ToxSci Advance Access first published online on May 11, 2005
This version published online on May 25, 2005
Toxicological Sciences, doi:10.1093/toxsci/kfi192
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1 Laboratoire de Toxicologie Cellulaire et Moléculaire, Centre de Recherche INRA, 400 route des Chappes, 06903 Sophia-Antipolis, France
* To whom correspondence should be addressed. Organochlorine pesticides (OCs) are reported as potential carcinogens in humans. The aim of this study was to investigate the effects of four OCs (dieldrin, endosulfan, heptachlor and lindane) on MAPK cascades and more specifically to identify the mechanism underlying OCs-induced ERK1/2 activation. OCs increased phosphorylated Raf, MEK1/2, ERK1/2 and c-Jun in human HaCaT cells, but had no effect on p38 MAPK activation. Moreover, blockade of Raf, MEK1/2 or PKC activation with geldanamycin, U0126 or calphostin C inhibited ERK1/2 phosphorylation, demonstrating a PKC-Raf-MEK1/2 pathway. We also showed that these insecticides induced the production of reactive oxygen species (ROS). Pre-treatment with antioxidant molecule N-acetyl cysteine sharply decreased the level of phospho-ERK1/2, and had no effect on Raf and MEK1/2 activation, suggesting a Rafindependent mechanism. This study indicates that OCs strongly activate the ERK1/2 pathway, and identifies a critical role of ROS in OCs-induced ERK activation probably by stabilizing its phosphorylation. The author names are correct in this version.
Received March 7, 2005
Accepted April 28, 2005
Systems Toxicology
Effects of organochlorine insecticides on MAP kinase pathways in human HaCaT keratinocytes : Key role of reactive oxygen species
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2 Galderma R&D, les Templiers, 2400 routes des Colles, 06410 Biot, France
Nathalie Ledirac, E-mail: ledirac{at}antibes.inra.fr
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Abstract
These authors have equally contributed to the work.![]()
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