Granulocyte-macrophage colony-stimulating factor-dependent growth and erythropoietin-induced differentiation of a human cell line MB-02.
Peripheral blood blasts from a patient with acute megakaryoblastic leukemia were placed into liquid cultures with recombinant growth factors. Growth, but not differentiation, was supported by interleukin-3 (IL-3) or granulocyte-macrophage colony-stimulating factor (GM-CSF) for the first 30 days of culture. Sustained growth occurred only with GM-CSF and gave rise to the cell line MB-02, which has been in continuous culture for over 1 year. The cell line retained the surface phenotype of the leukemic megakaryoblasts except for the loss of glycoproteins Ib and IIb/IIIa, which were induced after exposure to phorbol esters. The induction of erythropoiesis occurred when GM-CSF-deprived cells were cultured with erythropoietin (Epo). Well-defined morphologic stages of differentiation ranging from primitive erythroblasts to nuclei-extruding normoblasts were seen. Transforming growth factor-beta inhibited GM-CSF- and Epo-dependent growth, but not erythroid maturation. Indirect immunofluorescence using globin chain-specific monoclonal antibodies detected fetal, but not adult hemoglobin in the uninduced cells. beta-globin was induced and gamma-globin was increased after Epo exposure. Both globin species accumulated in the developing erythrocytes until terminal differentiation. Quantitative S1 analysis of beta-like globin transcripts showed very low levels of epsilon- and beta-globin expression and high levels of gamma-globin expression in cells maintained in GM-CSF. Five days after induction with Epo, epsilon message decreased to barely detectable levels while gamma and beta transcripts increased threefold and 20-fold, respectively. This novel cell line not only retains many characteristics of the leukemic megakaryoblasts from which it was derived, but also can be induced to recapitulate apparent normal erythropoiesis.
Morgan
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Department of Neoplastic Diseases, Hahnemann University, Philadelphia, PA 19102.
Gumucio
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Brodsky
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D015703:Antigens, CD / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D015672:Erythroid Precursor Cells / Q000166:cytology* / Q000276:immunology / Q000648:ultrastructure; D004921:Erythropoietin / Q000494:pharmacology*; D005434:Flow Cytometry; D015870:Gene Expression; D005914:Globins / Q000235:genetics; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007377:Interleukin-3 / Q000494:pharmacology; D007621:Karyotyping; D010703:Phorbol Esters / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D000954:Antigens, Surface; D007377:Interleukin-3; D010703:Phorbol Esters; D016212:Transforming Growth Factor beta; D004921:Erythropoietin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D005914:Globins