Li Zeng-Jun, Qiu Lu-Gui
Tianjin Institute of Hematology and Hospital for Blood Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Tianjin 300020, China.
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2008 Oct;16(5):1237-41.
The small RNAs include siRNA and miRNA. SiRNA is the splicing product of exogenous dsRNA by which to keep genome stability, while miRNA are processed from endogenous genome and work as a post-transcriptional regulator for gene expression. The small RNAs act in two ways: mediate degradation of of target RNA and inhibit translation of protein. The former requires the accurate complementation between small RNA and target RNA, while the latter requires only partial complementation. Which mechanism used depends on complementation degree, but not their origins. The RNAi as a technique for down-regulating target gene expression has been widely used in functional genomic studies and hematologic studies, especially for translocation-related fusion gene, apoptosis-related gene and MDR gene in leukemia. The results show that RNAi technique not only is the powerful tool for study mechanism but also has therapeutic potentials in clinic. Some studies reveal that changes of miRNA expression exist in many hematological malignancies and relate to known oncogenes, which indicates the miRNA is involved in pathogenesis of these diseases. This article reviews the discovery and effect of RNAi and small RNAs, as well as the similarities and differences between siRNA and miRNA, and focuses on the research of small RNAs in hematological malignancies.
小RNA包括小干扰RNA（siRNA）和微小RNA（miRNA）。siRNA是外源性双链RNA的剪接产物，用于维持基因组稳定性，而miRNA则由内源性基因组加工而成，作为基因表达的转录后调节因子发挥作用。小RNA通过两种方式发挥作用：介导靶RNA的降解和抑制蛋白质的翻译。前者需要小RNA与靶RNA之间精确互补，而后者仅需要部分互补。使用哪种机制取决于互补程度，而不是它们的来源。RNA干扰作为一种下调靶基因表达的技术，已广泛应用于功能基因组学研究和血液学研究，特别是用于白血病中与易位相关的融合基因、凋亡相关基因和多药耐药基因。结果表明，RNA干扰技术不仅是研究机制的有力工具，而且在临床上具有治疗潜力。一些研究表明，许多血液系统恶性肿瘤中存在miRNA表达变化，且与已知的癌基因有关，这表明miRNA参与了这些疾病的发病机制。本文综述了RNA干扰和小RNA的发现与作用，以及siRNA和miRNA之间的异同，并重点关注小RNA在血液系统恶性肿瘤中的研究。
