apoptosis

apoptosis [(ap-uhp-toh-sis)]

The programmed death of a cell. Scientists believe that this process is governed by chemical signals a given cell receives from its neighbors.

Note: It is thought some forms of cancer may result when this process of cell death is somehow interrupted, allowing cells to grow unchecked, with the result being a cancerous tumor.

Main Entry: apop·to·sis
Pronunciation: "ap-&(p)-'tO-sis, -äp-, -O-; "A-päp-
Function: noun
: a genetically determined process ofcell self-destruction that is marked by the fragmentation of nuclear DNA, is activated either by the presence of a stimulus or by the removal of a stimulus or suppressing agent, is a normalphysiological process eliminating DNA-damaged, superfluous, or unwanted cells (as immune cells targeted against the self in the development of self-tolerance or larval cells in amphibians undergoingmetamorphosis), and when halted (as by genetic mutation) may result in uncontrolled cell growth and tumor formationcalled also programmed cell death —apop·tot·ic /-'tät-ik/ adjective