Researchers have shown dental epithelial stem cells can differentiate into non-dental organs under the right conditions and have demonstrated this in a mouse model where they successfully generated cells capable of forming mammary ducts and milk producing cells when transplanted into mammary glands.
Dental stem cells were harvested from the growing incisors of young mice. Cells of mammary origin were removed, and the harvested dental epithelial stem cells were injected into the mammary glands of mice along with mammary epithelial cells. The cells were tracked using genetic, molecular, and imaging tools and were found to have differentiated and were contributing to the regeneration of tissue in the mammary gland fat pad.
Just as dental epithelial stem cells can differentiate into all dental cell types, they are also capable of differentiating into all types of mammary gland cells. They were even found to have differentiated into cells capable of producing milk.
The research team, led by Thimios Mitsiadis, professor at the Institute of Oral Biology of the University of Zurich, is the first to demonstrate that dental epithelial stem cells could potentially be used for tissue regeneration in other parts of the body.
A second round of experiments were conducted that involved the introduction of dental epithelial stem cells without mammary epithelial cells. The cells were found to have differentiated into cells capable of forming small ductal systems, although the researchers found that in some of the mice it resulted in the formation of cysts. Other studies conducted by the researchers using different types of stem cells of non-mammary origin did not result in differentiation into duct-producing cells without the co-introduction of mammary epithelial cells. The researchers suggest this level of plasticity could be unique to dental epithelial cells.
If the findings can be replicated in humans, this could serve as a new treatment for regenerating breast tissue following the removal of tumors and serve as an alternative to other forms of tissue regeneration in humans.
The study is detailed in the paper – Dental Epithelial Stem Cells as a Source for Mammary Gland Regeneration and Milk Producing Cells In Vivo – which was recently published in the journal Cells. DOI: 0.3390/cells8101302