Novel VDR antagonists based on the GW0742 scaffold

Area of Science:

• Medicinal Chemistry
• Molecular Pharmacology
• Endocrinology

Background:

• The vitamin D receptor (VDR) is a nuclear hormone receptor crucial for regulating cell proliferation, differentiation, and calcium homeostasis.
• VDR activity is primarily modulated by its endogenous ligand, 1,25-dihydroxyvitamin D3.
• Existing VDR antagonists are mainly based on the secosteroid scaffold of vitamin D, with few non-secosteroid alternatives available.

Purpose of the Study:

• To rationally design novel non-secosteroid VDR antagonists.
• To utilize GW0742, a known PPARδ agonist and VDR antagonist, as a scaffold for new VDR antagonist development.
• To identify compounds with potent VDR antagonism while lacking PPARδ agonism.

Main Methods:

• Rational drug design based on the GW0742 scaffold.
• Chemical synthesis involving modification of the GW0742 structure, including replacing the thiazole ring with an oxazole ring.
• Functional assays to assess inhibition of VDR-mediated transcription (e.g., IC50 determination).
• Assays to evaluate potential off-target effects on other nuclear receptors, including PPARδ.

Main Results:

• A novel non-secosteroid VDR antagonist, compound 7b, was successfully designed and synthesized.
• Compound 7b demonstrated potent inhibition of VDR-mediated transcription with an IC50 of 660 nM.
• Compound 7b selectively inhibited VDR activity without activating PPARδ-mediated transcription.
• Off-target transcriptional inhibition by compound 7b on other nuclear receptors was observed.

Conclusions:

• The study successfully developed a novel class of non-secosteroid VDR antagonists derived from the GW0742 scaffold.
• Compound 7b represents a promising lead compound for VDR antagonism, exhibiting selectivity over PPARδ.
• Further investigation is warranted to fully characterize the off-target effects and therapeutic potential of these new VDR antagonists.