中文摘要：

肿瘤的发生发展为复杂的多基因事件，microRNAs（miRNAs）参与其中并发挥重要作用。miR—NAs是由长度为18—25个核苷酸组成的的非编码单链小RNA分子，通过与特定的靶mRNA结合来抑制靶基因转录或蛋白翻译从而沉默靶基因的表达，作为抑癌或致癌因子与靶基因共同作用参与肿瘤发生、发展。本文从miR-519的生成与组织分布、靶基因及相关肿瘤作用机制等方面进行综述。

英文摘要：

The tumorigenesis of cancer is a complex process which involved oncogenes and anti - oncogenes. Re- cently studies had proved that miRNAs played an important role in this course, miRNAs are 18 -25nt no - coding sin- gle -stranded RNA molecules. They regulate the expression of genes by inhibiting the translating process of target mRNA through combining the specific target mRNA. miRNAs are closely related to the oncurrence and development of cancer. We review the research progress （ maturing process tissue expression, target gent and related tumor mecha- nism） of miR- 519 in different cancers.