Simultaneous expression of cyclooxygenase-2 and microsomal prostaglandin E synthase in squamous cell carcinoma of the larynx.
CONCLUSIONS
In laryngeal cancer, arachidonic acid may be metabolized to PGE2 via the cooperative actions of COX-2 and mPGES, which are induced in response to various stimuli. The COX-2-mPGES-PGE2 system may induce differentiation of cancer cells and prevent metastasis, thus improving the survival rate.


OBJECTIVE
To examine the expression of COX-1, COX-2, and two downstream enzymes--microsomal PGE synthase (mPGES) and PGD synthase (PGDS)--using immunohistochemistry in human laryngeal squamous cell carcinoma (SCC).


METHODS
Patients with laryngeal carcinoma were referred to the Department of Otolaryngology for treatment. Formalin-fixed, paraffin-embedded laryngeal carcinoma specimens were obtained from 24 patients. Immunohistochemical expression of COX-1, COX-2, mPGES, LPGDS, and HPGDS was investigated in 24 laryngeal carcinoma samples.


RESULTS
Among the carcinomas, cytoplasmic immunoreactivity for COX-2 was found in tumor cells in 18 of 24 cases (72%) and that for mPGES in tumor cells in 23 of 24 cases (92%). The localization of mPGES was very similar to that of COX-2. COX-2 in well-differentiated SCCs was higher than in poorly/moderately differentiated SCCs. In terms of lymph node metastasis, there was a significant difference in COX-2 expression.
Kawata
Ryo
R
Department of Otolaryngology, Osaka Medical College, Osaka, Japan. oto034@poh.osaka-med.ac.jp
Hyo
Sawako
S
Maeda
Tamaki
T
Urade
Yoshihiro
Y
Takenaka
Hiroshi
H
D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D019746:Intramolecular Oxidoreductases / Q000032:analysis*; D007822:Laryngeal Neoplasms / Q000473:pathology*; D007830:Larynx / Q000473:pathology; D054834:Lipocalins; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D000071876:Prostaglandin-E Synthases
D054834:Lipocalins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase; D000071876:Prostaglandin-E Synthases