![]() |
|
|
Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL 32306-4340
3To whom correspondence should be addressed. E-mail: levenson{at}neuro.fsu.edu.
Copper toxicity causes hepatic damage that can lead to the development of hepatocarcinoma. Similarly, copper deficiency has been reported to increase hepatocyte tumorigenesis. Thus, the objective of this work was to explore the role of copper toxicity and deficiency in the regulation of the tumor suppressor protein p53. Using Northern analysis, Western analysis, immunocytochemistry and the human hepatoma cell line Hep G2, this work showed that elevations in hepatocyte copper consistent with Wilsons disease (5.7-fold increase) induced p53 mRNA and confirmed that copper toxicity is correlated with apoptotic cell death. However, Western analysis and immunocytochemistry showed that post-transcriptional mechanisms are a significant part of the process, with p53 translocation from the cytosol into the nucleus of copper-treated cells. Treatment of Hep G2 cells with increasing concentrations of the copper chelator tetraethylenepentamine (TEPA, 050 µmol/L, 48 h) reduced cellular copper and increased mean p53 mRNA abundance by over fourfold with nuclear translocation of the wild-type protein. However, TEPA treatment did not result in a loss of cell viability or appear to induce apoptosis.
KEY WORDS: p53 apoptosis Hep G2 liver
This article has been cited by other articles:
![]() |
L. Finney, S. Mandava, L. Ursos, W. Zhang, D. Rodi, S. Vogt, D. Legnini, J. Maser, F. Ikpatt, O. I. Olopade, et al. X-ray fluorescence microscopy reveals large-scale relocalization and extracellular translocation of cellular copper during angiogenesis PNAS, February 13, 2007; 104(7): 2247 - 2252. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. L. Caruano-Yzermans, T. B. Bartnikas, and J. D. Gitlin Mechanisms of the Copper-dependent Turnover of the Copper Chaperone for Superoxide Dismutase J. Biol. Chem., May 12, 2006; 281(19): 13581 - 13587. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. M. Tassabehji, J. W. VanLandingham, and C. W. Levenson Copper Alters the Conformation and Transcriptional Activity of the Tumor Suppressor Protein p53 in Human Hep G2 Cells Experimental Biology and Medicine, November 1, 2005; 230(10): 699 - 708. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. E. Hellman, S. Kono, G. M. Mancini, A. J. Hoogeboom, G. J. de Jong, and J. D. Gitlin Mechanisms of Copper Incorporation into Human Ceruloplasmin J. Biol. Chem., November 22, 2002; 277(48): 46632 - 46638. [Abstract] [Full Text] [PDF] |
||||