title: Steel factor (c-kit ligand) promotes the survival of hematopoietic stem/progenitor cells in the absence of cell division.
abstract: It is known that the majority of primitive hematopoietic progenitors are in a noncycling quiescent state. In addition, normal hematopoietic progenitors and progenitor cell lines show an absolute dependence on growth factors for their survival in vitro, yet the effect of growth factors on progenitor cell survival has not been separated from effects on both proliferation and differentiation. Using an in vitro assay system, we examined whether growth factors could promote the survival of stem cells in culture in the absence of cell division. These studies show that steel factor (SLF) and, to a lesser extent, interleukin-3 (IL-3) directly promoted the survival of elutriated bone marrow progenitor cells (countercurrent centrifugal elutriation [CCE]-27) that are enriched for primitive hematopoietic progenitors that respond to the combination of SLF plus IL-3. Furthermore, SLF promoted the survival of short-term reconstituting cells (STRC), and long-term reconstituting cells (LTRC) with trilineage reconstitution potential in vivo. In comparison, granulocyte colony-stimulating factor (G-CSF), IL-6, leukemia inhibitory factor, IL-11, IL-1, granulocyte macrophage CSF (GM-CSF), and macrophage CSF (M-CSF) had no effect on the survival of these cells. In the presence of mitotic inhibitors (nocodazole or aphidicolin), SLF promoted the survival of CCE-27 progenitor cells that respond to the combination of SLF plus IL-3 in vitro and STRCs and LTRCs that are detected in vivo. Taken together, these data show that SLF can directly promote the survival of hematopoietic progenitor cells in the absence of cell division.
authors.affiliation: Biological Carcinogenesis and Development Program, National Cancer Institute-Frederick Cancer Research and Development Center, MD 21702-1201, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Keller
authors.forename: M
authors.initials: M
authors.lastname: Ortiz
authors.forename: F W
authors.initials: FW
authors.lastname: Ruscetti
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells; D002469:Cell Separation / Q000379:methods; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D046508:Culture Techniques / Q000295:instrumentation / Q000379:methods; D004247:DNA / Q000096:biosynthesis; D005434:Flow Cytometry / Q000379:methods; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D016298:Hematopoietic Cell Growth Factors / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D007377:Interleukin-3 / Q000494:pharmacology; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins / Q000494:pharmacology; D019089:Stem Cell Factor; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors
chemical_list: D003115:Colony-Stimulating Factors; D016298:Hematopoietic Cell Growth Factors; D007377:Interleukin-3; D011994:Recombinant Proteins; D019089:Stem Cell Factor; D016179:Granulocyte Colony-Stimulating Factor; D016173:Macrophage Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D004247:DNA; D013936:Thymidine