Preparation of a monoclonal antibody specific for 1-methyladenosine and its application for the detection of elevated levels of 1-methyladenosine in urines from cancer patients.
A monoclonal antibody specific for a modified nucleoside, 1-methyladenosine, was prepared and characterized. This antibody, termed AMA-2, reacts with 1-methyladenosine and 1-methyladenine but not with other nucleosides, particularly methylated adenosines other than 1-methyladenosine and methylated guanosines, tested in this investigation. In our experiments, AMA-2 was used in an enzyme-linked immunosorbent assay (ELISA) system for the quantitation of the levels of 1-methyladenosine in urine. Sensitivity was in the picomole range and accuracy was nearly equal to that of the high-performance liquid chromatography (HPLC) assay system. Urinary levels of 1-methyladenosine in healthy donors and patients with various advanced cancers were determined by the inhibition ELISA. The amount of 1-methyladenosine in urine of 33 healthy donors was 1.91 +/- 0.66 nmol/mumol creatinine. In 54% (51/94) of patients, urinary 1-methyladenosine was elevated above the mean plus 2 standard deviations for the healthy donors (3.23 nmol/mumol creatinine). In patients with leukemia, esophageal cancer, stomach cancer, colon cancer, and bladder cancer, urinary levels of 1-methyladenosine were significantly elevated. In patients with leukemia, urinary 1-methyladenosine levels changed almost in parallel with the change in the clinical response during chemotherapy. These results suggest that urinary 1-methyladenosine might be useful in monitoring the effectiveness of therapy.
D000241:Adenosine / Q000031:analogs & derivatives* / Q000276:immunology / Q000652:urine; D000911:Antibodies, Monoclonal; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D009369:Neoplasms / Q000652:urine*; D011863:Radioimmunoassay
D000911:Antibodies, Monoclonal; C002230:1-methyladenosine; D000241:Adenosine