title: Humoral and cell surface interactions during gamma-irradiation leukemogenesis in vitro.
abstract: Gamma-irradiation of plateau phase cultures of the clonal murine bone marrow stromal cell line D2XRII followed by cocultivation of a clonal interleukin 3 (IL-3) (granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent hematopoietic progenitor cell line FDC-P1JL26 results in a significant increase in "cobblestone islands" of attachment and emergence of subclonal factor-independent malignant sublines. Biochemical purification of conditioned medium from irradiated D2XRII cells yielded a 75,000-dalton glycoprotein termed leukemogenic stromal factor (LSF) that was neutralized by a polyclonal antiserum to murine macrophage colony-stimulating factor (M-CSF). A monoclonal antibody to the murine M-CSF receptor (c-fms) neutralized the biological activity of this molecule in a manner comparable to its effect on recombinant human or murine M-CSF. FDC-P1JL26 parent cells were positive for Ly5, MEL-14, mGR, VLA-4, PGP-1 (CD44), and Thy1.2. After culture in LSF, Thy1.2, MEL-14, and mGR became undetectable; however, significant cell surface MAC-1 antigen and c-fms (M-CSF receptor) were expressed. Neither line was positive for Ly6, Ly22, I-CAM-1, or B220 antigen. LSF-precultured FDC-P1JL26 cells transferred as single cells to microwell culture with 5000-cGy-irradiated D2XRII cells revealed a 60-fold increase in frequency of cobblestone island formation and evolution of factor-independent subclones compared to the parent line. Both parent and LSF-precultured cells became factor independent at a 100-fold lower frequency if kept in suspension in LSF in the absence of stromal cells. Antiserum to M-CSF or monoclonal antibody to the murine M-CSF receptor (c-fms) did not inhibit or displace cobblestone island formation by either clone of FDC-P1 on irradiated stromal cells indicating a mechanism of binding not involving the M-CSF receptor. However, anti-serum to the M-CSF receptor inhibited growth of one factor-independent subclone. In separate studies, a subclone of IL-3-dependent 32Dc13 cells, expressing the transfected murine c-fms protooncogene but not the parent 32Dc13 cell line or another subclone expressing the transfected gene for the human M-CSF receptor, showed adherence and became factor independent when cocultivated with irradiated D2XRII stromal cells. Thus, irradiated stromal cells bind M-CSF receptor-positive hematopoietic progenitor cells and induce c-fms-dependent factor-independent tumorigenic subclones. The cellular interactions in this model may be relevant to gamma-irradiation leukemogenesis in vivo.
authors.affiliation: Department of Radiation Oncology, University of Massachusetts Medical Center, Worcester 01655.
authors.forename: J
authors.initials: J
authors.lastname: Greenberger
authors.forename: J
authors.initials: J
authors.lastname: Leif
authors.forename: D
authors.initials: D
authors.lastname: Crawford
authors.forename: P
authors.initials: P
authors.lastname: Anklesaria
authors.forename: D
authors.initials: D
authors.lastname: English
authors.forename: M
authors.initials: M
authors.lastname: Sakakeeny
authors.forename: J
authors.initials: J
authors.lastname: Rubin
authors.forename: J
authors.initials: J
authors.lastname: Pierce
authors.forename: R
authors.initials: R
authors.lastname: Shadduck
authors.forename: T J
authors.initials: TJ
authors.lastname: FitzGerald
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001853:Bone Marrow / Q000502:physiology / Q000528:radiation effects*; D001854:Bone Marrow Cells; D002450:Cell Communication / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D002469:Cell Separation; D002478:Cells, Cultured; D005453:Fluorescence; D005720:Gamma Rays; D006023:Glycoproteins / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006410:Hematopoiesis / Q000187:drug effects / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology / Q000528:radiation effects; D007377:Interleukin-3 / Q000494:pharmacology; D007942:Leukemia, Experimental / Q000209:etiology* / Q000473:pathology; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D016177:Macrophage-1 Antigen / Q000032:analysis; D051379:Mice; D009381:Neoplasms, Radiation-Induced / Q000209:etiology* / Q000473:pathology; D010641:Phenotype; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000032:analysis / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; D006023:Glycoproteins; D007377:Interleukin-3; D016177:Macrophage-1 Antigen; D016173:Macrophage Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D016186:Receptor, Macrophage Colony-Stimulating Factor