Glandular Stem Cells (GSCs): Stem Cells in Glandular Organs

The interaction between epithelium and stroma determines the ontogenesis and pathogenesis of glandular organs. Glandular stem cells are defined as the original initiating cells of these organs, allowing development and regeneration through lineage differentiation from stem and progenitor (adult stem) through intermediate cells to terminal differentiation. The prostatic stem/progenitor cell model system is presented as an example of glandular epithelial tissue turnover. In the prostatic epithelium, there are rare populations of cells that have a function that approximates to the stem and progenitor roles. These give rise to intermediate or transit-amplifying (TA) cells that can differentiate into the various mature cells of the prostatic ducts and acini, including basal cells (BC), secretory luminal cells (LC), and neuroendocrine (NE) cells with different proportions. Other glandular organs such as gastrointestinal (GI) tract and mammary glands have similar cell lineage arrangements with different differentiation potentials. Tissue recombination experiments show that exposure to inductive mesenchyme is sufficient to stimulate a stem cell population to generate daughter populations different from the tissue of origin and may be sufficient, at least in some cases, to force transdifferentiation of committed epithelial cells.