http://http://dspace.unitus.it:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. 2013-05-24T07:20:53Z http://hdl.handle.net/2067/2068 Title: Involvement of 5-lipoxygenase in survival of Epstein-Barr virus (EBV)-converted B lymphoma cells Authors: Belfiore, Maria Cristina; Natoni, Alessandro; Barzellotti, Roberta; Merendino, Nicolò; Pessina, Gloria; Gualandi, Giampiero Abstract: Epstein–Barr Virus (EBV) is involved in the progression of lymphomas through still unknown mechanism involving increased resistance to induced apoptosis. We show here that in a set of apoptosis-resistant EBV-converted Burkitt’s lymphoma clones, 5- and 12-lipoxygenases (LOXs) are over-expressed. Further investigations on 5-LOX showed that resistance to apoptosis increases parallely with the expression of 5-lipoxygenase (5-LOX). Inhibitors of 5-LOX: (a) decrease peroxides level, indicating that this enzyme promotes the generation of oxidative stress in EBV+ cells, and (b) potently induce apoptosis in the EBV resistant cell line E2R. 5- and 15-HETE, the products of the 5 and 15-LOXs, respectively, counteract 5-LOX inhibitor induced apoptosis, indicating that products of arachidonate metabolism, rather than peroxides, trigger a signal transduction that is required for survival of the EBV-converted cells. These findings suggest that 5- and, to a lesser extent, other LOXs, that are involved in tumor progression of several cell types, may also participate in lymphomagenesis, especially that EBV-mediated. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com 2006-12-31T23:00:00Z