Cyclooxygenase-2 expression in human thyroid carcinoma and Hashimoto's thyroiditis.
OBJECTIVE
Cyclooxygenases (COX) are enzymes that catalyze the conversion of arachidonic acid to prostaglandins. COX-2, unlike the constitutively expressed COX-1, is an inducible enzyme upregulated during cell proliferation and inflammation. More recently, COX-2 has been implicated in the development of numerous types of epithelial cancers. In addition, COX-2 is highly expressed in several inflammatory diseases. Because of its dual role in inflammation and cancer, we were interested in determining if COX-2 plays a role in the development of human thyroid carcinoma and Hashimoto's thyroiditis, an autoimmune condition frequently associated with thyroid malignancy.


METHODS
Twenty paraffin-embedded human tissue specimens, including normal, inflammatory, and neoplastic thyroid sections, were analyzed by immunohistochemical staining for expression of human COX-2. In addition, COX-2 protein expression was verified by Western blot in two specimens.


RESULTS
Immunohistochemical staining confirmed the presence of COX-2 in thyroid epithelial neoplasms, including papillary and follicular carcinomas. Moreover, COX-2 expression was observed in patients with Hashimoto's thyroiditis. COX-2 expression, however, was not observed in normal thyroid tissue, multinodular goiter, or anaplastic carcinoma.


CONCLUSIONS
We have shown that cyclooxygenase-2 is expressed in thyroid carcinoma and thyroid epithelium from patients with Hashimoto's thyroiditis but not in normal thyroid. The expression of COX-2 in both of these thyroid pathologies may provide a basis for the relationship between carcinogenesis and autoimmunity.
Cornetta
Anthony J
AJ
Department of Otolaryngology--Head and Neck Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA. acornetta@earthlink.net
Russell
John P
JP
Cunnane
Mary
M
Keane
William M
WM
Rothstein
Jay L
JL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D001707:Biopsy, Needle; D015153:Blotting, Western; D002277:Carcinoma / Q000201:enzymology* / Q000473:pathology; D046508:Culture Techniques; D051546:Cyclooxygenase 2; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D011336:Probability; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000201:enzymology* / Q000473:pathology; D013967:Thyroiditis, Autoimmune / Q000201:enzymology* / Q000473:pathology
D014408:Biomarkers, Tumor; D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases