Short hairpin RNA-expressing bacteria elicit RNA interference in mammals

Nat Biotechnol. 2006 Jun;24(6):697-702. doi: 10.1038/nbt1211. Epub 2006 May 14.


RNA-interference (RNAi) is a potent mechanism, conserved from plants to humans for specific silencing of genes, which holds promise for functional genomics and gene-targeted therapies. Here we show that bacteria engineered to produce a short hairpin RNA (shRNA) targeting a mammalian gene induce trans-kingdom RNAi in vitro and in vivo. Nonpathogenic Escherichia coli were engineered to transcribe shRNAs from a plasmid containing the invasin gene Inv and the listeriolysin O gene HlyA, which encode two bacterial factors needed for successful transfer of the shRNAs into mammalian cells. Upon oral or intravenous administration, E. coli encoding shRNA against CTNNB1 (catenin beta-1) induce significant gene silencing in the intestinal epithelium and in human colon cancer xenografts in mice. These results provide an example of trans-kingdom RNAi in higher organisms and suggest the potential of bacteria-mediated RNAi for functional genomics, therapeutic target validation and development of clinically compatible RNAi-based therapies.

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Colonic Neoplasms / genetics*
  • Colonic Neoplasms / microbiology*
  • Escherichia coli / genetics*
  • Female
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Mice, Nude
  • MicroRNAs / genetics*
  • RNA Interference*
  • RNA, Bacterial / genetics*
  • RNA, Small Interfering / genetics*


  • MicroRNAs
  • RNA, Bacterial
  • RNA, Small Interfering