Immortalization of a multipotent murine hematopotic progenitor by retrovirallytransduced hrx-enl

Journal Article

Chromosomal abnormalities involving the HRX gene (band 1 Iq23) are frequently found in a wide variety of myeloid or lymphoid leukemias. Often the leukemic cells exhibit features of mixed lineage differentiation, suggesting the transformation of a multipotent precursor. One common HRX fusion partner is the ENL gene on chromosome 19. To address whether HRX-ENL can transform hematopoietic stem cells (HSC), Thy-l'Sca-rH-2Khi cells (enriched in HSC) were isolated by fluorescence activated cell sorting from the bone marrow of mice treated 2 days previously with 5-fluorouracil and infected with a retroviral vector carrying the HRX-ENL fusion cDNA. The transduced cells were then cloned by limiting dilution or methylcellulose colony isolation and more than 20 cell lines were established in liquid culture containing Steel factor (SLF). Southern blot analysis verified that these immortalized cells contained 1 to 3 copies of the structurally intact HRX-ENL provirus and were monoclonal. All the cell lines expressed the Mac-1 and Gr1 myeloid markers to various degrees and spontaneously generated some macrophages and/or granulocytes on prolonged culture in SLF. Eight of the cell lines also expressed lymphoid markers (B220 and/or Thy-1). Five of these 8 cell lines which expressed lymphoid and myeloid markers also expressed the stem cell antigen Sca-1. When these cells were cultured on an adherent layer of Sys-1 stromal cells in the presence of IL-7, up to 80 % of the cells expressed CD19+ after 3 weeks. We are currently studying the multilineage differentiation potential of these HRX-ENL cells following transplantation into syngeneic mice. Our current results provide direct evidence that expression of HRX-ENL can immortalize a hernatopoietic progenitor with both myeloid and lymphoid differentiation potential and recapitulates the diversity of the HRX-ENL-associated leukemias in man.

Duke Authors

Cited Authors

  • Lavau, C; Szilvassy, SJ; Du, C; Slany, R; Cleary, ML

Published Date

  • December 1, 1997

Published In

Volume / Issue

  • 25 / 8

Start / End Page

  • 834 -

International Standard Serial Number (ISSN)

  • 0301-472X

Citation Source

  • Scopus