Molecular analysis of the hematopoiesis supporting osteoblastic cell line U2-OS

J M Nelissen, R Torensma, M Pluyter, G J Adema, R A Raymakers, Y van Kooyk, C G Figdor

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OBJECTIVE: Osteoblasts play an important role in regulating hematopoiesis in the bone marrow. Here we show that U2-OS, a widely used osteoblastic cell line derived from an osteosarcoma, has the capacity to support proliferation of human hematopoietic progenitor cells in vitro. In this study, U2-OS cells are characterized at the molecular level to unravel the molecular mechanisms underlying the support of hematopoiesis.

MATERIALS AND METHODS: U2-OS was analyzed in great detail using RT-PCR and flow cytometry. In addition, a cDNA library was constructed and randomly sequenced to obtain insight in the repertoire of expressed molecules.

RESULTS: A broad panel of growth factors and cytokines is expressed by U2-OS. TGF-beta, GM-CSF, c-kit ligand, and IL-7 are produced constitutively and IL-1beta, IL-6, IL-8, TNF-alpha, IFN-gamma, and MIP1-alpha are upregulated upon stimulation. In addition to those, mRNAs of the CC chemokine LARC and leukemia inhibitory factor were identified. U2-OS cells express high levels of beta1-integrins at the cell surface: VLA-2, VLA-3, VLA-4, VLA-5, VLA-6, and the integrin alphavbeta3. Besides integrins, ALCAM and NCAM are detected on the cell surface of U2-OS. Interestingly, we show that CD34(+) progenitor cells expressing ALCAM are highly proliferative when compared with CD34(+) ALCAM(low) cells, hinting at a role for ALCAM in anchoring progenitor cells to the bone marrow stroma. Interestingly, random sequencing of an U2-OS cDNA library yielded almost 10% of novel cDNAs with a potential role in hematopoiesis. The involvement of these novel molecules in hematopoiesis is an interesting target for future investigations.

CONCLUSIONS: We conclude that U2-OS supports outgrowth of hematopoietic progenitor cells and accordingly expresses adhesion molecules and growth factors and a number of novel, as yet uncharacterized potentially interesting genes.

Original languageEnglish
Pages (from-to)422-32
Number of pages11
JournalExperimental Hematology
Issue number4
Publication statusPublished - Apr 2000


  • Activated-Leukocyte Cell Adhesion Molecule/biosynthesis
  • Antigens, CD/biosynthesis
  • Antigens, CD34/biosynthesis
  • Antigens, Differentiation, T-Lymphocyte/biosynthesis
  • Cell Adhesion Molecules/biosynthesis
  • Cell Division/genetics
  • Cell Membrane/metabolism
  • Cells, Cultured
  • Coculture Techniques
  • Cytokines/biosynthesis
  • Flow Cytometry
  • Gene Library
  • Growth Substances/biosynthesis
  • Hematopoiesis/physiology
  • Hematopoietic Stem Cells/cytology
  • Humans
  • Hyaluronan Receptors/biosynthesis
  • Integrins/biosynthesis
  • Ionomycin/pharmacology
  • Osteoblasts/metabolism
  • Osteosarcoma/metabolism
  • RNA, Messenger/biosynthesis
  • Receptors, CXCR3
  • Receptors, Cell Surface/biosynthesis
  • Receptors, Chemokine/biosynthesis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tetradecanoylphorbol Acetate/pharmacology

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