Characterization of a 90-100 kDa tumor-associated antigen in the sera of melanoma patients.
Using allogeneic antibody, we previously described a high-molecular-weight glycoprotein in the urine of 68% of melanoma patients. This glycoprotein has been termed urinary-tumor-associated antigen (U-TAA). A murine monoclonal antibody (MAb) specific for U-TAA (ADI-40F4) has been developed. By the use of ADI-40F4, U-TAA was detected in serum samples from 63% (33/52) of stage II and stage III melanoma patients, but from only 5% (1/20) of normal controls. This report describes the physical and immunochemical properties of U-TAA in the serum. The antigen elutes from a DEAE-Sephacel column in association with IgG in the void volume and as free antigen in a second peak. The molecular mass of the free antigen is 590-620 kDa and it sediments in the region of 28-29% sucrose by density gradient ultracentrifugation. Free antigen has an isoelectric point of 6.1. This high molecular weight antigen is composed of smaller subunits linked by reducible bonds. The ADI-40F4 reactive epitope resides on a 90-100 kDa subunit. These results provide evidence that U-TAA which is produced by melanoma cells in vitro is present in the circulation of melanoma patients.
Euhus
D M
DM
Division of Surgical Oncology, Armand Hammer Laboratories, John Wayne Cancer Clinic, UCLA School of Medicine 90024.
Gupta
R K
RK
Morton
D L
DL
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000097:blood* / Q000302:isolation & purification / Q000652:urine; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D007525:Isoelectric Focusing; D008207:Lymphatic Metastasis; D008545:Melanoma / Q000276:immunology* / Q000652:urine; D008562:Membrane Glycoproteins / Q000097:blood* / Q000276:immunology* / Q000302:isolation & purification / Q000652:urine; D008970:Molecular Weight; D014461:Ultracentrifugation
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D008562:Membrane Glycoproteins; C114782:TAA90K protein, human