Stem Cell Heterogeneity and Plasticity in Epithelia

The 2015 review "Stem Cell Heterogeneity and Plasticity in Epithelia" discussed the existence of multiple stem cell compartments within individual epithelia, their significant plasticity in response to tissue damage, transplantation, or tumor development, and the role of the epithelial niche and transcription factor networks in regulating stem cell behavior. The authors noted the development of in vitro tissue substitutes for better data integration from human and mouse models. They emphasized the heterogeneity of stem cells within individual epithelia, with different stem cell populations identified in various parts of the epidermis and hair follicle. The study also revealed that tumor growth is driven by the expansion of genetically altered clones that adapt and proliferate in tumor niches, and not derived from long-lived mutant stem cells. The researchers found evidence for the existence of cancer stem cells in epithelial tumors. The document also discussed the role of fibroblasts, immune cells, bacteria, and transcription and epigenetic factors in maintaining homeostasis and contributing to disease progression. The study highlighted the development of a method called FISSEQ for growing epithelial organoids from single cells and recreating the differentiated lineages present in normal tissue, including hair follicles.