Abstract: Objective To explore the application of artificial microRNA in setting up gene knockdown Cell model, and compared with siRNA. Methods First of all, we constructed vectors, and prepared siRNA fragments targeting on DJ-1. Then we transcient transfected the artificial miRNA and siRNA into MN9D cells by lipofectamine2000 reagent, the mRNA and protein expression level of DJ-1 gene were detected by real-time PCR and Western blots,respectively. Results Compared with control group, DJ-1 expression level was decreased significantly in both artificial miRNA and siRNA groups. DJ-1 was knockdowned by different level. DJ-1 was decreased 90%（p<0.05）at mRNA expression level, and decreased 70%~85% (p<0.05) at protein level in MN9D cells transfected with the artificial miRNA. While DJ-1 was decreased 50%~70%（p<0.05）at mRNA expression level, and decreased 20%~50%（p<0.05）at protein level in MN9D cells transfected with siRNA. Comparing with siRNA, miRNA was more effective in silencing DJ-1. Conclusion The artificial miRNA and siRNA are both effective in silencing gene. miRNA has more significant function in knocking down DJ-1 than siRNA.

Key words: DJ-1, microRNA, siRNA, RNA interference