amino)nicotinic acid (NEt-TMN) were synthesized and assessed for selective retinoid X receptor (RXR) agonism. Compound 1 is FDA-approved for treatment of cutaneous T-cell lymphoma (CTCL); however, 1 can provoke side effects by impacting RXR-dependent receptor pathways. All of the analogues in this study were evaluated for their potential to bind RXR through modeling and then assayed in an RXR-RXR mammalian-2-hybrid (M2H) system and in RXR-responsive element (RXRE)-mediated transcriptional experiments. The EC50 profiles for these unique analogues and their analogous effectiveness to inhibit proliferation in CTCL cells relative to 1 suggest that these compounds possess similar or even enhanced therapeutic potential. Several compounds also displayed more selective RXR activation with minimal cross-signaling of the retinoic acid receptor. These results suggest that modifications of potent RXR agonists such as NEt-TMN can lead to improved biological selectivity and potency compared with the known therapeutic.

MeSH terms

  • Antineoplastic Agents / chemistry*
  • Antineoplastic Agents / pharmacology*
  • Bexarotene
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Gene Expression Regulation, Neoplastic / drug effects
  • HEK293 Cells
  • Histone Deacetylase 1 / genetics
  • Humans
  • Lymphoma, T-Cell, Cutaneous / drug therapy
  • Lymphoma, T-Cell, Cutaneous / genetics
  • Lymphoma, T-Cell, Cutaneous / metabolism
  • Models, Molecular
  • Niacin / analogs & derivatives
  • Niacin / pharmacology
  • Retinoid X Receptors / agonists*
  • Retinoid X Receptors / metabolism
  • Sterol Regulatory Element Binding Proteins / genetics
  • Tetrahydronaphthalenes / chemistry*
  • Tetrahydronaphthalenes / pharmacology*

Substances

  • Antineoplastic Agents
  • Retinoid X Receptors
  • Sterol Regulatory Element Binding Proteins
  • Tetrahydronaphthalenes
  • Niacin
  • Bexarotene
  • Histone Deacetylase 1