Oral epithelial stem cells in tissue maintenance and disease: the first steps in a long journey

The identification and characterization of stem cells is a major focus of developmental biology and regenerative medicine. The advent of genetic inducible fate mapping techniques has made it possible to precisely label specific cell populations and to follow their progeny over time. When combined with advanced mathematical and statistical methods, stem cell division dynamics can be studied in new and exciting ways. Despite advances in a number of tissues, relatively little attention has been paid to stem cells in the oral epithelium. This review will focus on current knowledge about adult oral epithelial stem cells, paradigms in other epithelial stem cell systems that could facilitate new discoveries in this area and the potential roles of epithelial stem cells in oral disease. A better understanding of the adult stem cells found in the oral mucosa should lead to new therapies for mouth disorders, argue two researchers from the University of California, San Francisco, USA. In a review article, Kyle Jones and Ophir Klein discuss the progress made in recent years to identify and characterize oral epithelial stem cells (OESCs) from the tissue that lines the inside of the mouth cavity. Pathological changes in these cells are suspected to underlie various oral diseases. Although scientists have found some molecular markers expressed by OESCs, they have yet to discover genes that are expressed only by these stem cells. This makes tracking the organization and dynamics of OESCs in the body quite difficult, which will eventually be necessary to develop treatments that specifically target OESCs, the authors note.