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| Status |
Public on Apr 29, 2010 |
| Title |
Time-series toxicogenomics analysis of N-nitroso compound exposure in Caco-2 cells |
| Organism |
Homo sapiens |
| Experiment type |
Expression profiling by array
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| Summary |
N-nitroso compounds (NOC) may be implicated in human colon carcinogenesis, but the toxicological mechanisms involved have not been elucidated. Since it was previously demonstrated that nitrosamines and nitrosamides, representing two classes of NOC, induce distinct gene expression effects in colon cells that are particularly related to oxidative stress, we hypothesized that different radical mechanisms are involved. Using ESR spectroscopy, we investigated radical generating properties of genotoxic NOC concentrations in human colon adenocarcinoma cells (Caco-2). Cells were exposed to nitrosamides (N-methyl-N'-nitro-N-nitrosoguanidine, N-methyl-N-nitrosurea) or nitrosamines (N-nitrosodiethylamine, N-nitrosodimethylamine, N-nitrosopiperidine, N-nitrosopyrrolidine). Nitrosamines caused formation of reactive oxygen species (ROS) and carbon centered radicals which was further stimulated in presence of Caco-2 cells. N-methyl-N-nitrosurea exposure resulted in a small ROS signal, and formation of nitrogen centered radicals (NCR), also stimulated by Caco-2 cells. N-methyl-N'-nitro-N-nitrosoguanidine did not cause radical formation at genotoxic concentrations, but at increased exposure levels, both ROS and NCR formation was observed. By associating gene expression patterns with ROS formation, several cellular processes responding to nitrosamine exposure were identified, including apoptosis, cell cycle blockage, DNA repair and oxidative stress. These findings suggest that following NOC exposure in Caco-2 cells, ROS formation plays an important role in deregulation of gene expression patterns which may be relevant for the process of chemical carcinogenesis in the human colon, in addition to the role of DNA alkylation.
Keywords: Nitrosamines, nitrosamides, N-nitroso compounds, free radicals, toxicogenomics, colon carcinogenesis
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| Overall design |
The study investigated differential gene expression in Caco-2 cell line mRNA following 1, 6 or 24 hours of exposure to six different N-nitroso compounds. Two biological replicates per sample compound. One compound per array, hybridized against vehicle control. Dye-swap between biological replicates.
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| Contributor(s) |
Hebels DG, Briedé JJ, Kleinjans JC, de Kok TM |
| Citation(s) |
20403970 |
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| Submission date |
Mar 22, 2010 |
| Last update date |
Feb 22, 2018 |
| Contact name |
Dennie Hebels |
| E-mail(s) |
d.hebels@maastrichtuniversity.nl
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| Phone |
0031-43-3881088
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| Fax |
0031-43-3884146
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| URL |
http://www.grat.nl
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| Organization name |
Maastricht University
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| Department |
Health Risk Analysis and Toxicology
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| Street address |
Universiteitssingel 50
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| City |
Maastricht |
| ZIP/Postal code |
6200MD |
| Country |
Netherlands |
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| Platforms (1) |
| GPL4133 |
Agilent-014850 Whole Human Genome Microarray 4x44K G4112F (Feature Number version) |
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| Samples (36)
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| Relations |
| BioProject |
PRJNA124507 |
| Supplementary file |
Size |
Download |
File type/resource |
| GSE20993_RAW.tar |
226.9 Mb |
(http)(custom) |
TAR (of GPR) |
| Processed data included within Sample table |
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