The Keap1/Nrf2 signaling pathway is a tractable target for the pharmacological prevention of tumorigenesis. 3H-1,2-dithiole-3-thione (D3T) and 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im) are representative members of two classes of Nrf2-activating chemopreventive agents. Natural dithiolethiones have been widely used in clinical trials for cancer chemoprevention. Synthetic triterpenoids, however, have been shown to be significantly more potent Nrf2 activators and are under clinical evaluation for the treatment of chronic kidney disease. This study seeks to characterize the structure-activity relationship between D3T and CDDO-Im in mouse liver tissue. To this end we treated Wt and Nrf2-null mice with 300 umol/kg bw D3T and 3, 10, and 30 umol/kg bw CDDO-Im every other day for 5 days and evaulated global gene expression changes as a product of both treamtent and genotype using Affymetrix microarray.
Pharmacogenomics of Chemically Distinct Classes of Keap1-Nrf2 Activators Identify Common and Unique Gene, Protein, and Pathway Responses In Vivo.
Sex, Age, Specimen part
View SamplesTest compound one, 5,6-benzoflavone (BNF), was known to act through both the Ah receptor and Nrf2 receptor pathways, while test compounds two and three, 3H-1,2-dithiole-3-thione (D3T) and 4-methyl-5-pyrazinyl-3H-1,2-dithiole-3-thione (OLT), were known to act through the Nrf2 receptor pathway. Furthermore, D3T is known to be more potent and efficacious than OLT for Nrf2 activation. OLT has been shown to exhibit 20-50% of the efficacy of D3T for inhibition of alfatoxin-induced heptic foci. Nonetheless, because OLT is an approved drug, it is currently being evaluated in human phase II intervention trials of biomarkers of alfatoxin-related hepatocellular carcinoma. More recently, BNF was shown to be an effective chemopreventive agent in the rat mammary carcinogen model, inhibiting 7,12-dimethylbenz(a)anthracene DNA adduct formation in liver and mammary cells by 96 and 83% respectively.
Analyzing microarray data with transitive directed acyclic graphs.
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View SamplesCombining genome-wide microarray and functional analyses, we found that EGFR activation abrogates barrier function, increasing transepidermal water loss (TEWL) and transepithelial permeability of water-soluble ions and higher molecular weight dextrans, in part by disrupting the expression of tight junction proteins. EGF decreases certain lipid matrix free fatty acids and ceramides by its actions to repress the expression of specific biosynthetic enzymes.
EGFR regulation of epidermal barrier function.
Specimen part
View SamplesYeast transcription factor Yap1 mediates adaptive response against H2O2 and the cystein thiol reactive Michael acceptor, N-ethylmaleimid (NEM) and acrolein. The response against H2O2 was found to be distinct from that against NEM and acrolein.
Yap1 activation by H2O2 or thiol-reactive chemicals elicits distinct adaptive gene responses.
Treatment
View SamplesThe activities of the dithiolethione analogs, D3T, OLT, and TBD are pharmacologically well-understood. These compounds act as chemopreventive agents whose ability is to block or diminish early stages of carcinogenesis. In addition, the three compounds are classified as monofunctional Phase II enzyme inducers and activate the same pathway, namely the Keap1-Nrf2 signal pathway. The three dithiolethiones were showed to ameliorate the AFB1-induced toxicity through increasing phase II enzymes including glutathione S-transferase (GST). The parent D3T was observed to be the most potent chemoprotective agent. Oltipraz, a clinically approved drug, has been shown to exhibit less efficacy than its analogs for inhibition of aflatoxin-induced hepatic foci.TBD was suggested to be better than OLT as a chemopreventive agent because of its reduced toxicity profile.
Chemical genomics of cancer chemopreventive dithiolethiones.
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View SamplesTranscriptome analysis of total RNA from C57BL/6 epididymal adipose tissue samples
No associated publication
Sex, Specimen part
View SamplesTCDD increased expression of numerous differentiation specific genes and decreased expression of numerous genes involved in mitochondrial health and redox homeostasis
2,3,7,8-Tetrachlorodibenzo-p-dioxin-mediated production of reactive oxygen species is an essential step in the mechanism of action to accelerate human keratinocyte differentiation.
Specimen part, Cell line
View SamplesWe grew MDA-MB231 cells in a media that had been reconstituted with water that was treated by the Bio-Electric Field Enhancement device generated direct current dielectrophoretic electromagnetic field (Treated group) and cells that were grown in media that was reconstituted with water that was not treated by the BEFE device dc DEP EMF. They were grown for 3 days in each of these media and then analyzed with Affymetrix 2.0 Microarrary Analyses. It was an experimental controlled design.
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Cell line
View SamplesTo better understand the mechanisms involved in aluminum (Al) toxicity and tolerance in plants, microarray technology was used to evaluate changes in gene expression in Arabidopsis thaliana under Al stress. With the use of Affymetrix Arabidopsis ATH1 Genechip, a comparison of RNA expression profiles was made between control and Al-treated Arabidopsis seedlings. A total of 256 genes were identified as Al-responsive. Ninety-four genes were shown to be up-regulated and 162 were down-regulated; comprising 1.1% of the 24,000 Arabidopsis genes. Real-time RT-PCR was used to confirm the microarray data. RNAs associated with known protein functions were classified into categories. The analysis showed that a large number of transcription factors and several putative signaling components were up-regulated by aluminum. Chloroplast structural and photosynthetic genes were, in general, down-regulated. A number of previously identified Al-responsive genes showed similar expression pattern changes in this study. For example, GST, Auxin-regulated, Peroxidase, and Chitinase, were found to be up-regulated by Al-stress, whereas, genes such as Wali 3 and Wali 4, were down-regulated. We also identified several up-regulated genes involved in vacuolar signaling, sorting and docking. Three genes were also up-regulated by Al-stress, Ras GTP-binding protein, ABC-cassette binding, and the AtELP1 receptor genes, have previously been documented as responsive to drought and/or oxidative stress and may play important roles the detoxification of Al ions by transportation and storage into root vacuoles. Ultrastructural changes in the roots tips cells of Arabidopsis were evaluated using TEM and EDXMA with SEM. Results using combined TEM and SEM-EDXMA showed that Al accumulattion in the root tip of Arabidopsis was detectable. The coupling these techniques can be useful for measuring Al in situ in cellular and sub cellular section of plant roots.
No associated publication
No sample metadata fields
View SamplesTrophoblast stem cells lack MAP3K4 activity (TSKI4 cells) switch from epithelial phenotype to intermediate phenotype. Loss of epithelial phenotype is due to the loss of CBP histone acetyltransferase activity and the gain of histone deacetylase HDAC6 expression and activity. In our work, we identify a small network of 183 genes whose expression is co-regulated by MAP3K4, CBP, and HDAC6. Further, we define the key role of one of these co-regulated genes, Rel, in inducing epithelial phenotype in intermediate TSKI4 cells.
Coordinated regulation of Rel expression by MAP3K4, CBP, and HDAC6 controls phenotypic switching.
Specimen part
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