Labeling of phosphorothioate antisense oligonucleotides with yttrium-90

Nucl Med Biol. 1999 Feb;26(2):239-43. 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 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.

MeSH terms

  • Blood Physiological Phenomena
  • Cell-Free System / chemistry
  • Edetic Acid / analogs & derivatives
  • Edetic Acid / chemistry
  • Humans
  • Isothiocyanates / chemistry
  • Oligonucleotides, Antisense / chemistry*
  • Radiochemistry
  • Sequence Analysis, DNA
  • Thionucleotides / chemistry*
  • Yttrium Radioisotopes


  • Isothiocyanates
  • Oligonucleotides, Antisense
  • Thionucleotides
  • Yttrium Radioisotopes
  • isothiocyanobenzyl ethylenediamine tetracetic acid
  • Edetic Acid