ABSTRACT
Objective To construct five shRNA-expression plasmids and to investigate the expression of Smad2 in TGF-?/ Smads signal transduction treated with shRNA-expression plasmid.Methods Five shRNA-Smad2 DNA sequences from mRNA sequence of mouse Smad2 gene were designed and synthesized.DNA oligonucleotides encoding an appropriate shRNA were inserted to shRNA expression vector respectively.Five shRNA-Smad2 expression plasmids were obtained and then transfected into NIH/3T3 cells.The suppressed expression of Smad2 was assessed by RT-PCR and Western-blotting.Results The shRNA-expression plasmid numbered 2.4 could markedly reduce the expression of Smad2.The suppression effect of the RNAi-pool composed of four different plasmids was more obvious than that of any single.Conclusion The shRNA-expression plasmids were successfully constructed,which could specifically and effectively suppress the expression of Smad2.The method of using a mixture of RNAi plasmids to improve the RNAi efficiency was established.