A thyroid cancer specific monoclonal antibody which recognizes cryptic epitope(s) of human thyroglobulin.
A monoclonal antibody (TCM-9) specific for human thyroid cancer but not for Graves' disease, adenoma or normal thyroid tissue was shown to recognize a 300 K protein but not to bind to native or mature human thyroglobulin (Tg). In this study, we investigated further the antigen recognized by TCM-9. When purified Tg was treated with periodate, dithiothreitol (DTT) and sodium dodecyl sulfate (SDS), immunoblotting of treated Tg with TCM-9 revealed an apparent enhancement of the staining only with DTT-treated Tg. Furthermore, the DTT-treated Tg was shown to bind dose-dependently to plates coated with TCM-9. We performed SDS-PAGE and immunoblot analyses on the immune complex obtained from a homogenate of thyroid cancer tissue which was preincubated with an excess of anti-Tg monoclonal antibody. When the protein was autoradiographed with [125I]TCM-9, a definite band was observed. The results indicate that TCM-9 is likely to be directed against a masked epitope of thyroglobulin which can be exposed after treatment with a reducing agent.
Sugawa
H
H
Department of Laboratory Medicine, Kyoto University School of Medicine, Japan.
Smith
E
E
Imura
H
H
Mori
T
T
D000230:Adenocarcinoma / Q000276:immunology*; D000236:Adenoma / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000912:Antibodies, Neoplasm / Q000276:immunology*; D000918:Antibody Specificity; D000951:Antigens, Neoplasm / Q000276:immunology*; D002291:Carcinoma, Papillary / Q000276:immunology*; D002462:Cell Membrane / Q000276:immunology; D003429:Cross Reactions; D004229:Dithiothreitol / Q000494:pharmacology; D000939:Epitopes / Q000187:drug effects / Q000276:immunology*; D006031:Glycosylation; D006111:Graves Disease / Q000276:immunology; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C / Q000276:immunology; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000276:immunology*; D013954:Thyroglobulin / Q000187:drug effects / Q000276:immunology*; D013964:Thyroid Neoplasms / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D000939:Epitopes; D009363:Neoplasm Proteins; D013954:Thyroglobulin; D004229:Dithiothreitol