title: Targeting MDR1 gene: synthesis and cellular study of modified daunomycin-triplex-forming oligonucleotide conjugates able to inhibit gene expression in resistant cell lines.
abstract: Reversal of the multidrug-resistant (MDR) phenotype is very important for chemotherapy success. In fact, the expression of the MDR1 gene-encoded P-glycoprotein (P-gp) actively expels antitumor agents such as daunomycin (DNM) out of the cells, resulting in drug resistance. We show that upon conjugation to triplex-forming oligonucleotides, it is possible to address DNM in resistant cells (MCF7-R and NIH-MDR-G185). The oligonucleotide moiety of the conjugate changes the cellular penetration properties of the antitumor agent that is no more the target of P-gp in resistant cells. We observe an accumulation of conjugated DNM in cells up to 72 h. For more efficient delivery in the cells' nuclei, transfectant agents must be used. In addition, the conjugate recognizes a sequence located in exon 3 of MDR1, and it inhibits its gene expression as measured both by Western blot and by reverse transcription-polymerase chain reaction.
authors.affiliation: Unité Mixte de Recherche 5153 Centre National de la Recherche Scientifique-MNHN USM0503, Institut National de la Santé et de la Recherche Médicale UR565, 43 rue Cuvier, 75005 Paris, France.
authors.forename: Vérène
authors.initials: V
authors.lastname: Stierlé
authors.forename: Maria
authors.initials: M
authors.lastname: Duca
authors.forename: Ludovic
authors.initials: L
authors.lastname: Halby
authors.forename: Catherine
authors.initials: C
authors.lastname: Senamaud-Beaufort
authors.forename: Massimo L
authors.initials: ML
authors.lastname: Capobianco
authors.forename: Alain
authors.initials: A
authors.lastname: Laigle
authors.forename: Béatrice
authors.initials: B
authors.lastname: Jollès
authors.forename: Paola B
authors.initials: PB
authors.lastname: Arimondo
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D004247:DNA / Q000138:chemical synthesis / Q000494:pharmacology*; D003630:Daunorubicin / Q000737:chemistry / Q000494:pharmacology*; D015536:Down-Regulation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D024202:Electrophoretic Mobility Shift Assay; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D009841:Oligonucleotides / Q000138:chemical synthesis* / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence; D014162:Transfection
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D009841:Oligonucleotides; C051802:triplex DNA; D004247:DNA; D003630:Daunorubicin