In 1998, Fire used an exogenous dsRNA to induce the silencing of the homologous mRNA of Caenorhabditis elegans and called this process RNA interference. RNA interference refers to a process in which foreign or endogenous double-stranded RNAs specifically induce transcriptional gene silencing of homologous genes. Its mechanism is divided into four, (1) Exogenous or endogenous dsRNA is recognized by the body and cleaved by Dicer enzyme into siRNA; (2) The cleaved siRNA was amplified by RDRs enzyme and other replication-related enzymes to form a large number of siRNAs; (3) A large number of siRNAs are combined with RISC to degrade homologous mRNA; (4) siRNA spread to the body caused gene silencing.

The rapid development of RNAi technology has allowed it to occupy an important position in many research areas, Such as exploration of gene function, gene therapy, viral diseases, hereditary diseases and treatment of cancer and so on. Tumors are the result of multiple genes that interact with the gene network. Traditional technique-induced blocking of monocytic genes can’t completely inhibit or reverse tumor growth. But RNAi can use this feaure that multiple genes of the same gene family have a homology to design dsRNA molecules for this sequence. Injection of only one dsRNA can remove multiple genes. It is also possible to simultaneously inject multiple dsRNAs and to knock out multiple sequences of unrelated genes. There are a lot of RNA interference for different genes in vivo and in vitro effective inhibition of tumor cell growth, these target genes include: B c l-2, survivin, EGFR, VEGF and so on. RNA interference instead of the traditional antisense oligonucleotides for post-transcriptional gene silencing, can efficiently inhibit the target gene. Compared with the traditional method, RNA interference technology design is much simpler, the effect is rapid, the effect is obvious, its technical advantage lies in according to different diseases to design individual treatment programs.