Abstract
Nickel compounds may act as carcinogens, affecting both initiation and promotion stages of carcinogenesis due, in large parts, to their capability of inducing DNA damage and of modulating cellular signaling cascades known to affect cellular proliferation, respectively. We have previously demonstrated that the phosphoinositide 3-kinase (PI3K)/Akt signaling cascade is stimulated in cells exposed to copper ions, resulting in phosphorylation and nuclear exclusion of FoxO transcription factors. Here, human hepatoma cells were exposed to nickel or copper ions, followed by comparative analysis of PI3K/Akt-dependent signaling. Exposure of hepatoma cells to copper ions resulted in extensive oxidation of cellular glutathione, while no such effect was detected with nickel ions. Similarly, copper ions were more than 100-fold more toxic to cells than nickel, as deduced from analyses of colony forming abilities. Despite this lack of oxidative and cytotoxic action, exposure of hepatoma cells to Ni2+ resulted in a significant activation of Akt that was abrogated by inhibitors of PI3K. Interestingly, activation of Akt—although coincident with a phosphorylation of Akt substrates, such as glycogen synthase kinase-3—did not result in significant nuclear exclusion of FoxO1a. In line with this finding, no significant modulation of the activity of a FoxO-responsive promoter construct was observed in cells exposed to nickel ions. In summary, exposure of HepG2 human hepatoma cells to nickel ions results in stimulation of the Ser/Thr kinase Akt in a PI3K-dependent fashion, activation most likely being independent of oxidative processes. In sharp contrast to copper ions, nickel-induced Akt activation is not propagated further downstream to FoxO-dependent signaling beyond the phosphorylation of FoxO1a and 3a.
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References
Abdelmohsen K, Gerber PA, von Montfort C, Sies H, Klotz LO (2003) Epidermal growth factor receptor is a common mediator of quinone-induced signaling leading to phosphorylation of connexin-43: role of glutathione and tyrosine phosphatases. J Biol Chem 278:38360–38367. doi:10.1074/jbc.M306785200
Anderson ME (1985) Determination of glutathione and glutathione disulfide in biological samples. Methods Enzymol 113:548–555. doi:10.1016/S0076-6879(85)13073-9
Barthel A, Klotz LO (2005) Phosphoinositide 3-kinase signaling in the cellular response to oxidative stress. Biol Chem 386:207–216. doi:10.1515/BC.2005.026
Barthel A, Schmoll D, Krüger KD, Bahrenberg G, Walther R, Roth RA, Joost HG (2001) Differential regulation of endogenous glucose-6-phosphatase and phosphoenolpyruvate carboxykinase gene expression by the forkhead transcription factor FKHR in H4IIE-hepatoma cells. Biochem Biophys Res Commun 285:897–902. doi:10.1006/bbrc.2001.5261
Barthel A, Schmoll D, Unterman TG (2005) FoxO proteins in insulin action and metabolism. Trends Endocrinol Metab 16:183–189. doi:10.1016/j.tem.2005.03.010
Barthel A, Ostrakhovitch EA, Walter PL, Kampkötter A, Klotz LO (2007) Stimulation of phosphoinositide 3-kinase/Akt signaling by copper and zinc ions: mechanisms and consequences. Arch Biochem Biophys 463:175–182. doi:10.1016/j.abb.2007.04.015
Beyersmann D, Hartwig A (2008) Carcinogenic metal compounds: recent insight into molecular and cellular mechanisms. Arch Toxicol 82:493–512. doi:10.1007/s00204-008-0313-y
Costa M, Davidson TL, Chen H, Ke Q, Zhang P, Yan Y, Huang C, Kluz T (2005) Nickel carcinogenesis: epigenetics and hypoxia signaling. Mutat Res 592:79–88. doi:10.1016/j.mrfmmm.2005.06.008
Dally H, Hartwig A (1997) Induction and repair inhibition of oxidative DNA damage by nickel(II) and cadmium(II) in mammalian cells. Carcinogenesis 18:1021–1026. doi:10.1093/carcin/18.5.1021
Denkhaus E, Salnikow K (2002) Nickel essentiality, toxicity, and carcinogenicity. Crit Rev Oncol Hematol 42:35–56. doi:10.1016/S1040-8428(01)00214-1
Doble BW, Woodgett JR (2003) GSK-3: tricks of the trade for a multi-tasking kinase. J Cell Sci 116:1175–1186. doi:10.1242/jcs.00384
Gazel A, Rosdy M, Tornier C, De Fraissinette AD, Blumenberg M (2008) Transcriptional profiling defines the effects of nickel in human epidermal keratinocytes. J Cell Physiol 217:686–692. doi:10.1002/jcp21536
Goebeler M, Roth J, Brocker EB, Sorg C, Schulze-Osthoff K (1995) Activation of nuclear factor-kappa B and gene expression in human endothelial cells by the common haptens nickel and cobalt. J Immunol 155:2459–2467
Greer EL, Brunet A (2005) FOXO transcription factors at the interface between longevity and tumor suppression. Oncogene 24:7410–7425. doi:10.1038/sj.onc.1209086
