title: Short hairpin RNA-expressing bacteria elicit RNA interference in mammals.
abstract: 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.
authors.affiliation: Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave., Boston, Massachusetts 02215, USA.
authors.forename: Shuanglin
authors.initials: S
authors.lastname: Xiang
authors.forename: Johannes
authors.initials: J
authors.lastname: Fruehauf
authors.forename: Chiang J
authors.initials: CJ
authors.lastname: Li
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics* / Q000382:microbiology*; D004926:Escherichia coli / Q000235:genetics*; D005260:Female; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics*; D034622:RNA Interference; D012329:RNA, Bacterial / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics*
chemical_list: D035683:MicroRNAs; D012329:RNA, Bacterial; D034741:RNA, Small Interfering