Radiation-Induced Aging and Genetic Instability of Mesenchymal Stem Cells: An Issue for Late Health Effects?

Adult stem cells (ASC) are extensively studied for their role as a cellular reservoir that contributes to life-long tissue regeneration, cellular renewal, recovery after trauma and prevention of degenerative diseases. Their unique capacity for long-term self-renewal and generation of committed precursor cells relies on cellular mechanisms that protect ASCs from genomic instability caused by endogenous factors and exogenous noxae. In this review it will be argued that chronic exposure of adult stem cells, in particular mesenchymal stem cells (MSC) to low-dose rate ionizing radiation could have an impact on the development of age-related degenerative diseases and/or cancer. This could be an important issue also to be considered when patient-derived MSCs are expanded ex vivo and re-implanted into target tissues for the purpose of a regenerative cell therapy.