title: Long-term culture of chronic myelogenous leukemia marrow cells on stem cell factor-deficient stroma favors benign progenitors.
abstract: Long-term culture of marrow from patients with chronic myelogenous leukemia (CML) has been reported to favor the outgrowth of bcr/abl- progenitor cells in some patients. We examined the effect of the presence of soluble or transmembrane forms of stem cell factor (SCF) in long-term cultures of CML marrow. CD34-enriched cells from CML patients in advanced chronic phase or accelerated phase were plated on immortalized fetal liver stromal cells from homozygous SCF-deficient SI/SI mice (SI/SI4) with or without the addition of soluble human SCF, SI/SI4 cells expressing high levels of the transmembrane form of human SCF (SI/SIh220), or primary human allogeneic stroma. Cells were removed from cultures and plated weekly in colony assays. The clonagenic cell output from cultures completely lacking SCF was lower over the first 2 to 3 weeks, but by 5 weeks was similar to the clonagenic cell output from the other culture conditions. Analysis of bcr/abl transcripts from individual colonies showed a lower percentage of malignant progenitors present in long-term cultures completely deficient in SCF than under the other culture conditions, particularly compared with primary human stroma-containing long-term cultures. SCF may specifically favor malignant versus benign progenitor cells present in the marrow of CML patients, and an abnormal proliferative response to SCF in very primitive cells may be an underlying defect in the pathophysiology of this disease.
authors.affiliation: Children's Hospital Medical Center, Cincinnati, OH.
authors.forename: R
authors.initials: R
authors.lastname: Agarwal
authors.forename: S
authors.initials: S
authors.lastname: Doren
authors.forename: B
authors.initials: B
authors.lastname: Hicks
authors.forename: C E
authors.initials: CE
authors.lastname: Dunbar
mesh_terms: D000328:Adult; D001483:Base Sequence; D001853:Bone Marrow / Q000473:pathology*; D002455:Cell Division; D003238:Connective Tissue / Q000502:physiology; D016044:Fusion Proteins, bcr-abl / Q000032:analysis; D015973:Gene Expression Regulation, Leukemic; D006410:Hematopoiesis; D016298:Hematopoietic Cell Growth Factors / Q000172:deficiency / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000502:physiology*; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology*; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000502:physiology; D019009:Proto-Oncogene Proteins c-kit; D020794:Receptor Protein-Tyrosine Kinases / Q000502:physiology; D016184:Receptors, Colony-Stimulating Factor / Q000502:physiology; D012641:Selection, Genetic; D019089:Stem Cell Factor; D013997:Time Factors; D014407:Tumor Cells, Cultured; D014410:Tumor Stem Cell Assay
chemical_list: D016298:Hematopoietic Cell Growth Factors; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D016184:Receptors, Colony-Stimulating Factor; D019089:Stem Cell Factor; D019009:Proto-Oncogene Proteins c-kit; D020794:Receptor Protein-Tyrosine Kinases; D016044:Fusion Proteins, bcr-abl