Department of Zoology, The University of Burdwan, Burdwan, West Bengal, India.
Pathol Oncol Res. 2019 Jul;25(3):1263-1265. doi: 10.1007/s12253-018-0425-5. Epub 2018 Jun 8.
Telomeres, the specific DNA-protein structures remains at both ends of each chromosome and are crucial in the maintenance of chromosome integrity and genomic stability with protection of the chromosome from damage and degradation.. Increasing evidences suggest the correlation between telomere length and the development of cancers, but the findings remain obscure. Generally, the average length of telomere repeats at the ends of chromosomes that gives a clue in providing indirect information about their mitotic history. It plays immense role in preventing genome from nucleolytic degradation, unnecessary recombination, repair, and interchromosomal fusion. It has major role in storing the information in the genome. Telomere attrition during successive cell divisions induces chromosomal instability and contributes significantly to genomic rearrangements that can result in tumorigenesis. Convincing evidence documented that a meagre portion of telomeric DNA is expelled out during mitotic stage of cell division. But accelerated shortening telomere length at critical level triggers senescence and/or apoptosis. Various harmful agents with bad lifestyles are responsible in inducing shortening of telomere length with damage of DNA resulting to occurrence of disease with shortening of lifespan. Besides, telomerases, the specialized polymerase that synthesizes new telomere repeats and is strongly associated with cancer facilitating malignant transformation. Therefore, in the study, it is highlighted that the telomeres may play diverse roles in different cancers whereas shortening of telomere length may be risk factors for the development of tumors.
端粒是位于每条染色体两端的特定 DNA-蛋白质结构,对于维持染色体的完整性和基因组的稳定性至关重要,它可以保护染色体免受损伤和降解。越来越多的证据表明端粒长度与癌症的发展有关,但这些发现仍不清楚。一般来说,染色体末端端粒重复序列的平均长度提供了关于它们有丝分裂历史的间接信息。它在防止基因组的核酶降解、不必要的重组、修复和染色体间融合方面发挥着巨大的作用。它在存储基因组信息方面也起着重要作用。在连续的细胞分裂中端粒的损耗会导致染色体不稳定,并显著促进基因组重排,从而导致肿瘤的发生。有令人信服的证据表明,在有丝分裂阶段的细胞分裂过程中,端粒 DNA 的一小部分被排出。但是,端粒长度在关键水平上的加速缩短会引发衰老和/或细胞凋亡。各种有害的因素和不良的生活方式会导致端粒长度的缩短,从而导致 DNA 损伤,引发疾病,缩短寿命。此外,端粒酶是一种专门合成新端粒重复序列的聚合酶,与癌症密切相关,促进恶性转化。因此,在研究中强调,端粒可能在不同的癌症中发挥不同的作用,而端粒长度的缩短可能是肿瘤发展的危险因素。