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GSE67320
Mus musculus
16 Downloadable Samples
Description
Vinylidene Chloride has been widely used in the production of plastics and flame retardants. Exposure of B6C3F1 to VDC in the 2-year National Toxicology Program carcinogenicity bioassay resulted in a dose-dependent increase in renal cell hyperplasias, adenomas, and carcinomas (RCCs). Global gene expression analysis showed overrepresentation of pathways associated with chronic xenobiotic and oxidative stress in RCCs from VDC-exposed B6C3F1 mice, as well as cMyc overexpression and dysregulation of Tp53 cell cycle checkpoint and DNA damage repair pathways. Trend analysis comparing RCC, VDC-exposed kidney, and vehicle control kidney showed a conservation of pathway dysregulation in terms of overrepresentation of xenobiotic and oxidative stress, and DNA damage and cell cycle checkpoint pathways in both VDC-exposed kidney and RCC, suggesting that these mechanisms play a role in the development of RCC in VDC-exposed mice.
Publication Title
Renal Cell Carcinomas in Vinylidene Chloride-exposed Male B6C3F1 Mice Are Characterized by Oxidative Stress and TP53 Pathway Dysregulation.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
Description
Hepatocellular carcinoma (HCC) is an important cause of morbidity and mortality worldwide. Although the risk factors of human HCC are well known, the molecular characterization of this disease is complex, and treatment options in general remain poor. The use of rodent models to study human cancer has been extensively pursued both through genetically engineered rodents and rodent models used in carcinogenicity and toxicology studies. In particular, the B6C3F1 mouse used in the National Toxicology Program (NTP) 2-year bioassay has been used to evaluate the carcinogenic effects of environmental and occupational chemicals, and other compounds. The high incidence of spontaneous HCC in the B6C3F1 mouse has challenged its use as a model for chemically induced HCC in terms of relevance to the human disease. Using global gene expression profiling, we identify the dysregulation of several mediators similarly altered in human HCC, including re-expression of fetal oncogenes, upregulation of protooncogenes, downregulation of tumor suppressor genes, and abnormal expression of cell cycle mediators, growth factors, apoptosis regulators, and angiogenesis and extracellular matrix remodeling factors. Although important differences in etiology and pathogenesis remain between human and mouse HCC, there are important similarities in global gene expression and the types of signaling networks dysregulated in mouse and human HCC. These data provide further relevance for the use of this model in hazard identification of compounds with potential human carcinogenicity risk, and may help in better understanding mechanisms of tumorigenesis due to chemical exposure in the NTP 2-year carcinogenicity bioassay.
Publication Title
Global gene profiling of spontaneous hepatocellular carcinoma in B6C3F1 mice: similarities in the molecular landscape with human liver cancer.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 1 Downloadable Sample
Description
Introduction: Lung cancer is the leading cause of cancer-related death in people. There are several chemically induced and genetically modified mouse models used to study lung cancer. We hypothesized that spontaneous murine (B6C3F1) lung tumors can serve as a model to study human non-small cell lung cancer (NSCLC). Methods: RNA was extracted from untreated 2-year-old B6C3F1 mouse spontaneous lung (SL) tumors and age-matched normal lung tissue from a chronic inhalation NTP study. Global gene expression analysis was performed using Affymetrix Mouse Genome 430 2.0 GeneChip arrays. After data normalization, for each probe set, pairwise comparisons between groups were made using a bootstrap t-test while controlling the mixed directional false discovery rate (mdFDR) to generate a differential gene expression list. IPA, KEGG, and EASE software tools were used to evaluate the overrepresented cancer genes and pathways. Results: MAPK and TGF-beta pathways were overrepresented within the dataset. Almost all of the validated genes by quantitative real time RT-PCR had comparable directional fold changes with the microarray data. The candidate oncogenes included Kras, Braf, Raf1, Id2, Hmga1, Cks1b, and Foxf1. The candidate tumor suppressor genes included Rb1, Cdkn2a, Hnf4a, Tcf21, Ptprd, Hpgd, Hopx, Ogn, Id4, Hoxa5, Smad6, Smad7, Zbtb16, Cyr61, Dusp4, and Ifi16. In addition, several genes important in lung development were also differentially expressed, such as Smad6, Hopx, Sox4, Sox9 and Mycn. Conclusion: In this study, we have demonstrated that several cancer genes and signaling pathways relevant for human NSCLC were similarly altered in spontaneous murine lung tumors.
Publication Title
Differential transcriptomic analysis of spontaneous lung tumors in B6C3F1 mice: comparison to human non-small cell lung cancer.
