Popli Deepika Bablani, Sircar Keya, Chowdhry Aman
Department of Oral Pathology and Microbiology, Faculty of Dentistry, JMI, New Delhi, India.
Indian J Dent Res. 2017 Sep-Oct;28(5):574-584. doi: 10.4103/ijdr.IJDR_690_16.
The distinguishing feature of cancer cells is their ability to proliferate indefinitely, which is in contrast to the restricted cell multiplication potential for somatic cells. A better understanding of this contrasting behavior was provided in the early 1990s with the discovery of a relationship between telomeres, telomerase, aging, and cancer. Telomeres (tandem repeat DNA sequence TTAGGG) are protective caps at the ends of human chromosomes. Normal human cells experience telomere shortening with each successive cell division. However, in tumor cells, an overexpression of telomerase confers limitless replicative potential to tumor cells by continuous elongation of telomeres. The objective of this review was to systematically assess the data available on telomerase expression in oral cancer, with special reference to its role in diagnosis, prognosis, and treatment.
A systematic review of studies that investigated the telomerase expression in oral squamous cell carcinoma (OSCC) was registered with PROSPERO. Subsequent to registration, a predetermined search strategy in accordance with PRISMA guidelines was formulated, and a literature search was conducted using online databases along with hand searching.
Eighty-nine articles from PubMed, 83 from Scopus, 5 from BioMed Central, 43 from Google Scholar, and 2 from hand search were identified. A total of 21 articles were shortlisted that met strict inclusion and exclusion criteria and quality assessment. Each study was evaluated for the markers under study, type of sample used, study design/methodology, and statistical analysis. The studies were then grouped into three subheads depending on their implications in the diagnosis, prognosis, and treatment of OSCC.
This review explains the basic biology and the clinical implications of telomerase-based diagnosis and prognosis, the prospects for its use in anticancer therapy, in the context of oral cancer.
癌细胞的显著特征是其无限增殖的能力，这与体细胞有限的细胞增殖潜能形成对比。20世纪90年代初，随着端粒、端粒酶、衰老与癌症之间关系的发现，人们对这种对比行为有了更好的理解。端粒（串联重复DNA序列TTAGGG）是人类染色体末端的保护帽。正常人类细胞每次连续细胞分裂都会经历端粒缩短。然而，在肿瘤细胞中，端粒酶的过度表达通过端粒的持续延长赋予肿瘤细胞无限的复制潜能。本综述的目的是系统评估口腔癌中端粒酶表达的现有数据，特别提及其在诊断、预后和治疗中的作用。
一项对研究口腔鳞状细胞癌（OSCC）中端粒酶表达的研究的系统综述已在PROSPERO注册。注册后，根据PRISMA指南制定了预定的搜索策略，并使用在线数据库以及手工检索进行文献搜索。
从PubMed中识别出89篇文章，从Scopus中识别出83篇，从BioMed Central中识别出5篇，从谷歌学术中识别出43篇，从手工检索中识别出2篇。共有21篇文章入围，这些文章符合严格的纳入和排除标准以及质量评估。对每项研究的研究标志物、所用样本类型、研究设计/方法和统计分析进行了评估。然后根据这些研究对OSCC诊断、预后和治疗的影响将其分为三个小标题。
本综述解释了基于端粒酶的诊断和预后的基本生物学和临床意义，以及其在口腔癌背景下用于抗癌治疗的前景。
