ABSTRACT
In this chapter, the authors illustrate how adult stem cells can become functionally compromised with age and discuss how such changes relate to current theories on the mechanisms of aging. They then consider how stem cells or the acquisition of stem cell properties can explain the origins and development of cancer and how knowledge of this is changing the prospects for the discovery of novel therapies. By performing combinations of transplantations between young or old donors into young or old recipients (“heterochronic” transplantations), it is possible to gain some insight into the effects of aging on the stem cell and its niche. The fact that stem cells underpin tissue homeostasis means that the combined effects of chronological and replicative aging inevitably lead to defects in tissue repair and ultimately to tissue atrophy. Aging involves a complex interplay of the effects of cumulative damage, altering stem cell function at several molecular levels.
