Telomerase activity in human intestine.
Telomerase activity in human intestine.
复制标题
人肠道中的端粒酶活性。
DOI：
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发表时间：
1996
影响因子：
5.2
通讯作者：
T. Yokoyama
中科院分区：
文献类型：
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作者：
E. Hiyama;N. Tatsumoto;T. Kodama;K. Hiyama;J. Shay;T. Yokoyama
在没有端粒酶活性的人体细胞中，由端粒重复序列TTAGGG组成的染色体末端随着每次细胞分裂而逐渐侵蚀。在生殖细胞和永生细胞中，端粒酶活性维持端粒的长度，从而弥补了“末端复制问题”。端粒进行性缩短和端粒酶活性的重新激活被认为是细胞衰老和永生化的关键机制之一。已经表明，虽然大多数体细胞不具有可检测的端粒酶活性，但几乎所有癌症都具有端粒酶活性。因此，端粒酶活性的检测可能在癌症的早期诊断中具有实用性，并且可能是治疗干预的新靶点。然而，最近有证据表明，一些细胞的更新组织，如造血细胞和基底细胞的表皮，具有可检测的端粒酶活性。在本研究中，我们报告检测端粒酶活性在正常人肠粘膜。这种活性定位于每个隐窝的下三分之一，并且可能来源于肠干细胞。由于与儿童相比，成人的肠端粒重复序列较短，因此肠中的端粒酶活性不足以维持端粒长度，但可能足以为这种更新组织提供延长的增殖能力。
In human somatic cells without the activity of telomerase, the ends of chromosomes consisting of the telomeric repeats TTAGGG progressively erode with each cell division. In germline and immortal cells telomerase activity maintains telomere length and thus compensates for the 'end-replication problem'. Progressive telomere shortening and reactivation of telomerase activity have been considered to be one of the key mechanisms in cellular senescence and immortalization. It has been shown that while most somatic cells do not have detectable telomerase activity, almost all cancers do have telomerase activity. Thus, detection of telomerase activity may have utility in the early diagnosis of cancer and may be a new target for therapeutic intervention. However, there is recent evidence that some cells of renewal tissues, such as hematopoietic cells and basal cells of the epidermis, have detectable telomerase activity. In the present study, we report detectable telomerase activity in normal human intestinal mucosa. This activity is localized to the lower third of each crypt and may be derived from intestinal stem cells. Since intestinal telomeric repeats are shorter in adults when compared to children, the telomerase activity in the intestine is insufficient to maintain telomere length but may be sufficient to provide extended proliferative capacity for such renewal tissues.