端粒、端粒酶系统的调控与研究现状

Progress on telomere and telomerase

端粒是指位于真核细胞线性染色体末端的特殊结构 ,由TTAGGG的DNA重复序列和端粒结合蛋白所构成的一种核蛋白复合体。端粒酶对端粒结构的稳定起着重要的作用 ,而端粒结构和端粒结合蛋白也影响端粒酶活性。在大多数组织端粒酶活性的抑制是在出生前由于hTERT转录水平的抑制 ,而在 90 %以上的癌细胞中通过hTERT表达上调被激活。端粒酶活性受多水平调控 ,本文从以下方面描述 :端粒酶活性和细胞分化、端粒酶活性的分子调节、端粒酶活性与细胞周期、端粒酶与肿瘤现状及端粒酶活性与其他因素 ,因此 ,可能在不同的细胞有不同的因素。

Telomere is a specific ribonucleoprotein complex composed of repeats of sequence TTAGGG, and located at the eukaryotic chromosometerminus. While it plays an important role in maintenance of telomere structural stability, telomerase is also involved in the regulation of telomerase activity. Telomerase activity is due to transcriptional repression of the catalytic subunit hTERT in most tissues prior to birth and is reactivated by upregulation of hTERT expression in over 90% of cancer cells. The mechanisms involved in telomerase regulation are still far from being fully established. Telomerase activity is subject to multiple levels of control and may be regulated by different factors in different cellular contexts. In this paper, some factors such as cell differentiation, molecular regulation, cell cycle and actuality of telomerase was reviewed.