Abstract
Di(1H-indol-3-yl)(4-trifluoromethylphenyl)methane (DIM-Ph-4-CF3) is an analog of orphan nuclear receptor 4A1 (NR4A1) ligand cytosporone B. We have synthesized several oxidation products of DIM-Ph-4-CF3, focusing on analogs with electronwithdrawing or donating groups at their phenyl ring 4-positions, and examined their anti-cancer activity and mechanism-of-action. Mesylates (DIM-Ph-4-X+ OMs-s) having CF3, CO2Me and Cl groups were more effective inhibitors of cancer cell viability than their precursors. 19F NMR spectroscopy and differential scanning calorimetry strongly indicated interactions of DIM-Ph-4-CF+3 OMs- with the NR4A1 ligand binding domain, and compound-induced apoptosis of prostate cancer cells was dependent on NR4A1. DIM-Ph-4-CF+3 OMs- showed robust inhibition of LNCaP prostate cancer xenografts with no apparent toxicity. In vitro and in vivo, DIM-Ph-4-CF+3 OMs- activated proapoptotic unfolded protein response (UPR) signaling in prostate cancer cells. Independently of DIM-Ph-4-CF+3 OMs-, the bulk of NR4A1 localized to the cytoplasm in various cancer cell lines, suggesting a cytoplasmic mechanism-of-action of DIMPh- 4-CF+3 OMs- in UPR induction and cell death. In summary, the data suggest that oxidized analogs of DIM-Ph-4-CF3 possess potent and safe anti-cancer activity which is mediated through UPR signaling downstream of NR4A1 binding.
Original language | English (US) |
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Pages (from-to) | 25057-25074 |
Number of pages | 18 |
Journal | Oncotarget |
Volume | 9 |
Issue number | 38 |
DOIs | |
State | Published - May 18 2018 |
Keywords
- Apoptosis
- Orphan nuclear receptor 4A1
- Oxidation products
- Prostate cancer
- Unfolded protein response
ASJC Scopus subject areas
- Oncology