Biological functions of cyclooxygenase 2: control of its expression and activity

Cyclooxygenase (COX) plays a pivotal role in the biosynthesis of prostanoids. The identification of an inducible isoform, COX-2, besides the constitutive one, COX-1, suggested that the latter was dedicated to cytoprotection, whereas the former was responsible for inflammation and neoplasia. This oversimplification was amended due to the synthesis of new selective inhibitors of COX-2 and to the deletion of the COX-2 gene, which demonstrated the involvement of the inducible isoform in physiological as well as in pathological functions. Moreover, several reports describe effects of nonsteroidal anti-inflammatory drugs which do not result from the inhibition of COX activity.