Background: The purpose of the study was to examine the effects of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 4 (IL-4) on the bone-marrow-derived human adult mesenchymal stem cells (hMSCs).
Methods: The hMSCs were isolated and cultured with GM-CSF and IL-4 for a period of one month. A single colony of transformed cells was then isolated and their phenotype was characterized by morphology, surface marker expression, and in vivo tumorigenesis.
Results: After one month culture, the transformed mesenchymal cells exhibited the morphology and phenotype similar to those of tumor cells, and also caused multiple fast growing lung deposits when it was injected into immunodeficient mice.
Conclusion: Cytokines-driven malignant transformation of hMSCs may be a useful model for studying signaling pathways initiating malignant transformation of hMSC.