This SuperSeries is composed of the SubSeries listed below.
Topoisomerase II inhibition involves characteristic chromosomal expression patterns.
Sex
View SamplesLung cancer is a leading cause of deaths in the world. There is a need to improve an understanding of mechanisms of malignant transformation and to develop genetic markers of disease for better and targeted therapies.
Cancer genomics identifies regulatory gene networks associated with the transition from dysplasia to advanced lung adenocarcinomas induced by c-Raf-1.
No sample metadata fields
View SamplesA variety of important anticancer drugs kill cells by increasing cellular levels of topoisomerase II-DNA cleavage complex. The anthracycline anticancer drug doxorubicin forms a stable ternary complex with DNA and topoisomerase IIa, thereby inhibiting the normal function of the enzyme.
Topoisomerase II inhibition involves characteristic chromosomal expression patterns.
Sex
View SamplesThe transcriptional regulator c-Myc is the most frequently deregulated oncogene in human tumors. Targeted overexpression of this gene in mice results in distinct types of lung adenocarcinomas. By using microarray technology, alterations in the expression of genes were captured based on a female transgenic mouse model in which, indeed, c-Myc overexpression in alveolar epithelium results in the development of bronchiolo-alveolar carcinoma (BAC) and papillary adenocarcinoma (PLAC).
Transcription profiling of lung adenocarcinomas of c-myc-transgenic mice: identification of the c-myc regulatory gene network.
No sample metadata fields
View SamplesTrovafloxacin is a broad spectrum antibiotic that inhibits the uncoiling of supercoiled DNA in various bacteria by blocking the activity of DNA gyrase and topoisomerase IV. Specific members of this drug family display high activity against eukaryotic type II topoisomerase, as well as cultured mammalian cells and in vivo tumor models. Trovafloxacin seems to have a higher affinity for eukaryotic polymerase II system than the other quinolone agents tested. This effect coupled with other factors, such as an inflammatory response, might result in a hepatotoxic reaction seen with drug.
Topoisomerase II inhibition involves characteristic chromosomal expression patterns.
Sex
View SamplesBackground: Information on the carcinogenic potential of chemicals is only availably for High Production Volume products. There is however, a pressing need for alternative methods allowing for the chronic toxicity of substances, including carcinogenicity, to be detected earlier and more reliably. Here we applied advanced genomics to a cellular transformation assay to identify gene signatures useful for the prediction of risk for carcinogenicity. Methods: Genome wide gene expression analysis and qRT-PCR were applied to untransformed and transformed Balb/c 3T3 cells that exposed to 2, 4-diaminotoluene (DAT), benzo(a)pyrene (BaP), 2-Acetylaminoflourene (AAF) and 3-methycholanthrene (MCA) for 24h and 120h, at different concentrations, respectively. Furthermore, various bioinformatics tools were used to identify gene signatures predicting for the carcinogenic risk. Results: Bioinformatics analysis revealed distinct datasets for the individual chemicals tested while the number of significantly regulated genes increased with ascending treatment concentration of the cell cultures. Filtering of the data revealed a common gene signature that comprised of 13 genes whose regulation in cancer tissue has already been established. Strikingly, this gene signature was already identified prior to cell transformation therefore confirming the predictive power of this gene signature in identifying carcinogenic risks of chemicals. Comparison of fold changes determined by microarray analysis and qRT-PCR were in good agreement. Conclusion: Our data describes selective and commonly regulated carcinogenic pathways observed in an easy to use in vitro carcinogenicity assay. Here we defined a set of genes which can serve as a simply assay to predict the risk for carcinogenicity by use of an alternative in vitro testing strategy.
Toxicogenomics applied to in vitro carcinogenicity testing with Balb/c 3T3 cells revealed a gene signature predictive of chemical carcinogens.
