CDDO-Im (TP-235) is an activator of Nrf2 and PPAR (Kis: 232/344 nM for PPARα/PPARγ).

CDDO-Im is highly active in suppressing cellular proliferation of human leukemia and breast cancer cell lines (IC50 approximately 10-30 nM). In U937 leukemia cells, CDDO-Im also induces monocytic differentiation as measured by increased cell surface expression of CD11b and CD36 [1]. CDDO-Im treatment markedly induces cell cycle arrest at G2/M-phase and apoptosis in the triple-negative breast cancer cell lines, SUM159 and MDA-MB-231. The CD24?/EpCAM+ cells in SUM159 tumorspheres are significantly inhibited by CDDO-Im treatment. CDDO-Im also significantly decreases sphere-forming efficiency and tumorsphere size in both primary and secondary sphere cultures [2]. Treatment with CDDO-Im elevates protein levels of Nrf2, a transcription factor previously shown to bind ARE sequences and increases expression of a number of antioxidant and detoxification genes regulated by Nrf2 [3].

CDDO-Im exhibits strong inhibition of de novo inducible nitric oxide synthase (iNOS) expression in primary mouse macrophages. Additionally, it effectively suppresses the proliferation of B16 murine melanoma and L1210 murine leukemia cells in vivo. Administering 10 nM (5.4 μg) of CDDO-Im significantly impedes the induction of iNOS by IFN-γ, while a dose as low as 1 nmol (0.54 μg) of CDDO-Im shows partial effectiveness [1].

CDDO-Im is dissolved in DMSO. SUM159 and MDA-MB-231 cells are seeded into each well of 96-well plates (1,000 cell/well) and treated the next day with vehicle control or CDDO-Im (1, 10, 50, 100 and 200 nM) for given incubation time. The absorbance is measured with a spectrophotometer to determine the cell proliferation rate [2].

Mice are injected i.p. with thioglycollate, and the resulting resident peritoneal macrophages are activated 3 days later with an i.p. injection of IFN-γ. CDDO and CDDO-Im are injected i.p. 30 min after IFN-γ. Macrophages are harvested 10 h later, cultured for 12 h, and then assayed for expression of iNOS protein and production of nitric oxide (NO) [1].