Asymmetric RNA Duplexes Suppress Bcl-2 Gene Expression By RNA Interference In HeLaB2 Cells

RNA interference (RNAi) has been one of the hot fields in biological and drug researches. Current RNAi approaches in mammalian cells and clinical trial rely on small interfering RNA (siRNA) of symmetrical duplexes. Most of the general structure of siRNA is two complementary strands of 19-23 bp in length with 2-nt overhangs at both 3'-ends. Although there have been 15 kinds of the siRNA-based drugs which have entered clinical research, there are many challenges to overcome for siRNA-based drug gene therapy. Aasymmetric small interfering RNA (asiRNA) was proposed in Nature Biotechnology by Sun until December 2008. The asymmetric siRNA improved by chemical modification has many advantages, such as good stability, high cellular affinity and less off-target effects. Thus it has a wide field of application with good prospects.We designed and synthesized a series asiRNAs for targeting bcl-2 gene.The real time PCR(RT-PCR) assay was measured, cytotoxicity, cell proliferation assay, flow cytometric assay and miRNA microarray were performed. The results showed that asiRNAs could cause gene silencing more efficaciously, thereby restrained the growth of the tumour cells, and induced some microRNAs expression differentially, which have up or down regulated in certain tumor cells.