A unique c-myc-targeted triplex-forming oligonucleotide inhibits the growth of ovarian and cervical carcinomas in vitro.
A 27-base pair triplex forming oligonucleotide (G27-oligonucleotide) targeted to the "puf" regulatory protein-binding domain of the human c-myc oncogene has been conjugated with the DNA-binding molecule acridine (G27-conjugate) in order to obtain a drug with high binding affinity as well as high sequence specificity. Both the triplex-forming oligonucleotide and its acridine conjugate are shown to form triple-stranded DNA at the site of the target sequence by DNase 1 footprinting. When the cervical carcinoma cell line HeLa was exposed to 4 microM concentrations of the G27-oligonucleotide the viable cell count fell to 89, 56, and 49% of control at 25, 50, and 72 hr. After exposure to 1 microM G27-conjugate the viable cell count fell to 87, 50, and 33% of control. Nonspecific reductions in cell number were found for the control oligonucleotides to 79 and 82% of control. When SKOV-3 cells were exposed to the same concentrations of oligonucleotides, viable cell count in relation to control fell to 43, 50, and 67% with the G27-oligonucleotide and 57, 52, and 53% with the G27-conjugate at 24, 48, and 72 hr. The control oligonucleotides again caused a small nonspecific drop in the viable cell number.
Helm
C W
CW
Division of Gynecologic Oncology, University of Alabama, Birmingham 35294.
Shrestha
K
K
Thomas
S
S
Shingleton
H M
HM
Miller
D M
DM
D000166:Acridines / Q000138:chemical synthesis / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D001483:Base Sequence; D004273:DNA, Neoplasm / Q000187:drug effects*; D003850:Deoxyribonuclease I; D005260:Female; D016259:Genes, myc / Q000187:drug effects*; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000494:pharmacology*; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000473:pathology; D014407:Tumor Cells, Cultured; D002583:Uterine Cervical Neoplasms / Q000235:genetics* / Q000473:pathology
D000166:Acridines; D000970:Antineoplastic Agents; D004273:DNA, Neoplasm; D009841:Oligonucleotides; C081822:acridine-G-27 oligonucleotide; D003850:Deoxyribonuclease I