title: Bone morphogenetic protein-2 promotes the haptotactic migration of murine osteoblastic and osteosarcoma cells by enhancing incorporation of integrin beta1 into lipid rafts.
abstract: Cell migration is essential for both organogenesis and tumor progression. Bone morphogenetic proteins (BMPs) are reported to be critical for not only bone formation but also tumor invasion. Here, we found that treatment with recombinant human BMP-2 (rhBMP-2) enhanced the haptotactic response of murine osteoblastic MC3T3-E1 and osteosarcoma Dunn cells to various extracellular matrix (ECM) components, including fibronectin, type I collagen, and laminin-1. Function-blocking antibody against integrin alpha5beta1 partially inhibited haptotaxis to fibronectin, suggesting that the response was propagated via these integrins. rhBMP-2 slightly increased the expression level of integrin beta1, and enhanced the speed of cell spreading on fibronectin, focal adhesion formation and phosphorylation of focal adhesion kinase (FAK) at Tyr397. By means of sucrose gradient flotation, incorporation of integrin beta1 in fractions of detergent (CHAPS) resistant membrane was increased when the cells were treated with rhBMP-2. Further, treatment with methyl-beta-cyclodextrin to deplete membrane cholesterol abrogated the effect of rhBMP-2 on haptotaxis, and exogenously added cholesterol reversed this inhibitory effect. Collectively, these results provide insights into the mechanism by which BMP signaling enhances cell migration by modulating fibronectin-integrin beta1 signaling via cholesterol enriched membrane microdomains, lipid rafts.
authors.affiliation: Department of Biology, Osaka Medical Center for Cancer and Cardiovascular Diseases, 1-3-3 Nakamichi, Higashinari-ku, Osaka 537-8511, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Sotobori
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ueda
authors.forename: Akira
authors.initials: A
authors.lastname: Myoui
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Yoshioka
authors.forename: Manando
authors.initials: M
authors.lastname: Nakasaki
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Itoh
mesh_terms: D016475:3T3 Cells; D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D001859:Bone Neoplasms / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D022001:Focal Adhesions / Q000187:drug effects; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism*; D021962:Membrane Microdomains / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D012516:Osteosarcoma / Q000378:metabolism / Q000473:pathology; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
chemical_list: C525718:BMP2 protein, human; C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D019012:Integrin beta1; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D051416:Focal Adhesion Protein-Tyrosine Kinases