title: Study of oncogenic transformation in ex vivo expanded mesenchymal cells, from paediatric bone marrow.
abstract: OBJECTIVE
  Mesenchymal stromal cells (MSCs) have attracted considerable interest in both the scientific and clinical fields. In order to obtain a sufficient cell number for application, their in vitro expansion is necessary, but during this process their characteristics may be altered and cells may acquire oncogenic properties. We have investigated properties of MSC that may be related to oncogenesis, a critical parameter that has to be evaluated prior to MSC clinical use.
  
  
  METHODS
  We studied the expression of p53, p16, RB, H-RAS and human telomerase reverse transcriptase (hTERT) in MSCs from bone marrow of children diagnosed with idiopathic thrombocytopenic purpura (ITP) and autoimmune neutropenia. The same cells were seeded in soft agar to confirm their anchorage dependence and were karyotypically analysed. Finally, MSCs were subcutaneously transplanted into SCID mice and their ectopic osteogenic as well as tumorigenic potential was evaluated.
  
  
  RESULTS
  We have shown that MSCs derived from bone marrow of children with ITP and autoimmune neutropenia do not undergo transformation, the cells expressed normal levels of p53, p16, RB and H-RAS. Expression of hTERT was undetectable, chromosome content remained stable, and their anchorage dependence was confirmed. In an in vivo model, when MSCs were subcutaneously transplanted into SCID mice, no tumorigenesis was observed.
  
  
  CONCLUSIONS
  These findings suggest that MSCs from bone marrow of children do not have oncogenic properties and, therefore, represent validate candidates for applications in regenerative medicine.
authors.affiliation: Department of Pediatric Hematology-Oncology, University Hospital of Heraklion, University of Crete Medical School, Heraklion, Crete, Greece, andDepartment of Experimental Medicine, University of L'Aquila, L'Aquila, Italy.
authors.forename: D M
authors.initials: DM
authors.lastname: Choumerianou
authors.affiliation: Department of Pediatric Hematology-Oncology, University Hospital of Heraklion, University of Crete Medical School, Heraklion, Crete, Greece, andDepartment of Experimental Medicine, University of L'Aquila, L'Aquila, Italy.
authors.forename: H
authors.initials: H
authors.lastname: Dimitriou
authors.affiliation: Department of Pediatric Hematology-Oncology, University Hospital of Heraklion, University of Crete Medical School, Heraklion, Crete, Greece, andDepartment of Experimental Medicine, University of L'Aquila, L'Aquila, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Perdikogianni
authors.affiliation: Department of Pediatric Hematology-Oncology, University Hospital of Heraklion, University of Crete Medical School, Heraklion, Crete, Greece, andDepartment of Experimental Medicine, University of L'Aquila, L'Aquila, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Martimianaki
authors.affiliation: Department of Pediatric Hematology-Oncology, University Hospital of Heraklion, University of Crete Medical School, Heraklion, Crete, Greece, andDepartment of Experimental Medicine, University of L'Aquila, L'Aquila, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Riminucci
authors.affiliation: Department of Pediatric Hematology-Oncology, University Hospital of Heraklion, University of Crete Medical School, Heraklion, Crete, Greece, andDepartment of Experimental Medicine, University of L'Aquila, L'Aquila, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Kalmanti
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000187:drug effects / Q000473:pathology*; D001857:Bone Matrix / Q000187:drug effects / Q000473:pathology; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D016147:Genes, Tumor Suppressor; D006801:Humans; D007223:Infant; D007621:Karyotyping; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000201:enzymology / Q000473:pathology*; D051379:Mice; D016513:Mice, SCID; D009857:Oncogenes; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017154:Stromal Cells / Q000187:drug effects / Q000473:pathology; D019098:Telomerase / Q000235:genetics / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2; C509186:TERT protein, human; D019098:Telomerase