Abstract
Epidemiological studies suggest that the use of aspirin decreases the incidence of and mortality from gastrointestinal cancers. The best known target of aspirin and other nonsteroidal anti-inflammatory drugs is cy-clooxygenase (Cox), the rate-limiting enzyme in the conversion of arachidonic acid to prostanoids. Two Cox genes have been cloned, of which Cox-2 is an inducible immediate-early gene. It is still unknown how nonsteroidal anti-inflammatory drugs act as chemopreventive agents, but they may target Cox-2. Cox-2 mRNA and protein were recently found to be expressed in human colon carcinoma. We have now studied the expression of Cox-2 in human gastric adenocarcinoma tissues which contained significantly higher levels of Cox-2 mRNA when compared with paired gastric mucosal specimens devoid of cancer cells. In contrast, Cox-1 mRNA levels were not elevated in the carcinoma. However, Cox-2 mRNA was not expressed in mucinous ovarian carcinoma samples as detected by Northern blot hybridization. Immunohistological detection of Cox-2 protein showed cytoplasmic staining in the gastric carcinoma cells but not in the surrounding stroma. Some hyperplastic glands showed intense staining, whereas glands of normal morphology were negative. Our data thus suggest that Cox-2 is expressed by human gastric adenocarcinoma.
Footnotes
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↵1 Supported by the Academy of Finland and Helsinki University Central Hospital Research Funds.
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↵2 To whom requests for reprints should be addressed, at Research Laboratory, Department of Obstetrics and Gynecology, Haartman Institute, University of Helsinki, Haartmaninkatu 2, SF-00290 Helsinki, Finland. Phone: 358-9-471-4981; Fax: 358-9-471-4801.
- Received November 5, 1996.
- Accepted February 8, 1997.
- ©1997 American Association for Cancer Research.
Volume 57, Issue 7
