中文摘要：

微小RNA（microRNA,miRNA）是一种长度为21～25个核苷酸组成的内源性非编码小分子RNA,可以通过与靶基因序列特异性翻译抑制的相互作用在转录水平对基因表达进行调节,从而参与多种重要的生物学进程。miRNA在人体肿瘤的发生和发展过程中发挥非常重要的作用,已发现若干miRNA与某些肿瘤的发生和发展有着密切的关系。不仅是组织中的miRNA,外周血循环中的miRNA也与肿瘤的发生和发展密切相关,部分可作为疾病的诊断标志物,为临床疾病的早期诊断提供了新思路。血中肿瘤特异性miRNA的检出对肿瘤的早期诊断具有至关重要的作用。

英文摘要：

MicroRNAs（miRNAs）are a group of endogenous non-coding small RNA molecules of 21-25nt.They can regulate gene expression at the transcriptional level through interaction with inhibition of target gene translation,participating in a variety of important biological processes.Increasing studies have found that miRNA plays a very important role in the development and progression of tumor,and that several miRNAs are closely related to the development of some tumors.Not only the miRNAs in the tissue,but also those in the peripheral blood are involved in the tumorigenesis,and they may be taken as biomarkers for diagnosis of patients,casting new lights on the early diagnosis in clinical practice.Detection of tumor-specific miRNAs in the blood is of great importance for the early diagnosis of tumors.