Endosulfan decreases cell growth and apoptosis in human HaCaT keratinocytes: Partial ROS-dependent ERK1/2 mechanism
Article first published online: 14 MAY 2007
Copyright © 2007 Wiley-Liss, Inc.
Journal of Cellular Physiology
Volume 213, Issue 1, pages 177–186, October 2007
How to Cite
Antherieu, S., Ledirac, N., Luzy, A.-P., Lenormand, P., Caron, J.-C. and Rahmani, R. (2007), Endosulfan decreases cell growth and apoptosis in human HaCaT keratinocytes: Partial ROS-dependent ERK1/2 mechanism. J. Cell. Physiol., 213: 177–186. doi: 10.1002/jcp.21108
- Issue published online: 19 JUL 2007
- Article first published online: 14 MAY 2007
- Manuscript Accepted: 13 MAR 2007
- Manuscript Received: 13 OCT 2006
- The Région Provence-Alpes-Côte d'Azur
- Galderma R&D
Endosulfan is an organochlorine insecticide described as a potential carcinogen in humans. This insecticide was recently reported to alter the mitogen-activated protein (MAP) kinase signaling pathways and is suspected to affect cell growth and differentiation in human keratinocytes. This study was designed to assess the mitogenic, apoptogenic, and genotoxic effects of endosulfan on the HaCaT cell line. We first found that 25 µM endosulfan led to persistent extracellular signal-regulated kinase (ERK)1/2 phosphorylation with an accumulation of the phosphorylated form in the nucleus, probably caused by MAP kinase phosphatase (MKP) inhibition. As previously described under sustained ERK1/2 activation, cell growth was decreased: delayed confluency and 35% decrease of BrdU incorporation was demonstrated in endosulfan-treated keratinocytes. In addition, endosulfan has been shown to generate transient reactive oxygen species (ROS), and blocking this oxidative stress by N-acetyl cysteine (NAC) strongly prevented both persistent nuclear ERK1/2 phosphorylation and cell growth decrease. Additional experiments demonstrated that unchanged endosulfan rather than its metabolites has mutagenic effects (Ames positive without S9) and increased DNA strand breaks (Comet assay) in HaCaT cells, via a ROS-dependent mechanism. Therefore, to assess the putative pro-apoptotic response of damaged cells, caspases 3/7 activity and poly(ADP-ribose)-polymerase (PARP) cleavage were measured. The results clearly indicated that endosulfan inhibited both spontaneous and staurosporine-induced apoptosis. Taken together, these findings strongly support that endosulfan induces ROS generation leading to sustained ERK1/2 phosphorylation and decrease in cell growth. Moreover, endosulfan was found to inhibit apoptosis and this could contribute to mutant cell survival and therefore have possible carcinogenic effects. J. Cell. Physiol. 213: 177–186, 2007. © 2007 Wiley-Liss, Inc.