title: Pharmacokinetics of (111)In-labeled triplex-forming oligonucleotide targeting human N-myc gene.
abstract: The radiolabeled triplex-forming oligonucleotide (TFO) demonstrated the potential for sequence-specific DNA binding and destruction. In this study, by selecting the polypurine-polypyrimidine stretch (2950-2978) in the human N-myc gene as a target, the (111)In-labeled TFO targeting human N-myc gene (N-mycTFO(111)In) was tested for its cellular uptake and nuclear localization in vitro and in vivo. This is because the deregulated N-myc expression is strongly implicated in the pathogenesis of several important human malignancies, including breast carcinoma and neuroblastoma. N-mycTFO(111)In was bound selectively to the N-myc sequence in vitro. The total cellular uptake of TFO after the incubation of various normal and cancer cells with TFO for 24 h was 20-54.8% of the injected dose (%ID), and the nuclear localization was 6.59-30.0%ID, depending on cell lines. The highest cellular uptake was found in the human neuroblastoma SK-N-DZ (54.8%ID), human mammary ductal carcinoma T47-D (54%ID), human acute T cell leukemia Jurkat (54%ID), and multidrug-resistant human breast adenocarcinoma MCF7/TH (49.5%ID). The lowest was in the human normal mammary epithelium MCF10A (20.0%ID). The highest nuclear localization was found in MCF7/TH (30%ID) and SK-N-DZ (28.7%ID). The lowest was in MCF11A (6.59%ID). We next injected TFO into human mammary tumor-xenografted Balb/c nude mice. Tumor targeting of TFO in vivo reached its maximum peak 5 h after the intravenous injection in three types of tumor models. They are 21.0 +/- 3.23%ID per gram of tissue (%ID/g) for MCF7/TH, 7.77 +/- 2.11%ID/g for MCF7, and 4.53 +/- 1.20%ID/g for MCF10A. The TFO blood level decreased from 8.00 +/- 0.90%ID/g 15 min after the injection, to 1.30 +/- 0.30%ID/g after 19 h. The kidney TFO level increased rapidly from 5.93 +/- 0.94%ID/g after 15 min, to 25.1 +/- 5.60%ID/g after 19 h. A high TFO level (19.7-24.5%ID/g) in the liver was maintained until 19 h after the injection. Therefore, we suggest that the (111)In-labeled N-myc-targeting TFO, a promising modality for nanoexplosive gene therapy, could effectively target the nucleus of the multidrug-resistant breast carcinoma MCF7/TH in vitro and in vivo. It has approximately 130 min of half-life of blood TFO.
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Medicine, Korea University, Seoul.
authors.forename: Jae Gol
authors.initials: JG
authors.lastname: Cho
authors.forename: Meyoung-Kon
authors.initials: MK
authors.lastname: Kim
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Oh
authors.forename: Eun Jeong
authors.initials: EJ
authors.lastname: Yoon
authors.forename: Jeongwon
authors.initials: J
authors.lastname: Sohn
authors.forename: Min Kyu
authors.initials: MK
authors.lastname: Park
authors.forename: Gil Hong
authors.initials: GH
authors.lastname: Park
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D005260:Female; D016259:Genes, myc; D006801:Humans; D007205:Indium Radioisotopes; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009841:Oligonucleotides / Q000493:pharmacokinetics*; D004369:Pentetic Acid / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D007205:Indium Radioisotopes; D009841:Oligonucleotides; C051802:triplex DNA; D004369:Pentetic Acid; D004247:DNA