title: In vitro gene and chromosome characterization of expanded bone marrow mesenchymal stem cells for musculo-skeletal applications.
abstract: OBJECTIVE
  A number of studies have shown the role of expanded Bone Marrow-derived Mesenchymal Stem Cells in the repair and regeneration of musculo-skeletal tissues. The current European regulations define in vitro expanded cells for clinical purposes as substantially manipulated and include them in the class of Advanced-Therapy Medicinal Products to be manufactured in compliance with current Good Manufacturing Practice. Among the characteristics that such cells should display, genomic stability has recently become a major safety concern. The aim of this study is to perform a chromosomal and genetic characterization of Bone Marrow-derived Mesenchymal Stem Cells expanded in compliance with Good Manufacturing Practice for a potential clinical use in orthopaedics.
  
  
  METHODS
  Mesenchymal Stem Cells, isolated from bone marrow, were expanded for six weeks in compliance with current Good Manufacturing Practice. DNA profiling analyses were applied to test cross-contamination absence. Genomic stability was evaluated by means of karyotyping, sequencing of TP53, p21/CDKN1A and MDM2 genes and the expression analysis of c-MYC and H-RAS oncogenes, p21/CDKN1A, TP53, p16/CDKN2A, RB1 and p27/CDKN1B tumor suppressor genes and hTERT gene.
  
  
  RESULTS
  The DNA profiling analysis showed a unique genetic profile for each Mesenchymal Stem Cell culture, indicating the absence of cross-contamination. Karyotyping evidentiated some chromosomal abnormalities within the 10% limit set by the Cell Products Working Party review, except for one patient. In all cases, the molecular biology analyses did not revealed DNA point mutations, acquisition or changes in gene expression. hTERT levels were undetectable.
  
  
  CONCLUSIONS
  Cultured Mesenchymal Stem Cells do not seem to be prone to malignant transformation. In fact, although some chromosomal aberrations were found, molecular biology analyses demonstrated that the expansion phase did not induce the acquisition of de novo genetic changes.
authors.affiliation: RAMSES Laboratory, Research Innovation Technology Department, Rizzoli Orthopaedic Institute, Bologna, Italy. livia.roseti@ior.it.
authors.forename: L
authors.initials: L
authors.lastname: Roseti
authors.forename: M
authors.initials: M
authors.lastname: Serra
authors.forename: F
authors.initials: F
authors.lastname: Canella
authors.forename: C
authors.initials: C
authors.lastname: Munno
authors.forename: A
authors.initials: A
authors.lastname: Tosi
authors.forename: M
authors.initials: M
authors.lastname: Zuntini
authors.forename: M
authors.initials: M
authors.lastname: Pandolfi
authors.forename: L
authors.initials: L
authors.lastname: Sangiorgi
authors.forename: P
authors.initials: P
authors.lastname: Biso
authors.forename: M C
authors.initials: MC
authors.lastname: Pittalis
authors.forename: C
authors.initials: C
authors.lastname: Bini
authors.forename: S
authors.initials: S
authors.lastname: Pelotti
authors.forename: A
authors.initials: A
authors.lastname: Gasbarrini
authors.forename: L
authors.initials: L
authors.lastname: Boriani
authors.forename: A
authors.initials: A
authors.lastname: Bassi
authors.forename: B
authors.initials: B
authors.lastname: Grigolo
mesh_terms: D000328:Adult; D001854:Bone Marrow Cells / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007621:Karyotyping / Q000379:methods; D008297:Male; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D009140:Musculoskeletal Diseases / Q000235:genetics* / Q000473:pathology / Q000628:therapy*; D055815:Young Adult