title: Antiproliferative effects of steric blocking phosphorodiamidate morpholino antisense agents directed against c-myc.
abstract: The phosphorodiamidate Morpholino oligomers (PMO) are a new class of antisense agents that inhibit gene expression by binding to RNA and sterically blocking processing or translation. In a search for a Morpholino agent that would inhibit cell proliferation, it was found that oligomers directed against c-myc, a gene involved in control of the cell cycle, were effective. The sequence specificity and mechanism of action of one agent were determined. The 20-mer 126 lowers c-myc protein levels in treated cells and arrests cells in G0/G1 of the cell cycle. It also acts at the RNA level to inhibit normal pre-mRNA splicing and instead produces an aberrantly spliced mRNA. Irrelevant and mispair control oligomers indicated that the observed antiproliferative effect was sequence specific. This was confirmed in a reporter gene model system using a c-myc 5'-untranslated region (5'-UTR) fused to a cDNA copy of the insect luciferase gene. We conclude that 126 is acting through an antisense mechanism involving Watson-Crick hydrogen bonding to its target RNA. A specific antisense agent directed against a cell cycle-associated gene mRNA may be useful as a therapeutic in diseases characterized by excess cell proliferation, such as restenosis following balloon angioplasty or cancer.
authors.affiliation: Department of Biology, AVI BioPharma, Inc., Corvallis, OR 97333, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Hudziak
authors.forename: J
authors.initials: J
authors.lastname: Summerton
authors.forename: D D
authors.initials: DD
authors.lastname: Weller
authors.forename: P L
authors.initials: PL
authors.lastname: Iversen
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002461:Cell Line, Transformed / Q000166:cytology / Q000187:drug effects; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016259:Genes, myc / Q000187:drug effects*; D006131:Growth Inhibitors / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D009025:Morpholines / Q000494:pharmacology*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D051381:Rats; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D013873:Thionucleotides / Q000494:pharmacology
chemical_list: D006131:Growth Inhibitors; D009025:Morpholines; D016376:Oligonucleotides, Antisense; D016271:Proto-Oncogene Proteins c-myc; D013873:Thionucleotides