Rationally designed siRNAs without miRNA-like off-target repression

Heeyoung Seok, Eun Sook Jang, Sung Wook Chi

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Small interfering RNAs (siRNAs) have been developed to intentionally repress a specific gene expression by directing RNA-induced silencing complex (RISC), mimicking the endogenous gene silencer, microRNAs (miRNAs). Although siRNA is designed to be perfectly complementary to an intended target mRNA, it also suppresses hundreds of off-targets by the way that miRNAs recognize targets. Until now, there is no efficient way to avoid such off-target repression, although the mode of miRNA-like interaction has been proposed. Rationally based on the model called "transitional nucleation" which pre-requires base-pairs from position 2 to the pivot (position 6) with targets, we developed a simple chemical modification which completely eliminates miRNA-like off-target repression (0%), achieved by substituting a nucleotide in pivot with abasic spacers (dSpacer or C3 spacer), which potentially destabilize the transitional nucleation. Furthermore, by alleviating steric hindrance in the complex with Argonaute (Ago), abasic pivot substitution also preserves near-perfect on-target activity (~80-100%). Abasic pivot substitution offers a general means of harnessing target specificity of siRNAs to experimental and clinical applications where misleading and deleterious phenotypes from off-target repression must be considered.

Original languageEnglish
Pages (from-to)135-136
Number of pages2
JournalBMB reports
Issue number3
Publication statusPublished - 2016 Mar 1

Bibliographical note

Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. NRF-2015R1A2A1A13001834).

Publisher Copyright:
© 2016 by the The Korean Society for Biochemistry and Molecular Biology.


  • Abasic pivot substitution
  • Ago
  • Off-target effect
  • Spacer
  • miRNA
  • siRNA

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology


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