title: Strategies for inhibition of MDR1 gene expression.
abstract: Several distinct strategies have been used to modulate the expression of cancer-associated genes, including antisense oligonucleotides, small interfering RNAs (siRNAs), and artificial transcriptional factors. One major cause for chemotherapeutic treatment failure in cancer is the overexpression of P-glycoprotein, the product of the multidrug resistance gene MDR1. In this study, we tested the ability of siRNAs to inhibit MDR1 gene expression. We evaluated the efficiency of chemically synthesized dsRNAs as well as vector-based hairpin siRNAs and investigated the behavior of clones of multidrug-resistant NCI/ADR-RES breast carcinoma cells stably transfected with hairpin siRNA vectors. The effects of siRNA on the MDR phenotype were compared with those elicited by antisense oligonucleotides or by designed transcription factors targeting the MDR1 promoter. These studies suggest that there are several comparably effective strategies for inhibiting MDR1 expression.
authors.affiliation: Department of Pharmacology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Dong
authors.initials: D
authors.lastname: Xu
authors.forename: Hyunmin
authors.initials: H
authors.lastname: Kang
authors.forename: Michael
authors.initials: M
authors.lastname: Fisher
authors.forename: R L
authors.initials: RL
authors.lastname: Juliano
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D018432:Drug Resistance, Multiple / Q000187:drug effects* / Q000502:physiology; D015870:Gene Expression / Q000187:drug effects*; D019450:Genes, MDR / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D034741:RNA, Small Interfering / Q000494:pharmacology*; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D016376:Oligonucleotides, Antisense; D034741:RNA, Small Interfering