This SuperSeries is composed of the SubSeries listed below.
Dynamic changes in 5-hydroxymethylation signatures underpin early and late events in drug exposed liver.
Sex, Specimen part, Treatment, Time
View Samples29-32 days old male mice where either treated with Phenobarbital or untreated
Dynamic changes in 5-hydroxymethylation signatures underpin early and late events in drug exposed liver.
Sex, Specimen part, Treatment, Time
View SamplesAcute effects caused by the non-genotoxic carcinogen and peroxisome proliferator (PP) diethylhexylphthalate (DEHP) in the mouse liver
Gene ontology mapping as an unbiased method for identifying molecular pathways and processes affected by toxicant exposure: application to acute effects caused by the rodent non-genotoxic carcinogen diethylhexylphthalate.
Sex, Specimen part, Compound, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sex, Age, Specimen part, Treatment, Subject, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sex, Specimen part, Treatment, Subject
View SamplesEvidence suggests that epigenetic perturbations are involved in the adverse effects associated with some drugs and toxicants, including certain classes of non-genotoxic carcinogens. Such epigenetic changes (altered DNA methylation and covalent histone modifications) may take place at the earliest stages of carcinogenesis and their identification holds great promise for biomedical research. Here, we evaluate the sensitivity and specificity of genome-wide epigenomic and transcriptomic profiling in phenobarbital (PB)-treated B6C3F1 mice, a well-characterized rodent model of non-genotoxic liver carcinogenesis. Methylated DNA Immunoprecipitation (MeDIP)-coupled microarray profiling of 17,967 promoter regions and 4,566 intergenic CpG islands was combined with genome-wide mRNA expression profiling to identify liver tissue-specific PB-mediated DNA methylation and transcriptional alterations. Only a limited number of significant anti-correlations were observed between PB-induced transcriptional and promoter-based DNA methylation perturbations. However, the constitutive androstane receptor (CAR) target gene Cyp2b10 was found to be concomitantly hypomethylated and transcriptionally activated in a liver tissue-specific manner following PB treatment. Furthermore, analysis of active and repressive histone modifications using chromatin immunoprecipitation revealed a strong PB-mediated epigenetic switch at the Cyp2b10 promoter. Our data reveal that PB-induced transcriptional perturbations are not generally associated with broad changes in the DNA methylation status at proximal promoters and suggest that the drug-inducible CAR pathway regulates an epigenetic switch from repressive to active chromatin at the target gene Cyp2b10. This study demonstrates the utility of integrated epigenomic and transcriptomic profiling for elucidating early mechanisms and biomarkers of non-genotoxic carcinogenesis.
Phenobarbital mediates an epigenetic switch at the constitutive androstane receptor (CAR) target gene Cyp2b10 in the liver of B6C3F1 mice.
Sex, Specimen part, Treatment, Subject
View SamplesThe process of hepatocarcinogenesis in the diethylnitrosamine (DEN) initiation/phenobarbital (PB) promotion mouse model involves the selective clonal outgrowth of cells harboring oncogene mutations in Ha-ras, B-raf, or Ctnnb1. Here, we have characterized mouse liver tumors harboring either Ctnnb1 or Ha-ras mutations via integrated molecular profiling at the transcriptional and translational and post-translational levels. In addition, metabolites of the intermediary metabolism were quantified by high resultion 1H magic angle nuclear magnetic resonance (HR-MAS NMR). We have identified tumor characteristic genotype-specific differences in mRNA and miRNA expression, protein levels, and post-translational modifications and in metabolite levels that facilitate the molecular and biochemical stratification of tumor phenotypes. Bioinformatic integration of these data at the pathway level led to novel insights into tumor genotype-specific aberrant cell signaling and in particular to a better understanding of alterations in pathways of the cell intermediary metabolism, which are driven by the constitutive activation of the -Catenin and Ha-ras oncoproteins in tumors of the two genotypes.
Ha-ras and β-catenin oncoproteins orchestrate metabolic programs in mouse liver tumors.
Sex, Specimen part
View Samples