CDDO down-regulation of the antiapoptotic protein FLIP in CLL.

CLL B cells were cultured for 24 hours in the presence or absence of 1 μM CDDO, 0.5 μM CDDO-Me, or 10 μM troglitazone. CLL B cells were recovered from cultures, and the percentage of apoptosis was determined by annexin V–FITC/PI double staining with the use of flow cytometry analysis. Alternatively, protein-containing lysates were prepared, normalized for total protein content (12.5 μg per lane), and analyzed by SDS-PAGE/immunoblot assay with the use of antibodies specific for DR4, DR5, FADD, DAP3, FLIP, or β-actin. (A) Two representative patient samples are shown of a total of 12 analyzed. (B) A dose response is shown for CDDO at 0.1 to 1.0 μM (means ± SD; n = 3).