ABSTRACT
Living cells are challenged by DNA damage of exogenous and endogenous origin, which threaten cell survival and cell function if not repaired efficiently and accurately. Double-strand breaks (DSBs) are among the most fatal DNA lesions a cell can incur. DNA damage is especially dangerous for adult stem cells (ASCs), which are responsible for tissue homeostasis and regeneration in the adult. This chapter discusses the response to DNA damage of ASCs compared to engaged or more differentiated cells, including the possible implication of this process in tissue regeneration, ageing, and cancer development. Non-homologous end-joining is the prevalent DSB repair pathway in mammalian cells. It takes place during the entire cell cycle, and consists in the joining of two DNA ends with minor or no modifications at the junction site, largely depending on the nature of the DNA ends.
