Cell competition and its perspective on oral science

Abstract

Like Darwin’s theory of the struggle for existence, cells in a tissue compete among each other for survival, and the cells with higher fitness overcome those with lower fitness, which is called “cell competition”. In cell competition, winner cells proliferate and loser cells die mainly through apoptosis. Morata and Ripoll (1975) reported that Drosophila cells with heterozygotes of a mutated gene of Minutes, a ribosomal protein, Minutes ＋/－, were excluded by cell death in a culture with normal cells, Minutes －/－, in which cell competition was thought to occur between Minutes ＋/－ and normal cells. In cell competition, several molecules have been found to discriminate between winners and losers. For example, the cells expressing higher level of myc strongly exclude the neighboring cells; the strong winner is called a “super-competitor”. Many studies have revealed that winner cells transmit signals to loser cells through soluble factors or cell-cell contact, leading the loser cells to cell death. Cell competition is associated with tumorigenesis as well as tumor suppression. Atypical mutated cells occurring in a tissue may be excluded by normal cells through cell competition. On the other hand, atypical cells, which acquire higher ability to grow, dominate in tissue by overcoming normal cells, which may be involved in “field cancerization”. Reviewing these articles, cell competition is expected to play a role in the pathology of some oral diseases.