Cell line, Treatment, Time
View SamplesDiclofenac (DCL) is a non-steroidal anti-inflammatory drug. Its use can be associated with serious adverse drug reactions most notable myocardial infarction and drug-induced liver injury (DILI). The molecular causes leading to DILI remains unclear and it seems to be multifactorial. The aims of this study is to identify the molecular mechanisms involving immune mediated inflammatory reactions and its link to DILI through whole genome gene expression profiling. Diclofenac was given to mice at 30 mg/kg for 1, 3 and 14 days. Microarray experiments were performed with RNA extracts from liver samples. The performed gene expression studies showed >600 significantly regulated genes after single and repeated dosing for 3 and 14 days. The functional annotation revealed several genes were regulated in common coding for inflammatory, immune, stress and acute-phase responses. Immunohistochemistry, qRT-PCR as well as Western blotting were performed to evidence the regulation of key molecules in affected livers. In conclusion, the present study provides evidence for a mechanism of diclofenac induced liver injury that involves pro-inflammatory cytokine and acute phase responses.
Immunogenomics reveal molecular circuits of diclofenac induced liver injury in mice.
Treatment
View SamplesThe aim of reprotoxicity testing is to reveal adverse effects of chemicals and drugs on reproduction and on pre and postnatal fetal development. There is very limited data available on gene expression profiling for elucidation of the teratogenic effects of nongenotoxic teratogens. Therefore, research was undertaken to obtain knowledge on the molecular effects of MSC1096199 (previously known as EMD 82571), a calcium sensitizer that was abandoned in the preclinical development phase due to its teratogenic effects in some foetuses. Pregnant wistar rats were dose daily with either MSC1096199 (50 or 150 mg/kg) or Retinoic acid (12 mg/kg) on gestational days 6-17. Microarray experiment were performed using four different tissues (maternal liver, embryo liver (GD20), embryo bone (GD20), and whole embryo (GD12)) under four different conditions (vehicle, low dose and high dose of MSC1096199 and Retinoic acid) to determine the drug regulated genes. In the high dose treatment group, approximately 58% of the fetuses showed malformations i.e. exencephaly and agnathia, and toxicogenomics evidenced that the genes critically involved in osteogenesis, odontogenesis and extra cellular matrix components to be significantly regulated by MSC1096199, therefore providing a molecular rational for the observed teratogenic effects.
A rat toxicogenomics study with the calcium sensitizer EMD82571 reveals a pleiotropic cause of teratogenicity.
Specimen part, Treatment
View SamplesDevelopmental neurotoxicity (DNT) may be induced when chemicals disturb a key neurodevelopmental process, and many tests focus on this type of toxicity. Alternatively, DNT may occur when chemicals are cytotoxic only during a specific neurodevelopmental stage. The toxicant sensitivity is affected by the expression of toxicant targets and by resilience factors. Although cellular metabolism plays an important role, little is known how it changes during human neurogenesis, and how potential alterations affect toxicant sensitivity of mature vs. immature neurons. We used immature (d0) and mature (d6) LUHMES cells (dopaminergic human neurons) to provide initial answers to these questions. Transcriptome profiling and characterization of energy metabolism suggested a switch from predominantly glycolytic energy generation to a more pronounced contribution of the tricarboxylic acid cycle (TCA) during neuronal maturation. Therefore, we used pulsed stable isotope-resolved metabolomics (pSIRM) to determine intracellular metabolite pool sizes (concentrations), and isotopically non-stationary 13C-metabolic flux analysis (INST 13C MFA) to calculate metabolic fluxes. We found that d0 cells mainly use glutamine to fuel the TCA. Furthermore, they rely on extracellular pyruvate to allow continuous growth. This metabolic situation does not allow for mitochondrial or glycolytic spare capacity, i.e. the ability to adapt energy generation to altered needs. Accordingly, neuronal precursor cells displayed a higher sensitivity to several mitochondrial toxicants than mature neurons differentiated from them. In summary, this study shows that precursor cells lose their glutamine dependency during differentiation while they gain flexibility of energy generation and thereby increase their resistance to low concentrations of mitochondrial toxicants.
Stage-specific metabolic features of differentiating neurons: Implications for toxicant sensitivity.
Sex, Specimen part, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Nuclear ARRB1 induces pseudohypoxia and cellular metabolism reprogramming in prostate cancer.
Specimen part, Cell line
View Samples