RNA干扰 (RNA interference,RNAi)是由双链 RNA(double- stranded RNA,ds RNA)引发的转录后基因沉默机制 (posttranscriptional gene silencing,PTGS)。 ds RNA经核酸酶降解成 2 1～ 2 3nt的小片段 ,并以其为模板 ,特定位点、特定间隔降解与之序列相应的 m RNA。 RNAi是真核生物中普遍存在的抵抗病毒入侵、抑制转座子活动、调控基因表达的监控机制。目前已成功用于基因功能和信号传递系统上下游分子相互关系的研究 ,有可能为肿瘤基因治疗提供新策略 RNA interference (RNAi) is a posttranscriptional gene silencing (PTGS) triggered by double-stranded RNA (dsRNA). The dsRNA is degraded by nucleases into small fragments of 21-23 nt, and uses it as a template for site-specific and specific degradation of m RNAs corresponding to the sequences. RNAi is a ubiquitous monitoring mechanism in eukaryotes to resist virus invasion, inhibit transposon activity and regulate gene expression. Has been successfully used for gene function and signaling molecules upstream and downstream molecules of the relationship between the research, it may provide a new strategy for gene therapy of cancer