[Current status and prospects for targeted therapy for thyroid cancer].
New strategies are currently being developed with regard to targeted (missile) therapy for cancer using anticancer agent-labeled specific antibodies. A range of problems prevent their clinical application, however, because each specific cancer may not yet have a known unique antigen. In turn, this serves to impede the development of specific antibodies. Regarding thyroid cancer, no reports of targeted therapy have appeared since specific antigens remain to be identified. Monoclonal antibodies A2B5, HISL-19 and 4F2 bind to neuroendocrine tumors (A2B5, HISL-19) and severe malignant tumors (4F2) indicating rapid growth, enabling these tumors to express common anti-genetic determinants to our monoclonal antibodies. The immunohistochemical study for thyroid cancers revealed that A2B5 and HISL-19 only react with medullary carcinoma and that 4F2 only reacts with anaplastic carcinoma. When 131I-labeled A2B5 was injected into the rat bearing insulinoma, the antigen of which is common to medullary carcinoma of the thyroid, clear accumulation of radiolabeled antibody corresponding to the transplanted tumor was observed by scintiscanning. Furthermore, the biochemical study undertaken to identify anti-genetic protein using the Western blotting procedure demonstrated new HISL-19 antigen in medullary carcinoma of the thyroid, which is not recognized in benign endocrine tumor, and 4F2 antigen in anaplastic carcinoma. Since these antigens do not circulate in the blood stream, the administered antibody reaches the targeted lesion without decreasing antibody titer. Although many problems remain, such as the effect on normal cells and affinity to the targeted lesion, our current aim is to establish an efficient and effective chemotherapy using monoclonal antibodies in medullary carcinoma and anaplastic carcinoma arising in the thyroid.
Shimizu
K
K
Second Dept. of Surgery, Nippon Medical School.
Mimura
T
T
Harada
T
T
Tanaka
S
S
D000236:Adenoma / Q000628:therapy; D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D006042:Goiter / Q000628:therapy; D006801:Humans; D000922:Immunotoxins / Q000008:administration & dosage*; D007340:Insulinoma / Q000628:therapy; D015458:Leukemia, T-Cell / Q000628:therapy; D051379:Mice; D018358:Neuroendocrine Tumors / Q000628:therapy; D010190:Pancreatic Neoplasms / Q000628:therapy; D051381:Rats; D013964:Thyroid Neoplasms / Q000628:therapy*
D000911:Antibodies, Monoclonal; D000970:Antineoplastic Agents; D000922:Immunotoxins