Cyclooxygenase‐2 modulates cellular growth and promotes tumorigenesis

Cyclooxygenase (COX)‐2 and the prostaglandins resulting from its enzymatic activity have been shown to play a role in modulating cell growth and development of human neoplasia. Evidence includes a direct relationship between COX‐2 expression and cancer incidence in humans and animal models, increased tumorigenesis after genetic manipulation of COX‐2, and significant anti‐tumor properties of non‐steroidal anti‐inflammatory drugs in animal models and in some human cancers. Recent data showed that COX‐2 and the derived prostaglandins are involved in control of cellular growth, apoptosis, and signal through a group of nuclear receptors named peroxisome proliferator‐activated receptors (PPARs). In this article we will review some of the findings suggesting that COX‐2 is involved in multiple cellular mechanisms that lead to tumorigenesis.