1,1-Bis(3′-indolyl)-1-(p-trifluoromethylphenyl)methane (DIM-C-pPhCF3) and several p-substituted phenyl analogues have been investigated as a new class of peroxisome proliferator-activated receptor γ (PPARγ) agonists. Structure-activity studies in PPARγ-dependent transactivation assays in MCF-7 breast cancer cells show that 5-20 μM concentrations of compounds containing p-trifluoromethyl, t-butyl, cyano, dimethylamino, and phenyl groups were active, whereas p-methyl, hydrogen, methoxy, hydroxyl, or halogen groups were inactive as PPARγ agonists. Induction of PPARγ-dependent transactivation by 15-deoxy-Δ12,14-prostaglandin J2 (PGJ2) and DIM-C-pPhCF3 was inhibited in MCF-7 cells cotreated with the PPARγ-specific antagonist N-(4′-aminopyridyl -2-chloro-5-nitrobenzamide. In mammalian two-hybrid assays, DIM-C-pPhCF3 and PGJ2 (5-20 μM) induced interactions of PPARγ with steroid receptor coactivator (SRC) 1, SRC2 (TIFII), and thyroid hormone receptor-associated protein 220 but not with SRC3 (AIB1). In contrast, DIM-C-pPhCF3, but not PGJ2, induced interactions of PPARγ with PPARγ coactivator-1. C-substituted diindolylmethanes inhibit carcinogen-induced rat mammary tumor growth, induce differentiation in 3T3-L1 preadipocytes, inhibit MCF-7 cell growth and G0/G1-S phase progression, induce apoptosis, and down-regulate cyclin D1 protein and estrogen receptor α in breast cancer cells. These compounds are a novel class of synthetic PPARγ agonists that induce responses in MCF-7 cells similar to those observed for PGJ2.
|Original language||English (US)|
|Number of pages||13|
|Journal||Molecular Cancer Therapeutics|
|State||Published - Mar 2004|
ASJC Scopus subject areas
- Cancer Research