title: Multispecies-compatible antitumor effects of a cross-species small-interfering RNA against mammalian target of rapamycin.
abstract: Successful development of sequence-specific siRNA (small interfering RNA)-based drugs requires an siRNA design that functions consistently in different organisms. Utilizing the CAPSID program previously developed by our group, we here designed siRNAs against mammalian target of rapamycin (mTOR) that are entirely complementary among various species and investigated their multispecies-compatible gene-silencing properties. The mTOR siRNAs markedly reduced mTOR expression at both the mRNA and protein levels in human, mouse, and monkey cell lines. The reduction in mTOR expression resulted in inactivation of both mTOR complex I and II signaling pathways, as confirmed by reduced phosphorylation of p70S6K (70-kDa ribosomal protein S6 kinase), 4EBP1 (eIF4E-binding protein 1), and AKT, and nuclear accumulation of FOXO1 (forkhead box O1), with consequent cell-cycle arrest, proliferation inhibition, and autophagy activation. Moreover, interfering with mTOR activity in vivo using mTOR small-hairpin RNA-expressing recombinant adeno-associated virus led to significant antitumor effects in xenograft and allograft models. Thus, the present study demonstrates that cross-species siRNA successfully silences its target and readily produces multispecies-compatible phenotypic alterations-antitumor effects in the case of mTOR siRNA. Application of cross-species siRNA should greatly facilitate the development of siRNA-based therapeutic agents.
authors.affiliation: Department of Microbiology, University of Ulsan College of Medicine, 86 Asanbyeongwon-Gil Songpa-Gu, Seoul, Korea.
authors.forename: Jeonghyun
authors.initials: J
authors.lastname: Ahn
authors.forename: Ha-Na
authors.initials: HN
authors.lastname: Woo
authors.forename: Ara
authors.initials: A
authors.lastname: Ko
authors.forename: Maria
authors.initials: M
authors.lastname: Khim
authors.forename: Catherine
authors.initials: C
authors.lastname: Kim
authors.forename: Nung Hwa
authors.initials: NH
authors.lastname: Park
authors.forename: Ho-Young
authors.initials: HY
authors.lastname: Song
authors.forename: Seong Who
authors.initials: SW
authors.lastname: Kim
authors.forename: Heuiran
authors.initials: H
authors.lastname: Lee
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001483:Base Sequence; D002460:Cell Line; D000229:Dependovirus / Q000235:genetics; D015195:Drug Design; D004354:Drug Screening Assays, Antitumor; D005786:Gene Expression Regulation / Q000187:drug effects; D020868:Gene Silencing; D000882:Haplorhini; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010766:Phosphorylation; D034741:RNA, Small Interfering / Q000494:pharmacology*; D015398:Signal Transduction / Q000235:genetics; D058570:TOR Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D034741:RNA, Small Interfering; C546842:MTOR protein, human; C546843:mTOR protein, mouse; D058570:TOR Serine-Threonine Kinases