Triplex-forming oligonucleotide binding represses transcription of the human c-erbB gene in glioma.
Mixed purine-pyrimidine oligodeoxynucleotides were designed to form collinear DNA triplexes with pyrimidine-rich elements in the EGFR gene promoter. Their effects as mediators of human epidermal growth factor receptor (EGFR) gene transcription and subsequent gene expression were evaluated using human squamous cell carcinoma (A431) and human glioma cell line (U251MG and U87MG). Gel shift analysis indicated that the oligonucleotide forms a collinear triplex within the duplex Sp-1 binding site. An in vitro assay system revealed a correlation between triplex formation and the repression of EGFR transcription. We postulate that guanine residues are not always optimum in apposition to G-C pairs to form triple helices in the target. Site-specific oligodeoxynucleotides binding to a DNA duplex may serve as the basis for an alternative program of gene control in vitro.
Okada
T
T
Department of Neurosurgery, Kanazawa University School of Medicine, Japan.
Yamaguchi
K
K
Yamashita
J
J
D001483:Base Sequence; D001932:Brain Neoplasms / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism; D002460:Cell Line; D017931:DNA Primers; D066246:ErbB Receptors / Q000096:biosynthesis*; D015870:Gene Expression / Q000187:drug effects*; D018773:Genes, erbB-1; D005910:Glioma / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000494:pharmacology*; D016376:Oligonucleotides, Antisense / Q000737:chemistry / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D066246:ErbB Receptors