Expression of cyclooxygenase-1 and cyclooxygenase-2 in human esophageal mucosa, dysplasia and carcinoma.
OBJECTIVE
COX (cyclooxygenase), a prostaglandin H synthase, catalyzes the rate-limiting step in prostaglandin biosynthesis. Two isoforms of COX have been identified: COX-1 and COX-2. We examined the expression of COX-1 and COX-2 in esophageal normal mucosa, dysplasia and squamous cell carcinoma (SCC).


METHODS
The expression of COX-1 and COX-2 in 80 surgically removed esophagi due to SCC, as well as in 5 human esophageal SCC cell lines was analyzed, using immunohistochemistry and Western blot analyses.


RESULTS
COX-1 and COX-2 were variably expressed in the SCC cell lines. Higher COX-1 expression was noted in 31 (41.9%) of the 74 specimens of normal mucosa, in none of the 40 specimens of dysplastic mucosa and in 15 (18.8%) of the 80 specimens of SCC, the frequency being significantly higher in normal mucosa than in dysplasia or SCC (p < 0.0001, p = 0.0018, respectively). COX-1 expression was significantly higher in well-differentiated SCC than in moderately or poorly differentiated SCC (p < 0.01). Higher COX-2 expression was noted in none (0.0%) of the specimens of normal mucosa, in 12 (30%) of the specimens of dysplastic mucosa, and in 41 (51.3%) of the speciments of SCC, the frequency being significantly higher in SCC than in normal mucosa or dysplasia (p < 0.0001, p = 0.0278, respectively).


CONCLUSIONS
COX-1 is expressed in normal esophageal mucosa and is occasionally induced in well-differentiated SCC, whereas COX-2 expression is more characteristic of dysplasia and carcinoma than of normal mucosa, implying a possible association with cell differentiation in the former, and esophageal tumorigenesis in the latter.
Kase
Satoru
S
Division of Organ Pathology, Department of Microbiology and Pathology, Faculty of Medicine, Tottori University, Yonago, Japan.
Osaki
Mitsuhiko
M
Honjo
Soichiro
S
Hashimoto
Kiyoshi
K
Adachi
Hironobu
H
Tsujitani
Shunichi
S
Ito
Hisao
H
D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D004591:Electrophoresis, Polyacrylamide Gel; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000473:pathology; D004947:Esophagus / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis*; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D009092:Mucous Membrane / Q000378:metabolism* / Q000473:pathology; D009367:Neoplasm Staging; D011230:Precancerous Conditions / Q000378:metabolism* / Q000473:pathology; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis*
D014408:Biomarkers, Tumor; D007527:Isoenzymes; D008565:Membrane Proteins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases