Identification of small molecule and genetic modulators of AON-induced dystrophin exon skipping by high-throughput screening.
One therapeutic approach to Duchenne Muscular Dystrophy (DMD) recently entering clinical trials aims to convert DMD phenotypes to that of a milder disease variant, Becker Muscular Dystrophy (BMD), by employing antisense oligonucleotides (AONs) targeting splice sites, to induce exon skipping and restore partial dystrophin function. In order to search for small molecule and genetic modulators of AON-dependent and independent exon skipping, we screened approximately 10,000 known small molecule drugs, >17,000 cDNA clones, and >2,000 kinase- targeted siRNAs against a 5.6 kb luciferase minigene construct, encompassing exon 71 to exon 73 of human dystrophin. As a result, we identified several enhancers of exon skipping, acting on both the reporter construct as well as endogenous dystrophin in mdx cells. Multiple mechanisms of action were identified, including histone deacetylase inhibition, tubulin modulation and pre-mRNA processing. Among others, the nucleolar protein NOL8 and staufen RNA binding protein homolog 2 (Stau2) were found to induce endogenous exon skipping in mdx cells in an AON-dependent fashion. An unexpected but recurrent theme observed in our screening efforts was the apparent link between the inhibition of cell cycle progression and the induction of exon skipping.
O'Leary
Debra A
DA
Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America. oleary.debra@gmail.com
Sharif
Orzala
O
Anderson
Paul
P
Tu
Buu
B
Welch
Genevieve
G
Zhou
Yingyao
Y
Caldwell
Jeremy S
JS
Engels
Ingo H
IH
Brinker
Achim
A
D017398:Alternative Splicing / Q000187:drug effects; D000818:Animals; D002453:Cell Cycle / Q000187:drug effects; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics; D016189:Dystrophin / Q000235:genetics*; D004742:Enhancer Elements, Genetic / Q000235:genetics; D057075:Enzyme Assays; D005091:Exons / Q000235:genetics*; D017930:Genes, Reporter; D015894:Genome, Human / Q000235:genetics; D057166:High-Throughput Screening Assays / Q000379:methods*; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008940:Mitotic Index; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D010770:Phosphotransferases / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D015203:Reproducibility of Results; D054852:Small Molecule Libraries / Q000032:analysis* / Q000494:pharmacology; D050257:Tubulin Modulators / Q000494:pharmacology
D018076:DNA, Complementary; D016189:Dystrophin; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D016376:Oligonucleotides, Antisense; D034741:RNA, Small Interfering; D054852:Small Molecule Libraries; D050257:Tubulin Modulators; C012589:trichostatin A; D008156:Luciferases; D010770:Phosphotransferases