title: Potent growth inhibition of leukemic cells by novel ribbon-type antisense oligonucleotides to c-myb1.
abstract: We studied the effects of antisense oligonucleotides (AS oligos) with a novel structure. The AS oligos were covalently closed to avoid exonuclease activities by enzymatic ligation of two identical molecules. The AS oligos of a ribbon type (RiAS oligos) consist of two loops containing multiple antisense sequences and a stem connecting the two loops. Three antisense sequences targeting different binding sites were placed in a loop that was designed to form a minimal secondary structure by itself. RiAS oligos were found to be stable because they largely preserved their structural integrity after 24 h incubation in the presence of either exonuclease III or serums. When a human promyelocytic cell line, HL-60, was treated with RiAS oligos to c-myb, c-myb expression was effectively ablated. Cell growth was inhibited by >90% determined by both the 3-[4,5-dimethythiazol-2-yl]-2,5-diphenyltetrazolium bromide assay and [(3)H]thymidine incorporation. Further, when the leukemic cell line K562 was treated with c-myb RiAS oligos, colony formation on soft agarose was reduced by 92 +/- 2%. These results suggest that RiAS oligos may be employed for developing molecular antisense drugs as well as for the functional study of a gene.
authors.affiliation: Institute for Medical Science, Keimyung University Dongsan Medical Center, 194 Dongsandong, Joonggu, Taegu 700-712, South Korea.
authors.forename: I J
authors.initials: IJ
authors.lastname: Moon
authors.forename: K
authors.initials: K
authors.lastname: Choi
authors.forename: Y K
authors.initials: YK
authors.lastname: Choi
authors.forename: J E
authors.initials: JE
authors.lastname: Kim
authors.forename: Y
authors.initials: Y
authors.lastname: Lee
authors.forename: A D
authors.initials: AD
authors.lastname: Schreiber
authors.forename: J G
authors.initials: JG
authors.lastname: Park
mesh_terms: D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects*; D018922:HL-60 Cells; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000473:pathology*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016376:Oligonucleotides, Antisense / Q000737:chemistry / Q000494:pharmacology*; D020598:Proto-Oncogene Proteins c-myb / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D016376:Oligonucleotides, Antisense; D020598:Proto-Oncogene Proteins c-myb; D012333:RNA, Messenger