title: Effect of unmodified triple helix-forming oligodeoxyribonucleotide targeted to human multidrug-resistance gene mdr1 in MDR cancer cells.
abstract: The human mdr1 gene encodes a transmembrane glycoprotein the over-expression of which is associated with development of multidrug resistance in human tumor cells. A negative modulation of human mdr1 has been attempted via a 27-mer unmodified triple helix-forming oligonucleotide, named 1D, targeted to a homopurine sequence in the coding region of the gene. By administering 10 microM of 1D we could find a significant reduction in MDR1 mRNA levels in the human drug-resistant cell line CEM-VLB100. This effect appears to be specific and due to a transient block of RNA polymerase mediated by triple helix formation.
authors.affiliation: Department of Biomedical Sciences and Technologies, University of Udine, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Scaggiante
authors.forename: C
authors.initials: C
authors.lastname: Morassutti
authors.forename: G
authors.initials: G
authors.lastname: Tolazzi
authors.forename: A
authors.initials: A
authors.lastname: Michelutti
authors.forename: M
authors.initials: M
authors.lastname: Baccarani
authors.forename: F
authors.initials: F
authors.lastname: Quadrifoglio
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D002460:Cell Line; D018432:Drug Resistance, Multiple / Q000235:genetics*; D006801:Humans; D007938:Leukemia; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000187:drug effects; D013873:Thionucleotides; D014407:Tumor Cells, Cultured
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D013873:Thionucleotides