Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA124507 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description: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 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.
2010-05-28 | E-GEOD-20993 | biostudies-arrayexpress
Project description: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
2010-04-29 | GSE20993 | GEO
Project description:N-nitroso compounds (NOC) are genotoxic compounds and animal carcinogens, and may play a role in human cancer development. Since the gastro-intestinal tract is an important route of exposure, we hypothesize that NOC exposure targets genetic processes relevant in colon carcinogenesis. To investigate this, we analysed the transcriptomic effects of genotoxic concentrations of two nitrosamides, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG, 1µM) and N-methyl-N-nitrosurea (MNU, 1mM), and four nitrosamines, N-nitrosodiethylamine (NDEA, 50mM), N-nitrosodimethylamine (NDMA, 100mM), N-nitrosopiperidine (NPIP, 40mM), and N-nitrosopyrrolidine (NPYR, 100mM), in the human colon carcinoma cell line Caco-2. Gene Ontology gene group, consensus motif gene group and biological pathway analysis revealed that nitrosamides had little effect on gene expression after 24 hours of exposure, whereas nitrosamines had a strong impact on the transcriptomic profile. Analyses showed modifications of cell cycle regulation and apoptosis pathways for nitrosamines which was supported by flow cytometric analysis. We found additional modifications in gene groups and pathways of oxidative stress and inflammation, which suggest an increase in oxidative stress and pro-inflammatory immune response upon nitrosamine exposure, although less distinct for NDMA. Furthermore, NDEA, NPIP and NPYR most strongly affected several developmental motif gene groups and pathways, which may influence developmental processes. Many of these pathways and gene groups are implicated in the carcinogenic process and their modulation by nitrosamine exposure may therefore influence the development of colon cancer. In summary, our study has identified pathway modifications in human colon cells which may be associated with cancer risk of nitrosamine exposure in the human colon. Keywords: Comparison of genome-wide gene expression between different conditions The study investigated differential gene expression in Caco-2 cell line mRNA following 24 hours of exposure to six different N-nitroso compounds. Four biological replicates per sample compound. One compound per array, hybridized against vehicle control. Dye-swap between biological replicates 1 and 2, and 3 and 4.
2010-04-03 | E-GEOD-14284 | biostudies-arrayexpress
Project description:Study hypothesis: We hypothesise that both colon inflammation and a diet high in red meat increase the endogenous formation of potentially carcinogenic N-nitroso compounds in the human colon and that these compounds increase the colorectal cancer risk, which could (partially) explain the increased colorectal cancer risk that is associated with inflammatory bowel disease and diets high in red meat.
Inflammatory bowel disease is characterised by a chronic inflammation within the gastrointestinal tract, which, in case of ulcerative colitis, is present in the colon and rectum.
Primary outcome(s): 1. Whole genome gene expression modifications by microarray analysis (4x44K Agilent platform)
2. Apparent total nitroso compounds in faecal matter by thermal energy analysis
3. Faecal water genotoxicity (30 minute exposure to 10% faecal water) by comet assay analysis in the adenocarcinoma cell line Caco-2
All outcomes are measured at baseline and post intervention.
| 2415737 | ecrin-mdr-crc
Project description:Molecular signatures of N-nitroso compounds in Caco-2 cells: implications for colon carcinogenesis
| PRJNA111277 | ENA
Project description:The mode of action of silver nanoparticles (AgNPs) is suggested to be exerted through both Ag+ and AgNP dependent mechanisms. Ingestion is one of the major NP exposure routes, and potential effects are often studied using Caco-2 cells, a well-established model for the gut epithelium. MCF-7 cells are epithelial breast cancer cells with extensive well-characterized toxicogenomics profiles. In the present study we aimed to gain a deeper understanding of the cellular molecular responses in Caco-2 and MCF-7 cells after AgNP exposure in order to evaluate whether epithelial cells derived from different tissues demonstrated similar responses. These insights could possibly reduce the size of cell panels for NP hazard identification screening purposes. AgNPs of 20, 30, 60, and 110 nm, and AgNO3 were exposed for 6h and 24h. AgNPs were shown to be taken up and dissolve intracellularly. Compared with MCF-7 cells, Caco-2 cells showed a higher sensitivity to AgNPs, slower gene expression kinetics, and absence of NP size-dependent responses. However, on a molecular level, no significant differences were observed between the two cell types. Transcriptomic analysis showed that Ag(NP) exposure caused (oxidative) stress responses, possibly leading to cell death in both cell lines. There was no indication for effects specifically induced by AgNPs. Responses to AgNPs appeared to be induced by silver ions released from the AgNPs. In conclusion, differences in mRNA responses to AgNPs between Caco-2 and MCF-7 cells were mainly related to timing and magnitude, but not to a different underlying mechanism.
