Metcalfe A, Streuli C
School of Biological Sciences, University of Manchester, UK.
Bioessays. 1997 Aug;19(8):711-20. doi: 10.1002/bies.950190812.
Apoptosis is an essential part of the normal cellular phenotype repertoire. In the absence of appropriate survival factors, apoptosis is activated through specific signalling cassettes. Epithelia form distinctive three-dimensional cohesive structures that depend on adhesive interactions in order for these tissues to carry out their specialised roles, such as secretion and reproduction. The cellular programme that triggers apoptosis in epithelial cells has not yet been shown to differ form that in other cell types, yet the unique characteristics of epithelia endow them with specific determinants for survival. In particular, cell-matrix and cell-cell interactions are required to prevent entry of epithelial cells into apoptosis, and soluble factors that have profound effects on epithelia, such as steroid hormones or hepatocyte growth factor, also influence their survival. The regenerative capacity of certain epithelia is controlled by intrinsic expression of survival genes within stem cell populations, and may regulate the susceptibility of different epithelial tissues to undergo carcinogenesis.
细胞凋亡是正常细胞表型库的重要组成部分。在缺乏适当生存因子的情况下，细胞凋亡通过特定的信号转导途径被激活。上皮细胞形成独特的三维紧密结构，这些组织依赖于黏附相互作用来发挥其特殊功能，如分泌和繁殖。触发上皮细胞凋亡的细胞程序尚未显示出与其他细胞类型有差异，但上皮细胞的独特特征赋予了它们特定的生存决定因素。特别是，细胞与基质以及细胞与细胞之间的相互作用对于防止上皮细胞进入凋亡是必需的，而对上皮细胞有深远影响的可溶性因子，如类固醇激素或肝细胞生长因子，也会影响它们的生存。某些上皮细胞的再生能力受干细胞群体中生存基因的内在表达控制，并且可能调节不同上皮组织发生癌变的易感性。
