First published online March 15, 2007
Stem Cells
Vol. 25 No.
6
June 2007, pp.
1586
-1594
doi:10.1634/stemcells.2006-0762; www.StemCells.com
© 2007 AlphaMed Press
TRANSLATIONAL AND CLINICAL RESEARCH |
Murine but Not Human Mesenchymal Stem Cells Generate Osteosarcoma-Like Lesions in the Lung
Susana Aguilara,b,
Emma Nyec,d,
Jerry Chane,
Michael Loebingera,
Bradley Spencer-Denec,d,
Nick Fiske,
Gordon Stampc,d,
Dominique Bonnetb,
Sam M. Janesa
aCentre for Respiratory Research, Rayne Institute, University College London, London, United Kingdom;
bHematopoietic Stem Cell Laboratory and
cExperimental Pathology Laboratory, London Research Institute, Cancer Research UK, London, United Kingdom;
dDepartment of Histopathology and
eInstitute of Reproductive and Developmental Biology, Department of Paediatrics, Imperial College London, Hammersmith Campus, London, United Kingdom
Key Words. Tumor • Mesenchymal stem cell • Lung • Cell therapy • Osteosarcoma
Correspondence: Dominique Bonnet, Ph.D., Hematopoietic Stem Cell Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln's Inn Fields, London WC2A 3PX, U.K. Telephone: 44-207-269-3282; Fax: 44-207-269-3581; e-mail: Dominique.bonnet{at}cancer.org.uk
Received November 30, 2006;
accepted for publication March 7, 2007.
First published online in STEM CELLS EXPRESS March 15, 2007.
Murine mesenchymal stem cells are capable of differentiation into multiple cell types both in vitro and in vivo and may be good candidates to use as cell therapy for diseased or damaged organs. We have previously reported a method of enriching a population of murine MSCs that demonstrated a diverse differentiation potential both in vitro and in vivo. In this study, we show that this enriched population of murine mesenchymal stem cells embolize within lung capillaries following systemic injection and then rapidly expand within, and invade into, the lung parenchyma, forming tumor nodules. These lesions rarely contain cells bearing the immunohistochemical characteristics of lung epithelium, but they do show the characteristics of immature bone and cartilage that resembles exuberant fracture callus or well-differentiated osteosarcoma. Our findings indicate that murine mesenchymal stem cells can behave in a manner similar to tumor cells, with dysregulated growth and aberrant differentiation within the alveolar microenvironment after four passages. We demonstrate that unlike human MSCs, MSCs from different mouse strains can acquire chromosomal abnormalities after only a few in vitro passages. Moreover, other parameters, such as mouse strain used, might also play a role in the induction of these tumors. These findings might be clinically relevant for future stem cell therapy studies.
Disclosure of potential conflicts of interest is found at the end of this article.

Copyright © 2007 by AlphaMed Press.