[Frontiers in Bioscience 17, 1120-1139, January 1, 2012]

RUNX1 and RUNX1-ETO: roles in hematopoiesis and leukemogenesis

Kentson Lam1, Dong-Er Zhang1

1Moores Cancer Center, Department of Pathology and Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA


1. Abstract
2. Introduction
3. RUNX1 structure and regulation
3.1. RUNX1 promoters (proximal and distal) and RUNX1 isoforms
3.2. RUNX1 structure, protein domains and functions
3.3. Post-translational modifications of RUNX1
4. RUNX1 as a master regulator of hematopoiesis
4.1. The role of RUNX1 in the specification and development of the definitive hematopoietic stem cell
4.2. RUNX1 target genes as they relate to hematopoiesis
4.3. Mutations in RUNX1 lead to aberrant hematopoiesis
5. RUNX1 is a commonly found constituent in chromosomal translocations associated with cancer
6. RUNX1-ETO structure and regulation
6.1. RUNX1-ETO protein domains and interactions
6.2. RUNX1-ETO splice isoforms and effects on leukemogenesis
6.3. Post-translational modifications of RUNX1-ETO
7. RUNX1-ETO and induction of leukemia
7.1. Effects on hematopoiesis through the use of animal models
7.2. RUNX1-ETO target genes
7.3. Regulation of chromatin structure
8. Perspectives
9. Acknowledgments
10. References


RUNX1 is a transcription factor that regulates critical processes in many aspects of hematopoiesis. RUNX1 is also integral in defining the definitive hematopoietic stem cell. In addition, many hematological diseases like myelodysplastic syndrome and myeloproliferative neoplasms have been associated with mutations in RUNX1. Located on chromosomal 21, the RUNX1 gene is involved in many forms of chromosomal translocations in leukemia. t(8;21) is one of the most common chromosomal translocations found in acute myeloid leukemia (AML), where it results in a fusion protein between RUNX1 and ETO. The RUNX1-ETO fusion protein is found in approximately 12% of all AML patients. In this review, we detail the structural features, functions, and models used to study both RUNX1 and RUNX1-ETO in hematopoiesis over the past two decades.