Dormancy in the Stem Cell Niche

The document from March 19, 2012, reviews the concept of dormancy in stem cell niches, particularly focusing on dormant hematopoietic stem cells (HSCs) that divide infrequently. It discusses the presence of dormant stem cells in various tissues, including the epidermis, intestinal epithelium, and neuroepithelium, and the implications for therapeutic developments. The review describes methods to identify slow-dividing stem cells and the potential for specific niches that maintain stem cell dormancy. It also explores the complexity within stem cell pools in different tissues and raises the possibility of dormant subpopulations within cancer stem cells (CSCs), suggesting that understanding the control of dormancy could lead to better therapies for diseases and aging. The document highlights the role of osteoblastic cells in the HSC niche, the identification of stem cells in the intestine, colon, and skin, and the dynamics of hair follicle stem cells. It concludes with the challenges in targeting tumor-initiating cells and the potential of in vivo imaging techniques for studying transplanted stem and progenitor cells.