CDDO induces granulocytic differentiation of myeloid leukemic blasts through translational up-regulation of p42 CCAAT enhancer binding protein alpha.

Abstract

2-Cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO) induces differentiation and apoptosis of tumor cells in vitro and in vivo. Here we assessed the effects of CDDO on CCAAT enhancer-binding protein alpha (CEBPA), a transcription factor critical for granulocytic differentiation. In HL60 acute myeloid leukemia (AML) cells, CDDO (0.01 to 2 muM) induces apoptosis in a dose-dependent manner. Conversely, subapoptotic doses of CDDO promote phagocytic activity and granulocytic-monocytic differentiation of HL60 cells through increased de novo synthesis of p42 CEBPA protein. CEBPA translational up-regulation is required for CDDO-induced granulocytic differentiation and depends on the integrity of the CEBPA upstream open reading frame (uORF). Moreover, CDDO increases the ratio of transcriptionally active p42 and the inactive p30 CEBPA isoform, which, in turn, leads to transcriptional activation of CEBPA-regulated genes (eg, GSCFR) and is associated with dephosphorylation of eIF2alpha and phosphorylation of eIF4E. In concordance with these results, CDDO induces a CEBPA ratio change and differentiation of primary blasts from patients with acute myeloid leukemia (AML). Because AML is characterized by arrested differentiation, our data suggest the inclusion of CDDO in the therapy of AML characterized by dysfunctional CEBPA expression.

• Authors: Steffen Koschmieder, Francesco D'Alò, Hanna Radomska, Christine Schöneich, Ji Suk Chang, Marina Konopleva, Susumu Kobayashi, Elena Levantini, Nanjoo Suh, Annalisa Di Ruscio, Maria Teresa Voso, Julie C Watt, Ramasamy Santhanam, Bülent Sargin, Hagop Kantarjian, Michael Andreeff, Michael B Sporn, Danilo Perrotti, Wolfgang E Berdel, Carsten Müller-Tidow, Hubert Serve, Daniel G Tenen
• Journal: Blood (Blood) Vol. 110 Issue 10 Pg. 3695-705 (Nov 15 2007) ISSN: 0006-4971 [Print] United States
• PMID: 17671235 (Publication Type: Clinical Trial, Phase I, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid
• CCAAT-Enhancer-Binding Protein-alpha
• Eukaryotic Initiation Factor-2
• Eukaryotic Initiation Factor-4E
• Oleanolic Acid

Topics

• CCAAT-Enhancer-Binding Protein-alpha (metabolism)
• Cell Differentiation (drug effects, genetics)
• Cells, Cultured
• Eukaryotic Initiation Factor-2 (metabolism)
• Eukaryotic Initiation Factor-4E (metabolism)
• Gene Expression Regulation, Leukemic (drug effects)
• Genes, abl
• Granulocytes (cytology, drug effects)
• HL-60 Cells
• Humans
• K562 Cells
• Leukemia, Myeloid (drug therapy, pathology)
• Myeloid Progenitor Cells (drug effects, metabolism)
• Oleanolic Acid (analogs & derivatives, pharmacology, therapeutic use)
• Phosphorylation (drug effects)
• Protein Biosynthesis (drug effects)
• Up-Regulation (drug effects)