The Cyclooxygenase-2 Essay -- Health, Diseases

The cyclooxygenase-2 (cyclooxygenase-2) is a key enzyme in the conversion of arachidonic acid to prostaglandins, which promote cellular telephone proliferation, angiogenesis and metastasis, and inhibit apoptosis. Un resembling COX-1, which is constitutively expressed isoform, COX-2 is an inducible isoform of cyclooxygenase and which may record in inflammatory responses and contribute to inflammation and cancersthe development of colorectal cancer as well as other human cancers (1). COX-2 is not detectable detected in most normal tissues. However, it but is promptly induced when stimulated by in response to mitogens, cytokines and tumor promoters, which leads to the star(p) to increased accumulation of prostanoids in neoplastic and inflamed tissues (2). COX-2 is extremely expressed at high levels in intestinal tumors in rodents and earth (1). For example, Mmore than 80% of tout ensemble colorectal tumors were shown to overexpress COX-2 (3-5). Epidemiologic studies reserve sh own that winning aspirin or other nonsteroidal anti-inflammatory drugs on a regular basis could reduce mortality from colorectal cancer by 40-50% compared with those who not taking these drugs (1). One characteristic shared by all of these drugs is their ability to inhibit COX natural action and/or expression (1).Although COX-2 is expressed in 80-90% of human colon carcinoma specimens, not all colorectal cancer cell lines constitutively expressed COX-2. Constitutive expression of COX-2 was besides detected in a relatively small number of effected colorectal carcinoma cell lines (6). For example, human colon adenocarcinoma cell lines, HCT116 and SW480, wipe out been described as COX-2 negative, since they did not express COX-2, neither at mRNA nor at protein level (7). COX-2-derived prostaglandin E2 (PGE2) ... ...t as well as when the learned medium will be collected, with multiple parameters in which not provided COX-2 mRNA and protein as well as PGE2 levels will be observed , but also other relevant molecular markers or factors like those mentioned above.Not only paradoxical observations of COX-2 expression and the functional activity in human colon cancer cell line have been documented, the role of PGE2 on inflammation seems also paradoxical. Although PGE2 is a potent intermediary of inflammation (55), it was suggested that PGE2, endogenous COX products, also inhibit acute sensitized inflammation (56). Thus, PGE2 may produce both pro- and anti-inflammatory effects (57). to a greater extent extensive well-designed experiments are needed to help us to unveil the mystery of COX-2 expression and the functional activity as well as their roles in physiological and pathophysiological conditions.