title: Inhibiting gene expression with locked nucleic acids (LNAs) that target chromosomal DNA.
abstract: Oligonucleotides containing locked nucleic acid bases (LNAs) have increased affinity for complementary DNA sequences. We hypothesized that enhanced affinity might allow LNAs to recognize chromosomal DNA inside human cells and inhibit gene expression. To test this hypothesis, we synthesized antigene LNAs (agLNAs) complementary to sequences within the promoters of progesterone receptor (PR) and androgen receptor (AR). We observed inhibition of AR and PR expression by agLNAs but not by analogous oligomers containing 2'-methoxyethyl bases or noncomplementary LNAs. Inhibition was dose dependent and exhibited IC50 values of <10 nM. Efficient inhibition depended on the length of the agLNA, the location of LNA bases, the number of LNA substitutions, and the location of the target sequence within the targeted promoter. LNAs targeting sequences at or near transcription start sites yielded better inhibition than LNAs targeting transcription factor binding sites or an inverted repeat. These results demonstrate that agLNAs can recognize chromosomal target sequences and efficiently block gene expression. agLNAs could be used for gene silencing, as cellular probes for chromosome structure, and therapeutic applications.
authors.affiliation: Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, 6001 Forest Park Road, Dallas, Texas 75390-9041, USA.
authors.forename: Randall L
authors.initials: RL
authors.lastname: Beane
authors.forename: Rosalyn
authors.initials: R
authors.lastname: Ram
authors.forename: Sylvie
authors.initials: S
authors.lastname: Gabillet
authors.forename: Khalil
authors.initials: K
authors.lastname: Arar
authors.forename: Brett P
authors.initials: BP
authors.lastname: Monia
authors.forename: David R
authors.initials: DR
authors.lastname: Corey
mesh_terms: D059002:Androgen Receptor Antagonists; D001483:Base Sequence; D001943:Breast Neoplasms / Q000473:pathology; D045744:Cell Line, Tumor; D002875:Chromosomes / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D018390:Gene Targeting; D006801:Humans; D020128:Inhibitory Concentration 50; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009696:Nucleic Acids / Q000737:chemistry* / Q000494:pharmacology*; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry; D011401:Promoter Regions, Genetic; D011944:Receptors, Androgen / Q000235:genetics; D011980:Receptors, Progesterone / Q000037:antagonists & inhibitors / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014162:Transfection
chemical_list: D059002:Androgen Receptor Antagonists; D009696:Nucleic Acids; D009841:Oligonucleotides; D011944:Receptors, Androgen; D011980:Receptors, Progesterone; D004247:DNA