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HaRas activates the NADPH oxidase complex in human neuroblastoma cells via extracellular signal‐regulated kinase 1/2 pathway
Author(s) -
Serù Rosalba,
Mondola Paolo,
Damiano Simona,
Svegliati Silvia,
Agnese Savina,
Avvedimento Enrico V.,
Santillo Mariarosaria
Publication year - 2004
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2004.02754.x
Subject(s) - nadph oxidase , wortmannin , superoxide , microbiology and biotechnology , reactive oxygen species , kinase , ly294002 , staurosporine , chemistry , signal transduction , protein kinase a , biology , pi3k/akt/mtor pathway , biochemistry , enzyme
In this study we have investigated the effects of the small GTP‐binding‐protein Ras on the redox signalling of the human neuroblastoma cell line, SK‐N‐BE stably transfected with HaRas(Val12). The levels of reactive oxygen species (ROS) and superoxide anions were significantly higher in HaRas(Val12) expressing (SK‐HaRas) cells than in control cells. The treatment of cells with 4‐(2‐aminoethyl) benzenesulfonylfluoride, a specific inhibitor of the membrane superoxide generating system NADPH oxidase, suppressed the rise in ROS and significantly reduced superoxide levels produced by SK‐HaRas cells. Moreover, HaRas(Val12) induced the translocation of the cytosolic components of the NADPH oxidase complex p67 phox and Rac to the plasma membrane. These effects depended on the mitogen‐activated protein kinase kinase/extracellular signal‐regulated kinase (MEK/ERK1/2) pathway, as the specific MEK inhibitor, PD98059, prevented HaRas‐mediated increase in ROS and superoxide anions. In contrast, the specific phosphoinositide 3‐kinase (PI3K) inhibitors LY294002 and wortmannin were unable to reverse the effects of HaRas(Val12). Moreover, cholinergic stimulation of neuroblastoma cells by carbachol, which activated endogenous Ras/ERK1/2, induced a significant increase in ROS levels and elicited membrane translocation of p67 phox and Rac. ROS generation induced by carbachol required the activation of ERK1/2 and PI3K. Hence, these data indicate that HaRas‐induced ERK1/2 signalling selectively activates NADPH oxidase system in neuroblastoma cells.