PT  - JOURNAL ARTICLE
AU  - Ellen Fritsche
AU  - Seung Joon Baek
AU  - Lorraine M. King
AU  - Darryl C. Zeldin
AU  - Thomas E. Eling
AU  - Douglas A. Bell
TI  - Functional Characterization of Cyclooxygenase-2 Polymorphisms
DP  - 2001 Nov 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 468--476
VI  - 299
IP  - 2
4099  - http://jpet.aspetjournals.org/content/299/2/468.short
4100  - http://jpet.aspetjournals.org/content/299/2/468.full
SO  - J Pharmacol Exp Ther2001 Nov 01; 299
AB  - Cyclooxygenases (COX)-1 and -2 are the key enzymes in the conversion of arachidonic acid to prostaglandins. COX-2 appears to play an emerging role in inflammation and carcinogenesis. Nonsteroidal anti-inflammatory drugs (NSAIDs) are used for the treatment of numerous diseases and reduce the risk of developing colorectal cancer. Polymorphisms in the COX-2 gene could alter enzyme expression, function, and/or the response to NSAIDs. Therefore, they could modify individual risks for developing cancer and other diseases or the occurrence of side effects or sensitivity toward selective or nonselective COX inhibitors. We sequenced the COX-2 gene of 72 individuals and identified rare polymorphisms in the promoter and the coding region. A COX-2 molecular model was used to locate the coding region polymorphisms relative to functional sites in the protein, and the COX-2 V511A polymorphism was very near to the active site. This variant protein was expressed, and function was evaluated, but no difference was detected in metabolism of the COX-2 substrates, arachidonic acid, linoleic acid, and 2-arachidonyl glycerol, compared with the wild type. TheKm values for arachidonic acid showed no differences between the COX-2 wild type and V511A mutant. Inhibition with selective or nonselective COX inhibitors was essentially the same for the two enzymes. The absence of functionally important polymorphisms in the COX-2 gene may suggest that there has been selective pressure against those single nucleotide polymorphisms because of the critical role of this enzyme in maintenance of homeostasis. U.S. Government