Cyclooxygenase-2 in normal, hyperplastic and neoplastic follicular cells of the human thyroid gland.
This study was undertaken to investigate cyclooxygenase-2 (COX-2) expression in follicular cells of the human thyroid. COX-2 expression was studied immunohistochemically in a total of 174 samples. COX-2 immunoreactivity was confined to the cell cytoplasm with the nuclei remaining unlabelled. COX-2 expression was observed in five cases (17.2%) of normal follicular cells and in one case (16.6%) of solid cell nests. Follicular carcinoma expressed COX-2 more frequently than follicular adenoma (93.4% vs 21.1%) (p<or=0.001). A higher percentage of cases of papillary microcarcinomas up-regulated COX-2 in comparison with all papillary carcinomas (p<or=0.05). However, we could not establish any relationships among COX-2, patients' ages or lymph node metastases in papillary carcinomas. COX-2 expression was found in 12 (92.3%) poorly differentiated carcinomas and in 13 (92.8%) undifferentiated carcinomas. We found that COX-2 is not always useful as a marker of malignancy. Our results suggest that COX-2 plays a role in progression of all thyroid carcinomas, but in papillary carcinomas, seems more important only in the early stages. COX-2 expression in the undifferentiated carcinoma deserves special consideration due to its prognosis and to the fact that selective COX-2 inhibitors were found to enhance tumour response to radiation in some studies.
García-González
Miguel
M
Department of Nephrology, Hospital Clínico Universitario, Choupana s/n, 15706, Santiago de Compostela, Spain.
Abdulkader
Ihab
I
Boquete
Angel Vázquez
AV
Neo
Xosé Manuel Lens
XM
Forteza
Jerónimo
J
Cameselle-Teijeiro
José
J
D000236:Adenoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D018265:Carcinoma, Papillary, Follicular / Q000201:enzymology* / Q000556:secondary; D051546:Cyclooxygenase 2; D004273:DNA, Neoplasm / Q000032:analysis; D006801:Humans; D006965:Hyperplasia / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D013961:Thyroid Gland / Q000201:enzymology* / Q000473:pathology; D013964:Thyroid Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology
D004273:DNA, Neoplasm; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases