Endometrial Stem/Progenitor Cells

Purpose of Review To summarize endometrial stem/progenitor cell biology and endometrial cancer stem cells. Recent Findings The subject is relatively new that only about 15 years ago, colony-forming units, as putative endometrial stem/progenitor cells, have been demonstrated in an endometrial sample. Earlier and some recent studies have justifiably focused on endometriosis as the serious gynecologic problem of women. However, on the side of endometrial stem cells research, many current studies are still working on in vitro methods, and the majority of the rest are on animal models. Reported cells as endometrial stem/progenitor cell populations have been heterogeneous such as endometrial mesenchymal stem cells, endometrial epithelial progenitor cells, and side population cells. After the recognition of putative endometrial stem cells, quite a few stem cell markers have been identified. Thereafter, cancer stem cell speculations have raised; in endometrial cancer, CD133+ and CXCR4+ cells, with potential cancer stem cell characteristics, have been shown to have higher antineoplastic resistance than that of other cell populations. Endometrial mesenchymal stem cells have plasticity characteristics and may differentiate into mature cells other than endometrium. On the other hand, bone marrow-derived stem cells can differentiate into endometrial cells. Since the endometrial stem/progenitor cells are easy to access, they can be an attractive source for regenerative medicine studies. Even though many markers have been identified for endometrial stem cells, more specific and sensitive marker combinations are yet to be defined for endometrial cancer stem cell in order to aim for more effective treatment approaches.