Identification and characterisation of human endometrial stem/progenitor cells.

The human endometrium is a dynamic, cyclically regenerating tissue. Because adult stem cells are present in other regenerative tissues, a clonal analysis of purified endometrial epithelial and stromal cells derived from hysterectomy tissue was undertaken, as a first attempt to identify and characterise endometrial stem/progenitor cells. Rare populations of epithelial and stromal cells were clonogenic. Only those cells initiating large clones, 0.09% of epithelial cells and 0.02% of stromal cells, are likely to be endometrial stem/progenitor cells.