Sample Metadata Fields
Disease, Disease stage
View Samples- Mus musculus
- 12 Downloadable Samples
Description
Ginkgo biloba leaf extract (GBE) has been used for centuries in traditional Chinese medicine and today is used as an herbal supplement for various indications such as improving neural function, anti-oxidant and anti-cancer effects. As part of the herbal supplement industry, these compounds are largely unregulated, and may be consumed in large concentrations over extended periods of time. This is of particular concern, because the long-term effects in terms of toxicity and carcinogenicity data is lacking for many herbal products, including GBE. The 2-year B6C3F1 mouse carcinogenicity bioassay indicated a marked dose-related increase in hepatocellular carcinoma (HCC) development associated with exposure to GBE. We have shown that the mechanism of this increase in tumorigenesis is related to a marked increase in the incidence of -catenin mutation, and report a novel mechanism of constitutive -catenin activation through post-translational modification leading to constitutive Wnt signaling and unregulated growth signaling and oncogenesis. Furthermore, using global gene expression profiling, we show that GBE-induced HCC exhibit overrepresentation of gene categories associated with human cancer and HCC signaling including upregulation of relevant oncogenes and suppression of critical tumor suppressor genes, as well as chronic oxidative stress, a known inducer of calpain-mediated degradation and promoter of hepatocarcinogenesis in humans. These data provide a molecular mechanism to GBE-induced HCC in B6C3F1 mice that is relevant to human cancer, and provides relevant molecular data that will provide the groundwork for further risk assessment of unregulated compounds, including herbal supplements.
Publication Title
Hepatocellular carcinomas in B6C3F1 mice treated with Ginkgo biloba extract for two years differ from spontaneous liver tumors in cancer gene mutations and genomic pathways.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 15 Downloadable Samples
Description
Objectives: To identify similarities and differences in gene expression data in the MEK/ERK and PI3K pathways and to determine how histone modification affects these same pathways. Goal: To identify and functionally characterize novel targets of these signaling pathways in the context of chondrocyte differentiation.
Publication Title
Regulation of gene expression by PI3K in mouse growth plate chondrocytes.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 10 Downloadable Samples
Description
The aim of the present study was to compare, on a statistical basis, the performance of different microarray platforms to detect differences in gene expression in a realistic and challenging biological setting. Gene expression profiles in the hippocampus of five wild-type and five transgenic C-doublecortin-like kinase mice were evaluated with five microarray platforms: Applied Biosystems, Affymetrix, Agilent, Illumina and home-spotted oligonucleotide arrays. We observed considerable overlap between the different platforms, the overlap being better detectable with significance level-based ranking than with a p-value based cut-off. Confirming the qualitative agreement between platforms, Pathway analysis consistently demonstrated aberrances in GABA-ergic signalling in the transgenic mice, even though pathways were represented by only partially overlapping genes on the different platforms.
Publication Title
Can subtle changes in gene expression be consistently detected with different microarray platforms?
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 8 Downloadable Samples
Description
MnTBAP reversed insulin resistance without significant alteration to gene expression
Publication Title
The transcriptional response to oxidative stress is part of, but not sufficient for, insulin resistance in adipocytes.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 26 Downloadable Samples
Description
Brown fat generates heat via the mitochondrial uncoupling protein UCP1, defending against hypothermia and obesity. Recent data suggest that there are two distinct types of brown fat: classical brown fat derived from a myf-5 cellular lineage and UCP1-positive cells that emerge in white fat from a non-myf-5 lineage. Here, we report the isolation of beige cells from murine white fat depots.
Publication Title
Beige adipocytes are a distinct type of thermogenic fat cell in mouse and human.
Sample Metadata Fields
Cell line
View Samples- Mus musculus
- 6 Downloadable Samples
Description
To guarantee blood supply throughout adult life hematopoietic stem cells (HSCs) need to carefully balance between self-renewing cell divisions and quiescence. Identification of genes controlling HSC self-renewal is of utmost importance given that HSCs are the only stem cells with broad clinical applications. Transcription factor PU.1 is one of the major regulators of myeloid and lymphoid development. Recent reports suggest that PU.1 mediates its functions via gradual expression level changes rather than binary on/off states. So far, this has not been considered in any study of HSCs and thus, PU.1s role in HSC function has remained largely unclear. Here we demonstrate using hypomorphic mice with an engineered disruption of an autoregulatory feedback loop that decreased PU.1 levels resulted in loss of key HSC functions, all of which could be fully rescued by restoration of proper PU.1 levels via a human PU.1 transgene. Mechanistically, we found excessive HSC cell divisions and altered expression of cell cycle regulators whose promoter regions were bound by PU.1 in normal HSCs. Adequate PU.1 levels were maintained by a mechanism of direct autoregulation restricted to HSCs through a physical interaction of a -14kb enhancer with the proximal promoter. Our findings identify PU.1 as novel regulator controling the switch between cell division and quiescence in order to prevent exhaustion of HSCs. Given that even moderate level changes greatly impact stem cell function, our data suggest important therapeutic implications for leukemic patients with reduced PU.1 levels. Moreover, we provide first proof, that autoregulation of a transcription factor, PU.1, has a crucial function in vivo. We anticipate that our concept of how autoregulation forms an active chromosomal conformation will impact future research on transcription factor networks regulating stem cell fate.
Publication Title
Sustained PU.1 levels balance cell-cycle regulators to prevent exhaustion of adult hematopoietic stem cells.
Sample Metadata Fields
Specimen part
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