Reintroduction of CEBPA in MN1-overexpressing hematopoietic cells prevents their hyperproliferation and restores myeloid differentiation

• Published in: Blood Vol. 114; no. 8; pp. 1596 - 1606
• Main Authors: Kandilci, Ayten, Grosveld, Gerard C.
• Format: Journal Article
• Language: English
• Published: Washington, DC Elsevier Inc 20.08.2009; Americain Society of Hematology; American Society of Hematology
• Series: Myeloid Neoplasia
• Subjects: Animals; Biological and medical sciences; CCAAT-Enhancer-Binding Proteins - genetics; CCAAT-Enhancer-Binding Proteins - physiology; Cell Differentiation - drug effects; Cell Differentiation - genetics; Cell differentiation, maturation, development, hematopoiesis; Cell physiology; Cell Proliferation; Cells, Cultured; Cholecalciferol - pharmacology; Fundamental and applied biological sciences. Psychology; Hematopoietic Stem Cells - drug effects; Hematopoietic Stem Cells - metabolism; Hematopoietic Stem Cells - physiology; HL-60 Cells; Humans; Mice; Molecular and cellular biology; Myeloid Cells - drug effects; Myeloid Cells - metabolism; Myeloid Cells - physiology; Myeloid Neoplasia; Trans-Activators; Transfection; Tretinoin - pharmacology; Tumor Suppressor Proteins - genetics; Tumor Suppressor Proteins - metabolism; U937 Cells; Human; Cell proliferation; Prevention; Vertebrata; Mammalia; Transcription factor C/EBPα; Mouse; Animal; Rodentia; Hematopoietic cell; Gene overexpression; Cell differentiation
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2009-02-205443

Forced expression of MN1 in primitive mouse hematopoietic cells causes acute myeloid leukemia and impairs all-trans retinoic acid-induced granulocytic differentiation. Here, we studied the effects of MN1 on myeloid differentiation and proliferation using primary human CD34+ hematopoietic cells, lineage-depleted mouse bone marrow cells, and bipotential (granulocytic/monocytic) human acute myeloid leukemia cell lines. We show that exogenous MN1 stimulated the growth of CD34+ cells, which was accompanied by enhanced survival and increased cell cycle traverse in cultures supporting progenitor cell growth. Forced MN1 expression impaired both granulocytic and monocytic differentiation in vitro in primary hematopoietic cells and acute myeloid leukemia cell lines. Endogenous MN1 expression was higher in human CD34+ cells compared with both primary and in vitro–differentiated monocytes and granulocytes. Microarray and real-time reverse-transcribed polymerase chain reaction analysis of MN1-overexpressing CD34+ cells showed down-regulation of CEBPA and its downstream target genes. Reintroduction of conditional and constitutive CEBPA overcame the effects of MN1 on myeloid differentiation and inhibited MN1-induced proliferation in vitro. These results indicate that down-regulation of CEBPA activity contributes to MN1-modulated proliferation and impaired myeloid differentiation of hematopoietic cells.