Ddx18 is essential for cell-cycle progression in zebrafish hematopoietic cells and is mutated in human AML Academic Article uri icon

Overview

MeSH Major

  • Cell Cycle
  • DEAD-box RNA Helicases
  • Hematopoiesis
  • Hematopoietic Stem Cells
  • Leukemia, Myeloid, Acute
  • Zebrafish
  • Zebrafish Proteins

abstract

  • 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 ddx18(hi1727/+) 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.

publication date

  • July 28, 2011

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC3148170

Digital Object Identifier (DOI)

  • 10.1182/blood-2010-11-318022

PubMed ID

  • 21653321

Additional Document Info

start page

  • 903

end page

  • 15

volume

  • 118

number

  • 4