- PASSENGER-STRAND (1) (remove) - A large-scale chemical
modification screen identifies design rules to generate siRNAs
with high activity, high stability and low toxicity (2009) - The
use of chemically synthesized short interfering RNAs (siRNAs) is
currently the method of choice to manipulate gene expression in
mammalian cell culture, yet improvements of siRNA design is
expectably required for successful application in vivo. Several
studies have aimed at improving siRNA performance through the
introduction of chemical modifications but a direct comparison
of these results is difficult. We have directly compared the
effect of 21 types of chemical modifications on siRNA activity
and toxicity in a total of 2160 siRNA duplexes. We demonstrate
that siRNA activity is primarily enhanced by favouring the
incorporation of the intended antisense strand during RNA-
induced silencing complex (RISC) loading by modulation of siRNA
thermodynamic asymmetry and engineering of siRNA 3-overhangs.
Collectively, our results provi