Apoptosis: Programmed Cell Death

Abstract

Apoptosis, or programmed cell death, is a mechanism by which cells die in order to control cell proliferation or respond to cell damage. Apoptosis can be defined as a carefully regulated process with specific morphological and biochemical features: cytoskeletal disruption, cell shrinkage, loss of contact with adjacent cells, plasma membrane blebbing, chromatin condensation, internucleosomal DNA fragmentation, and formation of apoptotic bodies. Numerous pathways and proteins control apoptosis, including the caspase activation cascade and anti-apoptotic and pro-apoptotic proteins. Apoptotic processes are involved in immune system development, differentiation, proliferation, homoeostasis, regulation, and function and removal of defective cells. Thus, dysfunction or deregulation of apoptosis is involved in a variety of diseases, including cancer. Understanding apoptosis provides the basis for novel targeted therapies that can induce death in cancer cells or sensitize them to cytotoxic agents and radiation therapy.