Human Periodontium-Derived Stem Cells May Give Rise to Carcinoma

The presence of stem cells in the periodontal ligament was supported by several findings where a opulation of mesenchymal stem cells from the periodontal ligament has been isolated and characterizedshowing the ability to express a variety of stromalcells markers. The in vivo regenerative capacity of human periodontium-derived stem cells (PdSCs) was investigated by using 10-week-old athymic nude rats that served as an animal model for cell transplantation. Two animals from the second group (sacrificed at week#6) and all the animals of the third group (N=4) (sacrificed at week#8) presented remarkable tissue enlargements exactly at the operation/test side where PdSCs had been previously transplanted. Histologically, these unusual tissueswere considered to be types of anaplastic squamous epithelial-cell carcinoma.The patients from whom the PdSCs had been extracted, the animal model used, and a possible oncogenic alteration of the PdSCs themselves might all be factors behind the tumors’ initiation. Considering such tumors as cancer stem cells needs further investigations.