title: Detection, isolation, and stimulation of quiescent primitive leukemic progenitor cells from patients with acute myeloid leukemia (AML).
abstract: Although many acute myeloid leukemia (AML) colony-forming cells (CFCs) and long-term culture-initiating cells (LTC-ICs) directly isolated from patients are actively cycling, quiescent progenitors are present in most samples. In the current study, (3)H-thymidine ((3)H-Tdr) suicide assays demonstrated that most NOD/SCID mouse leukemia-initiating cells (NOD/SL-ICs) are quiescent in 6 of 7 AML samples. AML cells in G(0), G(1), and S/G(2)+M were isolated from 4 of these samples using Hoechst 33342/pyroninY staining and cell sorting. The progenitor content of each subpopulation was consistent with the (3)H-Tdr suicide results, with NOD/SL-ICs found almost exclusively among G(0) cells while the cycling status of AML CFCs and LTC-ICs was more heterogeneous. Interestingly, after 72 hours in serum-free culture with or without Steel factor (SF), Flt-3 ligand (FL), and interleukin-3 (IL-3), most G(0) AML cells entered active cell cycle (percentage of AML cells remaining in G(0) at 72 hours, 1.2% to 37%, and 0% to 7.6% in cultures without and with growth factors [GFs], respectively) while G(0) cells from normal lineage-depleted bone marrow remained quiescent in the absence of GF. All 4 AML samples showed evidence of autocrine production of 2 or more of SF, FL, IL-3, and granulocyte-macrophage colony-stimulating factor (GM-CSF). In addition, 3 of 4 samples contained an internal tandem duplication of the FLT3 gene. In summary, quiescent leukemic cells, including NOD/SL-ICs, are present in most AML patients. Their spontaneous entry into active cell cycle in short-term culture might be explained by the deregulated GF signaling present in many AMLs.
authors.affiliation: Terry Fox Laboratory, British Columbia Cancer Agency, and the Department of Medicine, University of British Columbia, Vancouver, Canada.
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Guan
authors.forename: Brigitte
authors.initials: B
authors.lastname: Gerhard
authors.forename: Donna E
authors.initials: DE
authors.lastname: Hogge
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D019898:Autocrine Communication; D002455:Cell Division; D002469:Cell Separation; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D004261:DNA Replication; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007377:Interleukin-3 / Q000494:pharmacology; D015470:Leukemia, Myeloid, Acute / Q000473:pathology*; D015479:Leukemia, Myelomonocytic, Acute / Q000473:pathology*; D008297:Male; D008565:Membrane Proteins / Q000494:pharmacology; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D008875:Middle Aged; D009368:Neoplasm Transplantation; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000473:pathology* / Q000637:transplantation; D011828:Radiation Chimera; D016192:Resting Phase, Cell Cycle / Q000187:drug effects; D013194:Staining and Labeling; D019089:Stem Cell Factor / Q000494:pharmacology
chemical_list: D016895:Culture Media, Serum-Free; D007377:Interleukin-3; D008565:Membrane Proteins; D019089:Stem Cell Factor; C084881:flt3 ligand protein