Labeling of phosphorothioate antisense oligonucleotides with yttrium-90

• Published in: Nuclear medicine and biology 1999-02, Vol.26 (2), p.239-243
• Main Authors: Watanabe, Naoyuki, Sawai, Hiroaki, Endo, Keigo, Shinozuka, Kazuo, Ozaki, Hiroaki, Tanada, Shuji, Murata, Hajime, Sasaki, Yasuhito
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Blood Physiological Phenomena; Cell-Free System - chemistry; Contrast media. Radiopharmaceuticals; Edetic Acid - analogs & derivatives; Edetic Acid - chemistry; Humans; Isothiocyanates - chemistry; Medical sciences; N- myc gene; oligonucleotides; Oligonucleotides, Antisense - chemistry; Pharmacology. Drug treatments; phosphorothioate; Phosphorothioate antisense oligonucleotide; Radiochemistry; Radiotherapy; SCN-Bn-EDTA; Sequence Analysis, DNA; Thionucleotides - chemistry; Yttrium Radioisotopes; Yttrium-90
• ISSN: 0969-8051; 1872-9614
• DOI: 10.1016/S0969-8051(98)00092-4

Novel yttrium-90 ( 90Y)-labeled phosphorothioate antisense oligonucleotides were designed as a potential targeted radionuclide therapeutic agent for malignant tumors. A 15-mer phosphorothioate antisense oligonucleotide, which was complementary to the translation start region of the N- myc oncogene mRNA, was conjugated with isothiocyanobenzyl ethylenediamine tetraacetic acid (SCN-Bn-EDTA), via a C-5-substituted deoxyuridine that had replaced a thymine in the oligonucleotide, and was then labeled with 90Y-acetate. Following purification, the radiochemical purity of the 90Y-Bn-EDTA-phosphorothioate antisense oligonucleotides was estimated by 2.0% agarose gel electrophoresis, and the specific hybridization of 90Y-Bn-EDTA-phosphorothioate antisense oligonucleotide to a phosphorodiester sense oligonucleotide was investigated by 20% polyacrylamide gel electrophoresis in a cell-free system. Radiochemical purity was 98.7 ± 0.4% at 72 h after labeling and 90.3 ± 0.9% after 72-h incubation with human normal serum. The 90Y-Bn-EDTA-phosphorothioate antisense oligonucleotide hybridized specifically to a complementary phosphorodiester sense oligonucleotide. In conclusion, phosphorothioate antisense oligonucleotides can be labeled stably with 90Y using SCN-Bn-EDTA without loss of hybridization properties.