Up-regulation of cyclooxygenase-1 and -2 in human gastric ulcer.
BACKGROUND
The expression of cyclooxygenase (COX) in human gastric ulcers is unknown.


OBJECTIVE
To study the expression and cellular localization of cyclooxygenase in human gastric ulcers.


METHODS
A total of 38 surgical gastric ulcer specimens were studied; 20 were Helicobacter pylori-positive and 18 were associated with NSAID use. Twenty non-ulcerated, histologically normal gastric specimens were used as controls. The cellular localization of COX-1 and COX-2 were determined by immunohistochemistry and double immunofluorescence. Cyclooxygenase messenger RNA (mRNA) was measured by reverse transcription-polymerase chain reaction and localized by in situ hybridization.


RESULTS
In control specimens, COX-1 was detected in stromal cells in the lamina propria. There was focal and weak immunostaining for COX-2 in the foveolar epithelium. At the ulcer edge, COX-1 was significantly increased in lamina propria cells whereas COX-2 was strongly expressed in the hyperplastic foveolar epithelium in H. pylori- and non-steroidal anti-inflammatory drugs (NSAID)-associated ulcers. At the ulcer base, there was strong expression of COX-1 and COX-2 in myofibroblasts, macrophages and endothelial cells in the granulation tissue, irrespective of H. pylori status or NSAID use. Messenger RNA of COX-1 and COX-2 were demonstrated by reverse transcription-polymerase chain reaction. Double immunofluorescence and in situ hybridization confirmed the cellular localization of cyclooxygenase at protein and mRNA levels, respectively.


CONCLUSIONS
Both COX-1 and COX-2 are up-regulated in human gastric ulcers.
To
K F
KF
Department of Anatomical & Cellular Pathology, The Chinese University of Hong Kong, Hong Kong.
Chan
F K
FK
Cheng
A S
AS
Lee
T L
TL
Ng
Y P
YP
Sung
J J
JJ
D000328:Adult; D000368:Aged; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D013276:Stomach Ulcer / Q000201:enzymology*; D015854:Up-Regulation
D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases