Retroviral Insertional Mutagenesis Identifies Genes that Collaborate with NUP98-HOXD13 during Leukemic Transformation

Abstract

The t(2;11)(q31;p15) chromosomal translocation results in a fusion between the NUP98 and HOXD13 genes and has been observed in patients with myelodysplastic syndrome (MDS) or acute myelogenous leukemia. We previously showed that expression of the NUP98-HOXD13 (NHD13) fusion gene in transgenic mice results in an invariably fatal MDS; approximately one third of mice die due to complications of severe pancytopenia, and about two thirds progress to a fatal acute leukemia. In the present study, we used retroviral insertional mutagenesis to identify genes that might collaborate with NHD13 as the MDS transformed to an acute leukemia. Newborn NHD13 transgenic mice and littermate controls were infected with the MOL4070LTR retrovirus. The onset of leukemia was accelerated, suggesting a synergistic effect between the NHD13 transgene and the genes neighboring retroviral insertion events. We identified numerous common insertion sites located near protein-coding genes and confirmed dysregulation of a subset of these by expression analyses. Among these genes were Meis1, a known collaborator of HOX and NUP98-HOX fusion genes, and Mn1, a transcriptional coactivator involved in human leukemia through fusion with the TEL gene. Other putative collaborators included Gata2, Erg, and Epor. Of note, we identified a common insertion site that was >100 kb from the nearest coding gene, but within 20 kb of the miR29a/miR29b1 microRNA locus. Both of these miRNA were up-regulated, demonstrating that retroviral insertional mutagenesis can target miRNA loci as well as protein-coding loci. Our data provide new insights into NHD13-mediated leukemogenesis as well as retroviral insertional mutagenesis mechanisms.

Genetic and epigenetic factors in regulation of microRNA in colorectal cancers

“…A single nucleotide replacement resulting from a mutation or an SNP can be involved in deregulation of miRNA expression [32,[35][36][37]. Some studies indicated the association of SNPs in miR-146a, miR-196a2, miR-149 and miR-499 with variable risk in cancers [38,21,[39][40][41].…”

Standardization of flow cytometry in myelodysplastic syndromes: report from the first European LeukemiaNet working conference on flow cytometry in myelodysplastic syndromes

“…First data are currently being reported on microRNA expression profiling in MDS. [23][24][25][26][27][28][29] Although the WPSS provides a superior prognostic algorithm compared to IPSS, FCM may further improve diagnosis and prognostication. Prospective studies are now beginning to further assess the relevance of WPSS and FCM in MDS.…”

“…It should be noted, however, that density separation may be preferable for specific applications such as assessment of the erythroid lineage. 24 …”

Acceleration of chronic myeloproliferation by enforced expression of Meis1 or Meis3 in Icsbp-deficient bone marrow cells

“…In one tumor, viral integration occurred in the first intron of Mn1 gene (Figure 2b). Similar retroviral integrations have recently been shown to collaborate with NUP98-HoxD13 in leukemic transformation (Slape et al, 2007). No integration sites were found in the HoxA9 locus.…”