Role of cyclooxygenase-2 in colorectal cancer.
Cyclooxygenase-2 (COX-2) is an inducible enzyme that regulates prostaglandin synthesis and is overexpressed at sites of inflammation and in several epithelial cancers. Recently, a causal link for COX-2 in epithelial tumorigenesis was shown in genetically-manipulated animal models of colon and breast carcinoma. Data indicate that COX-2 is involved in the regulation of apoptosis, angiogenesis, and tumor cell invasiveness, which appear to contribute to its effects on tumorigenesis. Multiple studies have shown that nonselective COX and selective COX-2 inhibitors effectively prevent experimental colon cancer. Furthermore, sulindac and the selective COX-2 inhibitor celecoxib were shown to regress colorectal polyps in patients with familial adenomatous polyposis. Although the exact anti-tumor mechanisms of these agents await further study, data indicate that both COX-dependent and COX-independent mechanisms may be important. In this review, the association between COX-2 and colorectal tumorigenesis and potential mechanisms of this effect are discussed. Additionally, evidence supporting the role of NSAIDs and selective COX-2 inhibitors for the prevention and treatment of human colorectal cancer is reviewed.
Division of Gastroenterology and Hepatology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. sinicrope.frank@mayo.edu
Frank A
FA
Sinicrope
Sharlene
S
Gill
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D017209:Apoptosis; D015179:Colorectal Neoplasms / Q000378:metabolism*; D051546:Cyclooxygenase 2; D006801:Humans; D007527:Isoenzymes / Q000502:physiology*; D008565:Membrane Proteins; D008954:Models, Biological; D009361:Neoplasm Invasiveness; D009369:Neoplasms / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000502:physiology*; D011453:Prostaglandins / Q000378:metabolism
D000894:Anti-Inflammatory Agents, Non-Steroidal; D007527:Isoenzymes; D008565:Membrane Proteins; D011453:Prostaglandins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases