title: Hematopoietic precursors resistant to treatment with 4-hydroperoxycyclophosphamide: requirement for an interaction with marrow stroma in addition to hematopoietic growth factors for maximal generation of colony-forming activity.
abstract: We tested the ability of CD34+lin- precursor cells isolated from marrow after treatment with 4-hydroperoxycyclophosphamide (4HC) to generate colony-forming cells (CFC). In liquid cultures, recombinant human stem cell factor (SCF), in combination with interleukin-1 (IL-1), IL-3, IL-6, granulocyte-macrophage colony-stimulating factor, or granulocyte colony-stimulating factor caused untreated, but not 4HC-treated, CD34+lin- cells to form CFC. However, generation of CFC from CD34+lin- cells treated with 60 micrograms/mL of 4HC was possible in the presence of an irradiated allogeneic stromal cell layer. This generation was increased when combinations of hematopoietic growth factors including SCF and IL-3 were added. Maximal generation of CFC was seen after 11 to 21 days of culture. At that time, generation of CFC from CD34+lin- 4HC-treated cells equalled that from untreated cells. The phenotype of these 4HC-resistant CD34+lin- precursors was also further defined as CD38-. These studies show that the generation of CFC from the 4HC-resistant, highly immature population of CD34+lin- cells requires an as yet undefined interaction with marrow stroma in addition to known hematopoietic growth factors.
authors.affiliation: Division of Clinical Research, Fred Hutchinson Cancer Research Center, Seattle, WA 98104.
authors.forename: S D
authors.initials: SD
authors.lastname: Rowley
authors.forename: C
authors.initials: C
authors.lastname: Brashem-Stein
authors.forename: R
authors.initials: R
authors.lastname: Andrews
authors.forename: I D
authors.initials: ID
authors.lastname: Bernstein
mesh_terms: D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34; D000943:Antigens, Differentiation / Q000032:analysis; D001853:Bone Marrow / Q000187:drug effects; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D003520:Cyclophosphamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D006410:Hematopoiesis / Q000187:drug effects*; D016298:Hematopoietic Cell Growth Factors / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D066298:In Vitro Techniques; D008562:Membrane Glycoproteins; D019089:Stem Cell Factor; D013997:Time Factors
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D000943:Antigens, Differentiation; D016298:Hematopoietic Cell Growth Factors; D008562:Membrane Glycoproteins; D019089:Stem Cell Factor; D003520:Cyclophosphamide; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1; C011272:perfosfamide