title: Leukemia-differentiating activity expressed by the human melanoma cell line LD-1.
abstract: We have identified a leukemia-differentiating activity (LDA) in medium conditioned by the LD-1 melanoma, a G-CSF secreting human tumor line. Partially-purified LDA induces HL-60 cells to produce superoxide, become phagocytic, and to develop macrophage-like morphology and surface markers. The LDA markedly suppresses clonal growth in agar of HL-60 cells, and cells of the human myeloid leukemia lines PBL 985 and K562, but does not suppress clonal growth of the B-lymphoblast lines Raji and Daudi. The molecular weight of this material is approx. 40,000 daltons. It can be separated from the bulk of the colony stimulating activity on phenyl sepharose chromatography. The LDA is not neutralized by antibodies to G-CSF, GM-CSF, IFN alpha, IFN gamma, TNF, urokinase, and tissue plasminogen activator, and is not inhibited by preincubation with aprotinin. The LDA in conditioned medium may be different from previously described differentiating factors, and may represent an additional class of human growth regulators.
authors.affiliation: Department of Medicine, University of Alabama, Birmingham 35294.
authors.forename: M B
authors.initials: MB
authors.lastname: Lilly
authors.forename: A S
authors.initials: AS
authors.lastname: Kraft
mesh_terms: D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D003470:Culture Media / Q000032:analysis; D006131:Growth Inhibitors / Q000302:isolation & purification / Q000502:physiology; D006133:Growth Substances / Q000302:isolation & purification* / Q000502:physiology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D015470:Leukemia, Myeloid, Acute / Q000473:pathology; D008546:Melanoma, Experimental / Q000378:metabolism*; D008970:Molecular Weight; D014407:Tumor Cells, Cultured / Q000378:metabolism* / Q000473:pathology; D014410:Tumor Stem Cell Assay
chemical_list: D003470:Culture Media; D006131:Growth Inhibitors; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; C047526:leukemia growth-promoting factor