2,4-Heptadienamide, 6-[(1R,3aS,4E,7aR)-4-[2-[(3R,5R)-3,5-dihydroxycyclohexylidene]ethylidene]octahydro-7a-methyl-1H-inden-1-yl]-N-hydroxy-4-methyl-, (2E,4E,6R)-

Triciferol functions as a multiple ligand with combined VDR agonist and HDAC antagonist activities. Triciferol binds directly to the VDR (IC50=87 nM), and functions as an agonist with 1,25D-like potency on several 1,25D target genes. Triciferol induces marked tubulin hyperacetylation, and augments histone acetylation. Antiproliferative and cytotoxic activities[1].

Triciferol (0-10000 nM; 0-72 hours) is significantly more efficacious in suppressing the proliferation of estrogen receptor-negative human MDA-MB231 breast cancer cells[1].Treatment of MCF-7 cells with Triciferol (100-1000 nM) induces ≈2.5-fold higher rates of cell death than equimolar amounts of 1,25D[1].

[1]. Tavera-Mendoza LE, et al. Incorporation of histone deacetylase inhibition into the structure of a nuclear receptor agonist. Proc Natl Acad Sci U S A. 2008;105(24):8250-8255.