title: Mesenchymal stem cells with rhBMP-2 inhibits the growth of canine osteosarcoma cells.
abstract: BACKGROUND
  The bone morphogenetic proteins (BMPs) belong to a unique group of proteins that includes the growth factor TGF-β. BMPs play important roles in cell differentiation, cell proliferation, and inhibition of cell growth. They also participate in the maturation of several cell types, depending on the microenvironment and interactions with other regulatory factors. Depending on their concentration gradient, the BMPs can attract various types of cells and act as chemotactic, mitogenic, or differentiation agents. BMPs can interfere with cell proliferation and the formation of cartilage and bone. In addition, BMPs can induce the differentiation of mesenchymal progenitor cells into various cell types, including chondroblasts and osteoblasts. The aim of this study was to analyze the effects of treatment with rhBMP-2 on the proliferation of canine mesenchymal stem cells (cMSCs) and the tumor suppression properties of rhBMP-2 in canine osteocarcoma (OST) cells. Osteosarcoma cell lines were isolated from biopsies and excisions of animals with osteosarcoma and were characterized by the Laboratory of Biochemistry and Biophysics, Butantan Institute. The mesenchymal stem cells were derived from the bone marrow of canine fetuses (cMSCs) and belong to the University of São Paulo, College of Veterinary Medicine (FMVZ-USP) stem cell bank. After expansion, the cells were cultured in a 12-well Transwell system; cells were treated with bone marrow mesenchymal stem cells associated with rhBMP2. Expression of the intracytoplasmic and nuclear markers such as Caspase-3, Bax, Bad, Bcl-2, Ki-67, p53, Oct3/4, Nanog, Stro-1 were performed by flow citometry.
  
  
  RESULTS
  We evaluated the regenerative potential of in vitro treatment with rhBMP-2 and found that both osteogenic induction and tumor regression occur in stem cells from canine bone marrow. rhBMP-2 inhibits the proliferation capacity of OST cells by mechanisms of apoptosis and tumor suppression mediated by p53.
  
  
  CONCLUSIONS
  We propose that rhBMP-2 has great therapeutic potential in bone marrow cells by serving as a tumor suppressor to increase p53 and the pro-apoptotic proteins Bad and Bax, as well as by increasing the activity of phosphorylated caspase 3.
  
  
  METHODS
  Canine bone marrow mesenchymal stem cells associated with rhBMP2 in canine osteosarcoma treatment: "in vitro" study.
authors.affiliation: Department of Surgery, Faculty of the Veterinary Medicine and Zootecny, São Paulo University, São Paulo, Brazil. roseeli@usp.br
authors.forename: Rose Eli Grassi
authors.initials: RE
authors.lastname: Rici
authors.forename: Dayane
authors.initials: D
authors.lastname: Alcântara
authors.forename: Paula
authors.initials: P
authors.lastname: Fratini
authors.forename: Cristiane Valverde
authors.initials: CV
authors.lastname: Wenceslau
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Ambrósio
authors.forename: Maria Angelica
authors.initials: MA
authors.lastname: Miglino
authors.forename: Durvanei Augusto
authors.initials: DA
authors.lastname: Maria
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells; D055396:Bone Morphogenetic Protein 2 / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018920:Coculture Techniques; D004285:Dogs; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000378:metabolism*; D012516:Osteosarcoma / Q000378:metabolism*; D011994:Recombinant Proteins
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D011994:Recombinant Proteins