Enforced expression of NUP98-HOXA9 in human CD34(+) cells enhances stem cell proliferation. Academic Article uri icon

Overview

abstract

  • The t(7;11)(p15;p15) translocation, observed in acute myelogenous leukemia and myelodysplastic syndrome, generates a chimeric gene where the 5' portion of the sequence encoding the human nucleoporin NUP98 protein is fused to the 3' region of HOXA9. Here, we show that retroviral-mediated enforced expression of the NUP98-HOXA9 fusion protein in cord blood-derived CD34(+) cells confers a proliferative advantage in both cytokine-stimulated suspension cultures and stromal coculture. This advantage is reflected in the selective expansion of hematopoietic stem cells as measured in vitro by cobblestone area-forming cell assays and in vivo by competitive repopulation of nonobese diabetic/severe combined immunodeficient mice. NUP98-HOXA9 expression inhibited erythroid progenitor differentiation and delayed neutrophil maturation in transduced progenitors but strongly enhanced their serial replating efficiency. Analysis of the transcriptosome of transduced cells revealed up-regulation of several homeobox genes of the A and B cluster as well as of Meis1 and Pim-1 and down-modulation of globin genes and of CAAT/enhancer binding protein alpha. The latter gene, when coexpressed with NUP98-HOXA9, reversed the enhanced proliferation of transduced CD34(+) cells. Unlike HOXA9, the NUP98-HOXA9 fusion was protected from ubiquitination mediated by Cullin-4A and subsequent proteasome-dependent degradation. The resulting protein stabilization may contribute to the leukemogenic activity of the fusion protein.

publication date

  • December 15, 2006

Research

keywords

  • Antigens, CD34
  • Homeodomain Proteins
  • Mutant Chimeric Proteins
  • Nuclear Pore Complex Proteins
  • Stem Cells

Identity

Scopus Document Identifier

  • 33846199172

Digital Object Identifier (DOI)

  • 10.1158/0008-5472.CAN-06-0706

PubMed ID

  • 17178874

Additional Document Info

volume

  • 66

issue

  • 24