In vivo transcription of a progesterone-responsive gene is specifically inhibited by a triplex-forming oligonucleotide

• Published in: Nucleic acids research 1993-06, Vol.21 (12), p.2789-2796
• Main Authors: Ing, Nancy H., Beekman, Johanna M., Kessler, Donald J., Murphy, Mark, Jayaraman, Krishna, Zendegui, Joseph G., Hogan, Michael E., O'Malley, Bert W., Tsai, Ming-Jer
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; Binding Sites; Biological and medical sciences; Cell Line; Cholesterol - pharmacology; DNA - metabolism; DNA, Single-Stranded - chemistry; DNA, Single-Stranded - metabolism; DNA, Single-Stranded - pharmacology; ErbB Receptors - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression - drug effects; Haplorhini; Humans; Hydrogen-Ion Concentration; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Nucleic Acid Conformation; Progesterone - pharmacology; Promoter Regions, Genetic; Receptors, Progesterone - metabolism; Transcription, Genetic - drug effects; Transcription. Transcription factor. Splicing. Rna processing
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/21.12.2789

Oligonucleotides provide novel reagents for Inhibition of gene expression because of their high affinity binding to specific nucleotide sequences. We describe a 38 base, single-stranded DNA that forms a triple helix or ‘triplex’ on progesterone response elements of a target gene. This triplex-forming oligonucleotide binds with a Kd= 100 nM at 37°C and physiological pH, and blocks binding of progesterone receptors to the target. Furthermore, It completely inhibited progesterone receptor-dependent transcription In vitro. To approach In vivo conditions, triplex-forming ollgonucleotides were tested In cell transfection studies. The derivation of the oligonucleotides with cholesterol enhanced their cellular uptake and nuclear concentration by at least four-fold. The cholesterol-derivatized triplex-forming oligonucleotide specifically inhibited transcription of the PRE-containing reporter gene in cells when applied to the medium at micromolar concentrations. This Is the first demonstration of steroid-responsive gene inhibition by triplex formation and joins the growing body of evidence Indicating that oligonucleotides have therapeutic potential.