Comparison of serum and urinary levels of modified nucleoside, 1-methyladenosine, in cancer patients using a monoclonal antibody-based inhibition ELISA

Tohoku J Exp Med. 1995 May;176(1):61-8. doi: 10.1620/tjem.176.61.

Abstract

To evaluate the clinical usefulness of serum 1-methyladenosine, several modifications have been made in our previously established inhibition ELISA system. Horseradish peroxidase (HRP) labeled anti-mouse IgG and 3,3',5,5'-tetramethylbenzidine (TMBZ) were used as a secondary antibody and a substrate, respectively. The second blocking was done just before the addition of the secondary antibody. The standard curve of the modified ELISA system showed good linearity between 1 and 1,000 ng/ml, and the detection limit was 50 pg/well. Using the ultrafiltrated-serum samples, serum 1-methyladenosine levels in healthy individuals and cancer patients were determined. The mean level of 1-methyladenosine in 31 healthy individuals was 28.3 +/- 7.9 ng/ml, and cut off value was set at 44.1 ng/ml (Mean+ 2SD). In cancer patients, elevated levels of serum 1-methyladenosine above the cut off value were detected in 4 out of 25 cases tested, though 11 cases had elevated urinary 1-methyladenosine levels above the cut off value (3.23 nmol/mumol creatinine). Since 1-methyladenosine has no interaction with serum proteins and its molecular weight is quite low, it might be rapidly excreted into the urine.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine / analogs & derivatives*
  • Adenosine / blood
  • Adenosine / urine
  • Adolescent
  • Adult
  • Aged
  • Antibodies, Monoclonal*
  • Enzyme-Linked Immunosorbent Assay / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoplasms / blood*
  • Neoplasms / urine*
  • Reference Values

Substances

  • Antibodies, Monoclonal
  • 1-methyladenosine
  • Adenosine