Expression of cyclooxygenase-2 protein in gastric adenocarcinoma.
OBJECTIVE
Epidemiological studies have suggested that the regular use of nonsteroidal antiinflammatory drugs, which inhibit cyclooxygenase (COX), reduces the risk of colon cancer. The inducible COX-2 isoform has been reported to be upregulated in colorectal carcinomas and may play a role in colorectal carcinogenesis. The purpose of this study was to investigate the expression of COX-2 protein in human gastric adenocarcinomas.


METHODS
COX-2 protein expression was examined in 23 patients with gastric adenocarcinoma by immunoblotting and immunohistochemistry.


RESULTS
There was an increase in COX-2 protein levels in 19 of the 23 carcinomas (83%) compared with the paired normal gastric mucosa by an immunoblot analysis. There was no correlation between tumor histology and COX-2 protein expression. An immunohistochemical study in the 19 cases showed diffuse COX-2 staining in the cytoplasm of cancer cells. Mononuclear cells or fibroblasts of the cancer stroma were not stained with COX-2. Sporadic staining for COX-2 was observed in the normal fundic or metaplastic glandular cells in all cases.


CONCLUSIONS
COX-2 protein expression was elevated in most human gastric adenocarcinomas in comparison to the normal mucosa. COX-2 may therefore play an important role in gastric carcinogenesis.
Uefuji
K
K
Department of Surgery I, National Defense Medical College, Tokorozawa, Japan.
Ichikura
T
T
Mochizuki
H
H
Shinomiya
N
N
D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology; D000328:Adult; D000368:Aged; D051546:Cyclooxygenase 2; D005260:Female; D005753:Gastric Mucosa / Q000201:enzymology; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism* / Q000502:physiology; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D010544:Peroxidases / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism* / Q000502:physiology; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000473:pathology
D007527:Isoenzymes; D008565:Membrane Proteins; D010544:Peroxidases; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases