Downregulation of Osteoblast Markers and Induction of the Glial Fibrillary Acidic Protein by Oncostatin M in Osteosarcoma Cells Require PKCδ and STAT3

Autor: Frédéric Blanchard, Dominique Heymann, Françoise Rédini, Céline Chipoy, Gilbert Pradal, Séverine Couillaud, Caroline Colombeix, Martine Berreur, François M. Vallette
Rok vydání: 2004
Předmět:
Bone sialoprotein
Time Factors
Endocrinology
Diabetes and Metabolism
Cellular differentiation
Anthraquinones
Cell Cycle Proteins
Mesoderm
Orthopedics and Sports Medicine
Enzyme Inhibitors
Protein Kinase C
Osteosarcoma
Microscopy
Confocal
biology
Glial fibrillary acidic protein
Reverse Transcriptase Polymerase Chain Reaction
Stem Cells
Oncostatin M
Cell Differentiation
Osteoblast
Immunohistochemistry
DNA-Binding Proteins
Protein Kinase C-delta
medicine.anatomical_structure
Signal Transduction
Cyclin-Dependent Kinase Inhibitor p21
STAT3 Transcription Factor
musculoskeletal diseases
Sialoglycoproteins
Blotting
Western
Osteocalcin
Down-Regulation
Bone Marrow Cells
Transfection
Models
Biological
Bone and Bones
Cell Line
Tumor
Glial Fibrillary Acidic Protein
Nitriles
Butadienes
medicine
Animals
Integrin-Binding Sialoprotein
Regeneration
RNA
Messenger
Cell Proliferation
Inflammation
Osteoblasts
Dose-Response Relationship
Drug
Interleukin-6
Cell growth
fungi
Mesenchymal stem cell
DNA
Alkaline Phosphatase
medicine.disease
Rats
Microscopy
Electron
Trans-Activators
biology.protein
Cancer research
Thymidine
Zdroj: Journal of Bone and Mineral Research. 19:1850-1861
ISSN: 0884-0431
DOI: 10.1359/jbmr.040817
Popis: The effects of OSM on proliferation and differentiation of osteosarcoma and nontransformed osteoblasts were analyzed. OSM downregulates osteoblast markers but induces the glial fibrillary acidic protein by the combined activation of PKCδ and STAT3, offering new lines of therapeutic investigations. Introduction: Oncostatin M (OSM) is a multifunctional cytokine of the interleukin-6 family implicated in embryonic development, differentiation, inflammation, and regeneration of various tissues, mainly the liver, bone, and the central nervous and hematopoietic systems. One particularity of OSM relies on its growth inhibitory and pro-differentiating effects on a variety of tumor cell lines such as melanoma, providing arguments for a therapeutic application of OSM. The objective of this study was to analyze the effects of OSM on osteosarcoma cell lines proliferation and differentiation. Materials and Methods: Proliferation was analyzed by3H thymidine incorporation. Differentiation was analyzed by semiquantitative RT-PCR and immunocytochemistry for various markers. Alizarin red S staining was used to evaluate bone nodule formation. Morphological changes were studied by confocal and electron microscopy. Western blotting, kinases inhibitors, and dominant negative STAT3 were used to identified the signaling pathways implicated. Results: OSM inhibits the growth of rat osteosarcoma cell lines as well as normal osteoblasts, in correlation with induction of the cyclin-dependent kinases inhibitor p21WAF1. However, OSM reduces osteoblast markers such as alkaline phosphatase, osteocalcin, and bone sialoprotein, leading to strong inhibition of mineralized nodule formation. This inhibitory effect is restricted to mature osteoblasts and differentiated osteosarcoma because OSM effectively stimulates osteoblast markers and bone nodule formation in early, but not late, bone marrow mesenchymal stem cell (BMSC) cultures. In osteosarcoma cells or BMSC, OSM induces expression of the glial fibrillary acidic protein (GFAP) as well as morphological and ultrastructural changes, for example, elongated shape and bundles of microfilaments in cell processes. Rottlerin (PKCδ inhibitor), and to a lesser degree UO126 (MEK/ERK inhibitor), prevents the loss of osteoblastic markers by OSM, whereas dominant negative STAT3 prevents GFAP induction. Conclusions: These results highlight the particular gene expression profile of OSM-treated osteosarcoma cells and BMSCs, suggesting either a osteocytic or a glial-like phenotype. Together with the implication of PKCδ, ERK1/2, and STAT3, these results offer new lines of investigations for neural cell transplantation and osteosarcoma therapy.
Databáze: OpenAIRE
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