Use of guanidinopropyl-modified siRNAs to silence gene expression

Abstract

Silencing gene expression by harnessing the RNA interference (RNAi) pathway with short interfering RNAs (siRNAs) has useful analytical and potentially therapeutic application. To augment silencing effi cacy of siRNAs, chemical modifi cation has been employed to improve stability, target specifi city, and delivery to target tissues. siRNAs incorporating guanidinopropyl (GP) moieties have demonstrated enhanced target gene silencing in cell culture and in vivo models of hepatitis B virus replication. Here we describe the synthesis of GP-modifi ed siRNAs and use of 5′ rapid amplifi cation of cDNA ends (5′ RACE) to verify an RNAi-mediated mechanism of action of these novel chemically modifi ed siRNAs.