ABSTRACT
Cellular senescence and apoptotic cell death refer to two processes that occur throughout the life span of complex organisms such as mammals. Both processes have been conserved throughout metazoan evolution, and they most likely evolved to facilitate embryogenesis. In complex organisms, both processes are also important for preventing the development of cancer. Cellular senescence and apoptosis arrest the growth or eliminate, respectively, damaged, dysfunctional, or unneeded cells. Thus, during embryonic development and early in the life span, these processes help maintain the integrity and function of tissues. Later in life, however, both processes may contribute to phenotypes and pathologies that are associated with aging. This chapter will describe the characteristics and causes of cellular senescence and cell death. It will then discuss the role that both processes play in suppressing
tumorigenesis, and the potential roles these processes may play in contributing to aging.
