Serakinci Nedime, Cagsin Huseyin, Mavis Merdiye
Department of Medical Genetics, Faculty of Medicine, Near East University, Nicosia, Cyprus.
Department of Molecular Biology and Genetics, Faculty of Art and Sciences, Near East University, Nicosia, Cyprus.
Methods Mol Biol. 2019;2045:217-224. doi: 10.1007/7651_2018_120.
Telomeres are repetitive genetic materials that protect the chromosomes by capping the ends of chromosomes. Each time a cell divides, telomeres get shorter. Telomere length is mainly maintained by telomerase. This enzyme is present in the embryonic stem cells in high concentrations and declines with age. It is still unclear to what extend there is telomerase in adult stem cells, but considering these are the founder cells to the cells of the all tissues in a body, understanding the telomere dynamics and expression of telomerase in adult stem cells is very important.Telomere length has been implicated as one of the markers for neoplastic transformation in both in vivo and in vitro studies. During cancerogenesis, telomeres shorten due to high cell turnover and repeats are added by active telomerase or alternative lengthening of telomeres (ALT). This gradual shortening is replication driven and does not necessarily explain the presence of ultrashort telomeres. Ultrashort telomeres are observed when there is a sudden shortening in telomeres not related with cell division and may arise from breaks in telomeres due to oxidative damage and replication slippage.Universal STELA is an accurate method for evaluation of ultrashort telomeres in hMSC-telo1 cells. Compared to TRF assay, U-STELA is developed to overcome several problems in detecting abrupt telomere shortening in a single chromosome.
端粒是一种重复性遗传物质,通过封端染色体末端来保护染色体。细胞每次分裂时,端粒都会变短。端粒长度主要由端粒酶维持。这种酶在胚胎干细胞中浓度很高,并随年龄增长而下降。目前尚不清楚成体干细胞中端粒酶的存在程度,但考虑到成体干细胞是体内所有组织细胞的起始细胞,了解成体干细胞中端粒动态和端粒酶表达非常重要。在体内和体外研究中,端粒长度都被认为是肿瘤转化的标志物之一。在肿瘤发生过程中,由于细胞更新率高,端粒会缩短,而活性端粒酶或端粒替代延长(ALT)会添加重复序列。这种逐渐缩短是由复制驱动的,并不一定能解释超短端粒的存在。当端粒突然缩短且与细胞分裂无关时,会观察到超短端粒,这可能是由于氧化损伤和复制滑移导致端粒断裂引起的。通用STELA是评估hMSC-telo1细胞中超短端粒的一种准确方法。与端粒重复序列荧光原位杂交(TRF)分析相比,开发通用STELA是为了克服在检测单条染色体中端粒突然缩短时遇到的几个问题。