Labeling of phosphorothioate antisense oligonucleotides with yttrium-90.
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 90-Y-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.
Watanabe
N
N
Division of Advanced Technology for Medical Imaging, National Institute of Radiological Sciences, Chiba, Japan. w_nao@nirs.go.jp
Sawai
H
H
Endo
K
K
Shinozuka
K
K
Ozaki
H
H
Tanada
S
S
Murata
H
H
Sasaki
Y
Y
D001790:Blood Physiological Phenomena; D002474:Cell-Free System / Q000737:chemistry; D004492:Edetic Acid / Q000031:analogs & derivatives / Q000737:chemistry; D006801:Humans; D017879:Isothiocyanates / Q000737:chemistry; D016376:Oligonucleotides, Antisense / Q000737:chemistry*; D011854:Radiochemistry; D017422:Sequence Analysis, DNA; D013873:Thionucleotides / Q000737:chemistry*; D015021:Yttrium Radioisotopes
D017879:Isothiocyanates; D016376:Oligonucleotides, Antisense; D013873:Thionucleotides; D015021:Yttrium Radioisotopes; C119668:isothiocyanobenzyl ethylenediamine tetracetic acid; D004492:Edetic Acid