Mountain View
biomedical and healthCAre Data Discovery Index Ecosystem
help Advanced Search
Title: Integration of metabolic activation with a predictive toxicogenomics signature to classify genotoxic versus nongenotoxic chemicals in human TK6 cells [S9]      
dateReleased:
05-14-2015
description:
The use of integrated approaches in genetic toxicology, including the incorporation of gene expression data to determine the molecular pathways involved in the response, is becoming more common. In a companion paper, a genomic biomarker was developed in human TK6 cells to classify chemicals as genotoxic or non-genotoxic. Because TK6 cells are not metabolically competent, we set out to broaden the utility of the biomarker for use with chemicals requiring metabolic activation. Specifically, chemical exposures were conducted in the presence of rat liver S9. The ability of the biomarker to classify genotoxic (benzo[a]pyrene, BaP; aflatoxin B1, AFB1) and non-genotoxic (dexamethasone, DEX; phenobarbital, PB) agents correctly was evaluated. Cells were exposed to increasing chemical concentrations for 4h and collected 0h, 4h and 20h post-exposure. Relative survival, apoptosis, and micronucleus frequency were measured at 24h. Transcriptome profiles were measured with Agilent microarrays. Statistical modeling and bioinformatics tools were applied to classify each chemical using the genomic biomarker. BaP and AFB1 were correctly classified as genotoxic at the mid- and high concentrations at all three time points, whereas DEX was correctly classified as non-genotoxic at all concentrations and time points. The high concentration of PB was misclassified at 24h, suggesting that cytotoxicity at later time points may cause misclassification. The data suggest that the use of S9 does not impair the ability of the biomarker to classify genotoxicity in TK6 cells. Finally, we demonstrate that the classifier is also able to accurately classify genotoxicity using a publicly available dataset derived from human HepaRG cells. This experiment examined the whole genome transcriptional response of TK6 cells exposed to 0.1 µM aflatoxin B1 (-S9), 10 µg/ml benzo[a]pyrene (-S9), 7.5 mM dexamethasone (-S9) and 24 µg/ml cisplatin (+S9) for 4 hours followed by a 0h, 4h and 20h recovery in fresh media (4h, 8h, and 24h time points, respectively), in addition to negative controls (±S9), vehicle controls (±S9), a direct-acting positive control, cisplatin (-S9) at 24 μg/ml and a positive control requiring metabolic activation, BaP (+S9) at 10 μg/ml. Each concentration and time point had 3 biological replicates, which were pooled for gene expression analysis. There were a total of 14 samples (28 arrays) included in the final analysis using a two-colour dye swap design.
privacy:
not applicable
aggregation:
instance of dataset
ID:
E-GEOD-68855
refinement:
raw
alternateIdentifiers:
68855
keywords:
functional genomics
dateModified:
05-22-2015
availability:
available
types:
gene expression
name:
Homo sapiens
ID:
A-GEOD-14550
name:
Agilent-028004 SurePrint G3 Human GE 8x60K Microarray (Probe Name Version)
accessURL: https://www.ebi.ac.uk/arrayexpress/files/E-GEOD-68855/E-GEOD-68855.raw.1.zip
storedIn:
ArrayExpress
qualifier:
gzip compressed
format:
TXT
accessType:
download
authentication:
none
authorization:
none
accessURL: https://www.ebi.ac.uk/arrayexpress/files/E-GEOD-68855/E-GEOD-68855.processed.1.zip
storedIn:
ArrayExpress
qualifier:
gzip compressed
format:
TXT
accessType:
download
authentication:
none
authorization:
none
accessURL: https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE68855
storedIn:
Gene Expression Omnibus
qualifier:
not compressed
format:
HTML
accessType:
landing page
primary:
true
authentication:
none
authorization:
none
abbreviation:
EBI
homePage: http://www.ebi.ac.uk/
ID:
SCR:004727
name:
European Bioinformatics Institute
homePage: https://www.ebi.ac.uk/arrayexpress/
ID:
SCR:002964
name:
ArrayExpress

Feedback?

If you are having problems using our tools, or if you would just like to send us some feedback, please post your questions on GitHub.