Role of α7-Nicotinic Acetylcholine Receptor in Normal and Cancer Stem Cells

The alpha 7-nicotinic acetylcholine receptor (alpha 7-nAChR) is widely known as a neurotransmitter receptor in nervous systems. alpha 7-nAChR is also present in a variety of non-neuronal tissues, where it has been implicated in the regulation of essential cellular functions including proliferation, survival, differentiation and communication. We have recently found in breast cancer that alpha 7-nAChR is involved in the proliferation of cancer stem cells, which constitute a minor subpopulation responsible for tumor development and metastasis. Since growing evidence suggests that alpha 7-nAChR is present not only in mature tissues and organs but also in undifferentiated stem cells and progenitor cells, alpha 7-nAChR emerges as a key mediator in the regulation of self-renewal and differentiation. We provide here an overview of the recent works on the expression and function of alpha 7-nAChR in normal and cancer stem cells, and their relevance to disease-related cellular dysfunction. Understanding the role of alpha 7-nAChR in stem cells would be of great interest for its application potential in drug discovery and in regenerative medicine.