Ddx18 is essential for cell cycle progression in zebrafish hematopoietic cells and is mutated in human acute myeloid leukemia
- Authors
- Payne, E.M., Bolli, N., Rhodes, J., Abdel-Wahab, O.I., Levine, R., Hedvat, C.V., Stone, R., Khanna-Gupta, A., Sun, H., Kanki, J.P., Gazda, H.T., Beggs, A.H., Cotter, F.E., and Look, A.T.
- ID
- ZDB-PUB-110613-24
- Date
- 2011
- Source
- Blood 118(4): 903-15 (Journal)
- Registered Authors
- Beggs, Alan H., Bolli, Niccolo, Kanki, John, Look, A. Thomas, Payne, Elspeth M. (Beth), Rhodes, Jennifer
- Keywords
- none
- MeSH Terms
-
- Alleles
- Animals
- Blotting, Western
- Cell Cycle/genetics*
- Cell Separation
- DEAD-box RNA Helicases/genetics*
- DEAD-box RNA Helicases/metabolism*
- Embryo, Nonmammalian
- Flow Cytometry
- Hematopoiesis/genetics*
- Hematopoietic Stem Cells/cytology
- Hematopoietic Stem Cells/metabolism*
- Humans
- In Situ Hybridization
- Leukemia, Myeloid, Acute/genetics*
- Mutagenesis, Site-Directed
- Mutation
- Myeloid Cells/cytology
- Myeloid Cells/metabolism
- Polymerase Chain Reaction
- Zebrafish/metabolism*
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism*
- PubMed
- 21653321 Full text @ Blood
In a zebrafish mutagenesis screen to identify genes essential for myelopoiesis, we identified an insertional allele hi1727, which disrupts the gene encoding RNA helicase dead-box 18 (Ddx18). Homozygous Ddx18 mutant embryos exhibit a profound loss of myeloid and erythroid cells along with cardiovascular abnormalities and reduced size. These mutants also display prominent apoptosis and a G1 cell-cycle arrest. Loss of p53, but not Bcl-xl overexpression, rescues myeloid cells to normal levels, suggesting that the hematopoietic defect is because of p53-dependent G1 cell-cycle arrest. We then sequenced primary samples from 262 patients with myeloid malignancies because genes essential for myelopoiesis are often mutated in human leukemias. We identified 4 nonsynonymous sequence variants (NSVs) of DDX18 in acute myeloid leukemia (AML) patient samples. RNA encoding wild-type DDX18 and 3 NSVs rescued the hematopoietic defect, indicating normal DDX18 activity. RNA encoding one mutation, DDX18-E76del, was unable to rescue hematopoiesis, and resulted in reduced myeloid cell numbers in ddx18hi1727/+ embryos, indicating this NSV likely functions as a dominant-negative allele. These studies demonstrate the use of the zebrafish as a robust in vivo system for assessing the function of genes mutated in AML, which will become increasingly important as more sequence variants are identified by next-generation resequencing technologies.