Guo S, Rena G, Cichy S, He X, Cohen P, Unterman T (1999) Phosphorylation of serine 256 by protein kinase B disrupts transactivation by FKHR and mediates effects of insulin on insulin-like growth factor-binding protein-1 promoter activity through a conserved insulin response sequence. J Biol Chem 274:17184–17192. doi:10.1074/jbc.274.24.17184
Hartwig A, Asmuss M, Ehleben I, Herzer U, Kostelac D, Pelzer A, Schwerdtle T, Bürkle A (2002) Interference by toxic metal ions with DNA repair processes and cell cycle control: molecular mechanisms. Environ Health Perspect 110(Suppl 5):797–799
Kops GJ, Dansen TB, Polderman PE, Saarloos I, Wirtz KW, Coffer PJ, Huang TT, Bos JL, Medema RH, Burgering BM (2002) Forkhead transcription factor FOXO3a protects quiescent cells from oxidative stress. Nature 419:316–321. doi:10.1038/nature01036
Kortylewski M, Feld F, Krüger KD, Bahrenberg G, Roth RA, Joost HG, Heinrich PC, Behrmann I, Barthel A (2003) Akt modulates STAT3-mediated gene expression through a FKHR (FOXO1a)-dependent mechanism. J Biol Chem 278:5242–5249. doi:10.1074/jbc.M205403200
Li J, Davidson G, Huang Y, Jiang BH, Shi X, Costa M, Huang C (2004) Nickel compounds act through phosphatidylinositol-3-kinase/Akt-dependent, p70(S6k)-independent pathway to induce hypoxia inducible factor transactivation and Cap43 expression in mouse epidermal Cl41 cells. Cancer Res 64:94–101. doi:10.1158/0008-5472.CAN-03-0737
Maxwell P, Salnikow K (2004) HIF-1: an oxygen and metal responsive transcription factor. Cancer Biol Ther 3:29–35
Medema RH, Kops GJ, Bos JL, Burgering BM (2000) AFX-like Forkhead transcription factors mediate cell-cycle regulation by Ras and PKB through p27kip1. Nature 404:782–787. doi:10.1038/35008115
Nemoto S, Finkel T (2002) Redox regulation of forkhead proteins through a p66shc-dependent signaling pathway. Science 295:2450–2452. doi:10.1126/science.1069004
Ostrakhovitch EA, Cherian MG (2004) Differential regulation of signal transduction pathways in wild type and mutated p53 breast cancer epithelial cells by copper and zinc. Arch Biochem Biophys 423:351–361. doi:10.1016/j.abb.2004.01.004
Ostrakhovitch EA, Lordnejad MR, Schliess F, Sies H, Klotz LO (2002) Copper ions strongly activate the phosphoinositide-3-kinase/Akt pathway independent of the generation of reactive oxygen species. Arch Biochem Biophys 397:232–239. doi:10.1006/abbi.2001.2559
Schmoll D, Walker KS, Alessi DR, Grempler R, Burchell A, Guo S, Walther R, Unterman TG (2000) Regulation of glucose-6-phosphatase gene expression by protein kinase Balpha and the forkhead transcription factor FKHR. Evidence for insulin response unit-dependent and -independent effects of insulin on promoter activity. J Biol Chem 275:36324–36333. doi:10.1074/jbc.M003616200
Schwerdtle T, Hamann I, Jahnke G, Walter I, Richter C, Parsons JL, Dianov GL, Hartwig A (2007) Impact of copper on the induction and repair of oxidative DNA damage, poly(ADP-ribosyl)ation and PARP-1 activity. Mol Nutr Food Res 51:201–210. doi:10.1002/mnfr.200600107
Tran H, Brunet A, Grenier JM, Datta SR, Fornace AJ Jr, DiStefano PS, Chiang LW, Greenberg ME (2002) DNA repair pathway stimulated by the forkhead transcription factor FOXO3a through the Gadd45 protein. Science 296:530–534. doi:10.1126/science.1068712
Walter PL, Kampkötter A, Eckers A, Barthel A, Schmoll D, Sies H, Klotz LO (2006) Modulation of FoxO signaling in human hepatoma cells by exposure to copper or zinc ions. Arch Biochem Biophys 454:107–113. doi:10.1016/j.abb.2006.08.016
Walter PL, Steinbrenner H, Barthel A, Klotz LO (2008) Stimulation of selenoprotein P promoter activity in hepatoma cells by FoxO1a transcription factor. Biochem Biophys Res Commun 365:316–321
Zhang D, Li J, Wu K, Ouyang W, Ding J, Liu ZG, Costa M, Huang C (2007) JNK1, but not JNK2, is required for COX-2 induction by nickel compounds. Carcinogenesis 28:883–891. doi:10.1093/carcin/bgl186
Acknowledgments
This work is part of the PhD thesis of A.E. at the University of Düsseldorf. We thank Dr. A. Barthel, Bochum, and Dr. D. Schmoll, Frankfurt, for supplying FoxO antibodies and plasmids. Furthermore, we thank Dr. Gavin E. Arteel, University of Louisville, Dr. Niloofar Ale-Agha and Dr. Peter Schroeder (IUF, Düsseldorf) for helpful discussions. This study was supported by Deutsche Forschungsgemeinschaft (DFG, Bonn, Germany; SFB 728/B3 and GK1033).
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Eckers, A., Reimann, K. & Klotz, LO. Nickel and copper ion-induced stress signaling in human hepatoma cells: analysis of phosphoinositide 3′-kinase/Akt signaling. Biometals 22, 307–316 (2009). https://doi.org/10.1007/s10534-008-9167-2
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DOI: https://doi.org/10.1007/s10534-008-9167-2