1. Academic Validation
  2. Identification and mechanism of action of the acylguanidine MRT-83, a novel potent Smoothened antagonist

Identification and mechanism of action of the acylguanidine MRT-83, a novel potent Smoothened antagonist

  • Mol Pharmacol. 2011 Mar;79(3):453-60. doi: 10.1124/mol.110.069708.
Hermine Roudaut 1 Elisabeth Traiffort Tatiana Gorojankina Ludwig Vincent Helene Faure Angele Schoenfelder Andre Mann Fabrizio Manetti Antonio Solinas Maurizio Taddei Martial Ruat
Affiliations

Affiliation

  • 1 Laboratoire de Neurobiologie et Développement, Institut de Neurobiologie Alfred Fessard IFR2118, Centre National de la Recherche Scientifique, UPR-3294, Gif-sur-Yvette, France.
Abstract

There is a clear need to develop novel pharmacological tools to improve our understanding of Smoothened (Smo) function in normal and pathological states. Here, we report the discovery, the mechanism of action, and the in vivo activity of N-(2-methyl-5-(3-(3,4,5-trimethoxybenzoyl)guanidino)phenyl)biphenyl-4-carboxamide (MRT-83), a novel potent antagonist of Smo that belongs to the acylguanidine family of molecules. MRT-83 fits to a proposed pharmacophoric model for Smo antagonists with three hydrogen bond acceptor groups and three hydrophobic regions. MRT-83 blocks Hedgehog (Hh) signaling in various assays with an IC50 in the nanomolar range, showing greater potency than the reference Smo antagonist cyclopamine. MRT-83 inhibits Bodipy-cyclopamine binding to human and mouse Smo but does not modify Wnt signaling in human embryonic kidney 293 transiently transfected with a Tcf/Lef-dependent Firefly luciferase reporter together with a Renilla reniformis luciferase control reporter. MRT-83 abrogates the agonist-induced trafficking of endogenous mouse or human Smo to the primary cilium of C3H10T1/2 or NT2 cells that derive from a pluripotent testicular carcinoma. Stereotaxic injection into the lateral ventricle of adult mice of MRT-83 but not of a structurally related compound inactive at Smo abolished up-regulation of Patched transcription induced by Sonic Hedgehog in the neighboring subventricular zone. These data demonstrate that MRT-83 efficiently antagonizes Hh signaling in vivo. All together, these molecular, functional and biochemical studies provide evidence that MRT-83 interacts with Smo. Thus, this novel Smo antagonist will be useful for manipulating Hh signaling and may help develop new therapies against Hh-pathway related diseases.

Figures
Products
  • Cat. No.
    Product Name
    Description
    Target
    Research Area
  • HY-18287
    99.27%, Smoothened Antagonist
    Smo