中文摘要：

肿瘤是导致人类死亡的主要原因之一，找到具有早期诊断意义的肿瘤标志对恶性肿瘤治疗至关重要。微小RNA（MicroRNAs，miRNAs）作为致癌或抑癌基因，参与细胞增殖、分化、凋亡以及各种免疫反应，其可以稳定地存在于血清和血浆等多种体液中，其特定的表达谱与多种肿瘤的发生密切相关，因此有望成为肿瘤诊断、分型、疗效监测以及预后判断的生物标志物。在此，对循环miRNAs来源、检测方法以及在各种肿瘤中的临床应用综述如下。

英文摘要：

Cancer is one of the leading cause of death in the world. Development of minimally invasive biomarkers for early detection of cancer is urgently needed to reduce the morbidity and mortality. MiRNAs may act as oncogenes or tumour-suppressors, participating in a series of biological activities including cell proliferation, differentiation, apoptosis and immune response. Recent studies have indicated that miRNAs take a stable, reproducible, cell-flee form in the body fluid, and their unique expression patterns are correlated with certain human diseases, including various types of cancer. Circulating miRNAs enjoys the potential as blood-based fingerprints for cancer diagnosis, classification, therapeutic decisions, and prognosis. This article focuses on the origin, detecting method of circulating miRNAs and their potential as minimally invasive biomarkers for tumor malignancy.