2016-07-30 | GSE84982 | GEO
Project description:DrugMatrix is a comprehensive rat toxicogenomics database and analysis tool developed to facilitate the integration of toxicogenomics into hazard assessment. Using the whole genome and a diverse set of compounds allows a comprehensive view of most pharmacological and toxicological questions and is applicable to other situations such as disease and development. Complete Drug Matrix dataset for rat kidney. Approximately 600 different compounds were profiled in up to 7 different rat tissues by obtaining tissue samples from test compound-treated and vehicle control-treated rats in biological triplicates for gene expression analysis after 0.25, 1, 3, and 5 days of exposure with daily dosing. In a few studies (1.8%), 7 days of exposure was substituted for 5 days of exposure. Samples were hybridized to whole genome RG230_2.0 rat GeneChip (Affymetrix, CA).
2014-05-27 | E-GEOD-57811 | biostudies-arrayexpress
Project description:DrugMatrix is a comprehensive rat toxicogenomics database and analysis tool developed to facilitate the integration of toxicogenomics into hazard assessment. Using the whole genome and a diverse set of compounds allows a comprehensive view of most pharmacological and toxicological questions and is applicable to other situations such as disease and development. Complete Drug Matrix dataset for rat liver. Approximately 600 different compounds were profiled in up to 7 different rat tissues by obtaining tissue samples from test compound-treated and vehicle control-treated rats in biological triplicates for gene expression analysis after 00.25, 1, 3, and 5 days of exposure with daily dosing. In a few studies (1.8%), 7 days of exposure was substituted for 5 days of exposure. Samples were hybridized to whole genome RG230_2.0 rat GeneChip arrays (Affymetrix, CA).
2014-05-27 | E-GEOD-57815 | biostudies-arrayexpress
Project description:DrugMatrix is a comprehensive rat toxicogenomics database and analysis tool developed to facilitate the integration of toxicogenomics into hazard assessment. Using the whole genome and a diverse set of compounds allows a comprehensive view of most pharmacological and toxicological questions and is applicable to other situations such as disease and development. Complete Drug Matrix dataset for rat bone marrow. Approximately 600 different compounds were profiled in up to 8 different rat tissues by obtaining tissue samples from test compound-treated and vehicle control-treated rats in biological triplicates for gene expression analysis after 0.25, 1, 3, and 5 days of exposure with daily dosing. In a few studies (1.8%), 7 days of exposure was substituted for 5 days of exposure. Samples were hybridized to CodeLink RU1 10K rat arrays (Amersham Biosciences).
2014-08-18 | E-GEOD-59894 | biostudies-arrayexpress
Project description:DrugMatrix is a comprehensive rat toxicogenomics database and analysis tool developed to facilitate the integration of toxicogenomics into hazard assessment. Using the whole genome and a diverse set of compounds allows a comprehensive view of most pharmacological and toxicological questions and is applicable to other situations such as disease and development. Complete Drug Matrix dataset for rat brain. Approximately 600 different compounds were profiled in up to 8 different rat tissues by obtaining tissue samples from test compound-treated and vehicle control-treated rats in biological triplicates for gene expression analysis after 0.25, 1, 3, and 5 days of exposure with daily dosing. In a few studies (1.8%), 7 days of exposure was substituted for 5 days of exposure. Samples were hybridized to CodeLink RU1 10K rat arrays (Amersham Biosciences).
2014-08-18 | E-GEOD-59895 | biostudies-arrayexpress