CDDO increases mRNA expression of CD11b, CD11c, p21cip1/waf1, and G-CSFR; induces CEBPA DNA binding; and suppresses the expression of c-myc. HL60 cells were exposed to 0.01% DMSO or 0.5 μM CDDO for the indicated times' RNA was extracted and DNAse-treated and retrotranscribed into cDNA. Subsequently, real-time PCR was performed as described in “Patients, materials, and methods.” The expression of CD11b and CD11c (A) as well as p21cip1/waf1 and c-myc (B) was assessed and is shown as the percentage of GAPDH mRNA expression. *P < .05 versus DMSO treatment (2-sided t test). (C) HL60 cells were cultured with 1 μM CDDO for the indicated time, RNA was extracted, and Northern blotting was performed using a probe for the human granulocyte colony-stimulating factor receptor (GCSFR). GAPDH mRNA expression served as a loading control. (D) Gel shift assay of CEBP protein DNA-binding activity in HL60 cells using a G-CSFR probe in the presence or absence of 1 μM CDDO (left panel). Supershift (s.s.) was analyzed using anti-CEBPA or anti-CEBPbeta antibodies (Ab). Total protein was comparable in the 3 lysates (right panel).
