Immunohistochemical expression of COX-2 in thyroid nodules.
BACKGROUND
Recent evidence indicates that elevated COX-2 expression is associated with the carcinogenesis of numerous neoplasms. In this study, we investigated COX-2 expression in various thyroid specimens in order to elucidate its physiological role in pathologic conditions, and to evaluate the efficiency of COX-2 protein expression as a molecular marker of malignancy in the thyroid gland.


METHODS
COX-2 expression was studied immunohistochemically in 19 papillary carcinomas, 8 follicular carcinomas, 14 follicular adenomas, 2 Hürthle cell carcinomas, 4 Hürthle cell adenomas, 8 nodular hyperplasias, 3 Graves' diseases, 3 Hashimoto's thyroiditis, 2 medullary carcinomas, 1 anaplastic carcinoma, and 20 normal thyroid tissues.


RESULTS
COX-2 staining was not seen in any of the normal thyroid, Graves' disease, or nodular hyperplasia specimens. In contrast, COX-2 staining was observed in all of papillary carcinomas, Hashimoto's thyroiditis, Hürthle cell carcinomas, and Hürthle cell adenomas tissues. Moreover, 7 of 8 follicular carcinomas and 11 of 14 follicular adenomas showed COX-2 staining.


CONCLUSIONS
These results indicate that COX-2 is not useful as a marker of malignancy. Since COX-2 expression was evident in follicular adenomas and in papillary and follicular carcinomas. Thus, the enzyme may be involved in the early process of thyroid tumorigenesis.
Kim
Sang Jin
SJ
Department of Internal Medicine, Soonchunhyang University Medical College, Cheonan, Korea. ksj1113@schch.co.kr
Lee
Jae Hak
JH
Yoon
Ji Sung
JS
Mok
Ji O
JO
Kim
Yeo Joo
YJ
Park
Hyeong Kyu
HK
Kim
Chul Hee
CH
Byun
Dong Won
DW
Suh
Kyo Il
KI
Yoo
Myung Hi
MH
D014408:Biomarkers, Tumor / Q000032:analysis*; D051546:Cyclooxygenase 2; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis*; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis*; D016606:Thyroid Nodule / Q000201:enzymology* / Q000473:pathology*
D014408:Biomarkers, Tumor; D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases