[Arachidonic acid and prostaglandins, inflammation and oncology]. / Acide arachidonique et prostaglandines, inflammation et oncologie.

ABSTRACT

CYCLOOXYGENASE PATHWAY Among the 3 metabolic pathways leading to oxidation of arachidonic acid, the cyclooxygenase (COX) pathway produces prostaglandin G2 that is rapidly transformed into prostaglandin H2. PROSTAGLANDINS Prostaglandins are inflammation mediators that are strongly implicated in tumorgenesis. They participate in tumor initiation, promotion and growth. INFLAMMATION AND EPITHELIAL CANCER Chronic inflammation is a risk factor for epithelial cancer. It induces prostaglandin synthesis via activation of COX-2. There is a cause and effect relationship between chronic inflammation and carcinogeneis via COX-2 expression. It has been demonstrated that COX-2 favors tumor invasion and inhibits apoptosis. Tumor growth is favored by PGE2-induced reduction in immunity; COX-2 inhibitors reinforce the immune response. Finally COX-2 is expressed in tumor neovessels and plays a role in angiogenesis.