title: U1 adaptors result in reduction of multiple pre-mRNA species principally by sequestering U1snRNP.
abstract: U1 Adaptors are a recently reported novel approach for targeted reduction of mRNA transcripts. A U1 adaptor oligonucleotide comprising of a target-complimentary hybridization domain and a U1 recruitment domain, directs the U1 snRNP complex to the terminal exon of a targeted gene, subsequently inhibiting poly(A) tail addition and leading to degradation of that RNA species within the nucleus. Here, we present data demonstrating U1 adapter-mediated gene silencing can result in significant 'off-target' silencing effects as demonstrated by the reduction of multiple mRNA species that were not intended to be targeted. Our data suggest that a substantial portion of this U1 adaptor-mediated off-target mRNA reduction is the result of sequestration U1 snRNP at levels sufficient to affect splicing and processing of non-target transcripts.
authors.affiliation: Department of Core Antisense Research, ISIS Pharmaceuticals, Inc, 1896 Rutherford Road, Carlsbad, CA 92008, USA. tvickers@isisph.com
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Vickers
authors.forename: Mahyar
authors.initials: M
authors.lastname: Sabripour
authors.forename: Stanley T
authors.initials: ST
authors.lastname: Crooke
mesh_terms: D015536:Down-Regulation; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D009841:Oligonucleotides; D016376:Oligonucleotides, Antisense; D012322:RNA Precursors / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism*; D012342:RNA, Small Nuclear / Q000037:antagonists & inhibitors; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000037:antagonists & inhibitors*
chemical_list: D009841:Oligonucleotides; D016376:Oligonucleotides, Antisense; D012322:RNA Precursors; D012333:RNA, Messenger; D012342:RNA, Small Nuclear; D017412:Ribonucleoprotein, U1 Small Nuclear; C405483:U1 small nuclear RNA