The activation, survival, and quiescence of stem cells (SCs) are dependent
on signaling within their niche or microenvironment. There are many types of SCs and
SC niches that can be found in the human body. A single organ may contain more than
one niche to accommodate for both slow and fast cycling SC populations. It appears
that many SC niches possess similarities in both their cellular and molecular
components. This chapter focuses on cellular organization, key molecular regulators,
and the role of SC niches in aging and cancer.
Keywords: Autocrine, apoptosis, blood, canonical, extrinsic factors, growth
factors, hair follicle, hematopoietic, intrinsic factors, intestine, lineage,
microenvironment, mesenchymal, mechanism, neuron, paracrine, quiescence,
regulation, stem cell niche, stromal, transduction.
