Long-term RNA interference from optimized siRNA expression constructs in adult mice.
DNA constructs for small interfering RNA (siRNA) expression in mammalian cells have the potential for longer-term target gene knockdown than synthetic siRNAs. We compared in adult mice the efficacy and longevity of target gene knockdown from siRNA expression cassettes contained in plasmids, PCR-generated linear constructs or PCR constructs containing "dumbbell" ends using the hydrodynamic delivery method. Plasmid siRNA expression constructs were more effective than PCR constructs for target gene knockdown. The efficacy of the PCR constructs was improved by addition of short extensions beyond the transcription termination signal and greatly improved by addition of dumbbell ends. Constructs containing the H1 promoter were significantly less effective in mice than those containing the U6 promoter, whereas both promoters functioned equally well in cultured cells. Target gene knockdown perdured for at least 20 weeks in mice after delivery of either PCR or plasmid siRNA expression cassettes. These results will help guide RNAi vector design.
Mirus Bio Corporation, 505 S. Rosa Road, Madison, WI 53719, USA.
Christine I
CI
Wooddell
Cristopher V
CV
Van Hout
Thomas
T
Reppen
David L
DL
Lewis
Hans
H
Herweijer
D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D020868:Gene Silencing; D018390:Gene Targeting / Q000379:methods*; D017930:Genes, Reporter / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D016133:Polymerase Chain Reaction / Q000379:methods*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000235:genetics*; D013997:Time Factors; D014162:Transfection / Q000379:methods*
D034741:RNA, Small Interfering