Genes Encoding Enzymatic Activities Implicated in the Eicosanoid Cascade of Arachidonic Acid and their Receptors are Expressed at mRNA Levels in Human Meningiomas

In view of the important oncogenic action of lipoxygenase (LOX) and cycloxygenase (COX) enzymatic activities we investigated, by using real time PCR, their presence in human meningiomas. Results indicated the presence of 5-LOX, 12-LOX, 15-LOX1, 15-LOX2, COX-1, COX-2, prostaglandin E (PGE) synthase, prostacyclin (PGI) synthase and thromboxane (TX) synthase transcripts in meningiomas but without relation to the tumor grade, the subtype of meningiomas, the presence of inflammatory infiltrated cells, of an associated edema, mitosis, brain invasion, vascularisation or necrosis. Similar results were found for BLT1 and BLT2 transcripts (encoding LTB4 receptors) and for prostanoid receptor transcripts (EP1-4 for PGE2, IP for PGI2 and TP for TXA2). In conclusion, genes encoding enzymatic activities implicated in the eicosanoid cascade are expressed in meningiomas. LOX- and COX-derived arachidonic acid metabolites might act on tumor growth not only by acting on cell growth but also by altering the local cytokine and/ or angiogenic networks.