Production of a Novel Monoclonal Antibody, JT-95, Which Can Detect Antigen of Thyroid Carcinoma

Monoclonal antibody (MAb) JT-95 was produced by immunization of mice with membrane fractions of a human thyroid carcinoma. Immuno-histochemical staining has demonstrated that the antigen recognized by JT-95 is strongly expressed in 95 (95%) of 100 cases of papillary carcinomas and in 3 (75%) of 4 cases of follicular carcinomas. In benign diseases of the thyroid gland, MAb JT-95 reacted with 0 (0%) of 39 adenomas, 1 (4%) of 21 adenomatous goiters, 0 (0%) of 8 hyperthyroidism specimens, and 3 (38%) of 8 chronic thyroiditis specimens. The antigen detected by MAb JT-95 has an apparent M r 250,000 in thyroid carcinomas. Moreover, circulating antigen in thyroid carcinoma patients was detected using MAb JT-95 in an ELISA and in Western blotting. The circulating antigen has a M r 105,000. MAb JT-95 conjugated with 131 I was administrated to nude mice bearing a human thyroid carcinoma. JT-95 131 I accumulation at the transplanted tumor was visualized by autoradiography with 2.68-14.75-fold higher levels detected at the xenograft compared to that for normal organs. Based on these data, MAb JT-95 may be useful in the diagnosis detection and therapy of thyroid carcinoma.