cysteinyldopa and Neoplasms

Polyamines (putrescine, spermidine and spermine) play important roles in cell proliferation and differentiation, and have been established as tumors markers. We and other workers have confirmed that N1-acetylspermidine in tumor tissues, spermidine and spermine in erythrocytes, and N1,N12-diacetylspermine in urine might be the most sensitive indicators for various forms of tumors. Neopterin is a marker of cell-mediated immunostimulation, and may be a helpful marker in monitoring cancer patients. HPLC and immunological assays of neopterin, biopterin, and N2-(3-aminopropyl)biopterin(oncopterin) in urine might be useful in the clinical study of pteridines, as cancer markers. Serum 5-S-cysteinyldopa level is a useful and specific biochemical marker for malignant melanoma.

Topics: Biomarkers, Tumor; Biopterins; Cysteinyldopa; Humans; Melanoma; Neoplasms; Neopterin; Polyamines

This study reports our success in developing a murine monoclonal antibody (mAb) against phaeomelanin and its major precursor, 5-S-cysteinyldopa (5-S-CD). A competitive enzyme-linked immunosorbent assay was developed and demonstrated that the new mAb, designated as 6D4 (IgG1, kappa), reacted with both 5-S-CD and phaeomelanin, but not with eumelanin. The concentrations required for 50% inhibition of 5-S-CD and phaeomelanin were 65 ng/ml and 95 ng/ml respectively. The minimal amount of 5-S-CD and phaeomelanin which could be detected by mAb 6D4 was approximately 5 and 6 ng/ml, respectively. The immunohistochemical assay indicated that the antigenic epitope(s) recognized by mAb 6D4 was localized in the cytoplasm of certain types of melanocytic tumours, such as superficial spreading melanoma.

Topics: Animals; Antibodies, Monoclonal; Antibody Specificity; Binding, Competitive; Cysteinyldopa; Enzyme-Linked Immunosorbent Assay; Humans; Hybridomas; Immunoglobulin G; Melanins; Melanoma; Mice; Mice, Inbred BALB C; Neoplasms; Nevus, Pigmented; Rats; Skin Neoplasms; Tumor Cells, Cultured