Elevated expression of cyclooxygenase-2 in adenocarcinoma of the parotid gland: insights into malignant transformation of pleomorphic adenoma.
Pleomorphic adenoma, the most common type of tumor of the parotid gland, may transform into a malignant tumor. In the current study, we investigated whether the expression of cyclooxygenase-2 (COX-2) is elevated in adenocarcinoma as compared to pleomorphic adenoma. Ten pleomorphic adenomas and 10 adenocarcinomas were examined. The tumor specimens were immunohistochemically stained with antibodies against COX-2 and Ki-67. The labeling indices of COX-2 in pleomorphic adenoma and adenocarcinoma were 6.0% +/- 4.1% and 16.1% +/- 4.6%, respectively, and those of Ki-67 in pleomorphic adenoma and adenocarcinoma were 0.77% +/- 0.62% and 6.9% +/- 6.6%, respectively. The labeling indices of both COX-2 and Ki-67 were significantly greater (p < .001) in adenocarcinoma than in pleomorphic adenoma. Together with the biological effects of COX-2, these results suggest that overexpression of COX-2 plays a crucial role in the pathogenesis of malignant transformation of pleomorphic adenoma in the parotid gland.
Sakamoto
Takashi
T
Dept of Otorhinolaryngology, Mutual Aid Association for Tokyo Metropolitan Teachers and Officials, Sanraku Hospital, Kandasurugadai 2-5, Chiyoda-ku, Tokyo 101-8326, Japan.
Kondo
Kenji
K
Yamasoba
Tatsuya
T
Sugasawa
Masashi
M
Kaga
Kimitaka
K
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology*; D008949:Adenoma, Pleomorphic / Q000473:pathology*; D000328:Adult; D000368:Aged; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D051546:Cyclooxygenase 2; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism*; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000378:metabolism* / Q000473:pathology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*
D007527:Isoenzymes; D019394:Ki-67 Antigen; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases