title: Bone marrow matrix promotes differentiation and prolongs the cell cycle of U-937 cells.
abstract: The extracellular matrix influences the growth and differentiation of a variety of cell types. In this study, the effects of bone marrow extracellular matrix on U-937 cells, a human histiocytic lymphoma cell line, were assessed. Sixty percent of U-937 cells adhered to extracellular matrix, whereas only 1% adhered to uncoated plastic. U-937 cells grown on extracellular matrix released significantly more lysozyme into the medium (8.3 +/- 0.3 micrograms/10(6) cells) compared to those grown on plastic (4.2 +/- 0.5 micrograms/10(6) cells). FMLP (f-met-leu-phe) receptor expression was also enhanced suggesting a more mature phenotype in cells grown on matrix (2980 cpm/10(6) cells vs 230 cpm/10(6) cells on plastic). Furthermore, bone marrow extracellular matrix inhibited proliferation of U-937 cells. After four days in culture, there was a 65% inhibition of cell growth in matrix-coated flasks compared to uncoated flasks. Since an arrest in G0/G1 usually precedes mammalian cell differentiation, DNA histograms were performed on U-937 cells grown on matrix to detect such an arrest. However, the cell cycle distribution of U-937 cells grown on extracellular matrix or uncoated plastic for various time periods was similar. In contrast, bromodeoxyuridine pulse labeling revealed approximately a 5 hr prolongation in cycle length in cells grown on extracellular matrix. We conclude that bone marrow extracellular matrix induced macrophage-like differentiation and inhibited proliferation of U-937 cells with a prolongation of the cell cycle that was not G0/G1 phase specific.
authors.affiliation: Department of Medicine, University of Minnesota Medical School, Minneapolis.
authors.forename: H F
authors.initials: HF
authors.lastname: Hamdan
authors.forename: S D
authors.initials: SD
authors.lastname: Luikart
mesh_terms: D001853:Bone Marrow / Q000502:physiology*; D002448:Cell Adhesion; D002450:Cell Communication; D002453:Cell Cycle; D002454:Cell Differentiation; D002460:Cell Line; D005109:Extracellular Matrix / Q000502:physiology; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse; D009113:Muramidase / Q000378:metabolism; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000378:metabolism; D044042:Receptors, Formyl Peptide; D011971:Receptors, Immunologic / Q000378:metabolism
chemical_list: D044042:Receptors, Formyl Peptide; D011971:Receptors, Immunologic; D009240:N-Formylmethionine Leucyl-Phenylalanine; D009113:Muramidase