title: Antisense Oligonucleotides Modulating Activation of a Nonsense-Mediated RNA Decay Switch Exon in the ATM Gene.
abstract: ATM (ataxia-telangiectasia, mutated) is an important cancer susceptibility gene that encodes a key apical kinase in the DNA damage response pathway. ATM mutations in the germ line result in ataxia-telangiectasia (A-T), a rare genetic syndrome associated with hypersensitivity to double-strand DNA breaks and predisposition to lymphoid malignancies. ATM expression is limited by a tightly regulated nonsense-mediated RNA decay (NMD) switch exon (termed NSE) located in intron 28. In this study, we identify antisense oligonucleotides that modulate NSE inclusion in mature transcripts by systematically targeting the entire 3.1-kb-long intron. Their identification was assisted by a segmental deletion analysis of transposed elements, revealing NSE repression upon removal of a distant antisense Alu and NSE activation upon elimination of a long terminal repeat transposon MER51A. Efficient NSE repression was achieved by delivering optimized splice-switching oligonucleotides to embryonic and lymphoblastoid cells using chitosan-based nanoparticles. Together, these results provide a basis for possible sequence-specific radiosensitization of cancer cells, highlight the power of intronic antisense oligonucleotides to modify gene expression, and demonstrate transposon-mediated regulation of NSEs.
authors.affiliation: 1 Faculty of Medicine, University of Southampton , Southampton, United Kingdom .
authors.forename: Jana
authors.initials: J
authors.lastname: Kralovicova
authors.affiliation: 2 Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto , Porto, Portugal .|3 Instituto de Engenharia Biomédica (INEB), Universidade do Porto , Porto, Portugal .
authors.forename: Pedro M D
authors.initials: PM
authors.lastname: Moreno
authors.affiliation: 1 Faculty of Medicine, University of Southampton , Southampton, United Kingdom .|4 Wessex Regional Genetics Laboratory, Salisbury Hospital , Salisbury, United Kingdom .
authors.forename: Nicholas C P
authors.initials: NC
authors.lastname: Cross
authors.affiliation: 2 Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto , Porto, Portugal .|3 Instituto de Engenharia Biomédica (INEB), Universidade do Porto , Porto, Portugal .|5 Faculdade de Engenharia and Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto , Porto, Portugal .
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Pêgo
authors.affiliation: 1 Faculty of Medicine, University of Southampton , Southampton, United Kingdom .
authors.forename: Igor
authors.initials: I
authors.lastname: Vorechovsky
mesh_terms: D020087:Alu Elements; D064007:Ataxia Telangiectasia Mutated Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002461:Cell Line, Transformed; D048271:Chitosan / Q000737:chemistry; D004251:DNA Transposable Elements; D005091:Exons; D015870:Gene Expression; D005822:Genetic Vectors / Q000737:chemistry / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D007438:Introns; D008214:Lymphocytes; D009154:Mutation; D053758:Nanoparticles / Q000737:chemistry / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000138:chemical synthesis / Q000235:genetics* / Q000378:metabolism; D059367:RNA Cleavage; D012326:RNA Splicing; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism
chemical_list: D004251:DNA Transposable Elements; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D048271:Chitosan; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins
keywords: ATM; alternative splicing; antisense oligonucleotides; lymphoid cancer; nanoparticles; nonsense-mediated RNA decay; transposon