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Mus musculus
65 Downloadable Samples
Description
It is widely believed that the carcinogenic action of ionizing radiation is due to targeted DNA damage and resulting mutations, but there is also substantial evidence that non-targeted radiation effects alter epithelial phenotype and the stromal microenvironment. Activation of transforming growth factor 1 (TGF) is a non-targeted radiation effect that mediates cell fate decisions following DNA damage and regulates microenvironment composition; it could either suppress or promote cancer. We asked if such non-targeted radiation effects contribute to carcinogenesis by using a novel radiation chimera model. Unirradiated Trp53 null mammary epithelium was transplanted to the mammary stroma, previously divested of endogenous epithelia, of mice previously exposed to a single low (10 -100 cGy) radiation dose. By 300 days, 100% of transplants in irradiated hosts at either 10 or 100 cGy had developed Trp53 null breast carcinomas compared to 54% in unirradiated hosts. Tumor growth rate was also increased by high, but not low, dose host irradiation. In contrast, irradiation of Tgfb1 heterozygote mice prior to transplantation failed to decrease tumor latency, or increase growth rate at any dose. Host irradiation significantly reduced the latency of invasive ductal carcinoma compared to spindle cell carcinoma. However, irradiation of either host genotype significantly increased the frequency of estrogen receptor negative tumors. These data demonstrate two concepts critical to understanding radiation risks. First, non-targeted radiation effects can significantly promote the frequency and alter the features of epithelial cancer. Second, radiation-induced TGF activity is a key mechanism of tumor promotion.
Publication Title
Radiation acts on the microenvironment to affect breast carcinogenesis by distinct mechanisms that decrease cancer latency and affect tumor type.
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Age, Specimen part
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GSE9460- Mus musculus
- 21 Downloadable Samples
Description
expression analysis from a genetically engineered mouse model of osteosarcoma
Publication Title
Conditional mouse osteosarcoma, dependent on p53 loss and potentiated by loss of Rb, mimics the human disease.
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No sample metadata fields
View Samples- Mus musculus
- 20 Downloadable Samples
Description
Preimplantation Genetic Testing (PGT), which encompasses both Preimplantation Genetic Diagnosis (PGD) and Preimplantation Genetic Screening (PGS), is a form of prenatal screening done on embryos conceived through assisted reproduction techniques (ART) prior to the initiation of pregnancy to ensure that only select embryos are used for transfer. PGT is typically performed on 8-cell embryos derived from either in vitro fertilization or intracytoplasmic sperm injection (ICSI) followed by extended culture. PGT requires a highly invasive embryo biopsy procedure that involves 1) incubating embryos in divalent-cation-deficient medium to disrupt cell adhesion, 2) breaching the protective zona pellucida with acid Tyrodes, laser drilling, or mechanical force and 3) aspirating one or two blastomeres. In this study we developed a mouse model of the embryo biopsy procedure inherent to PGT to determine the effect of various aspects of the procedure (incubation in Ca2+/Mg2+-free medium (CMF), acid Tyrodes treatment, blastomere aspiration), performed individually or in combination, on global patterns of gene expression in the resulting blastocysts.
Publication Title
The effect of blastomere biopsy on preimplantation mouse embryo development and global gene expression.
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Sex
View Samples- Mus musculus
- 6 Downloadable Samples
Description
Serum response factor (SRF) is a transcription factor that binds to the serum response element (SRE) of genes that are expressed in response to mitogens. SRF plays essential roles in muscle and nervous system development; however, little is known about the role of SRF during liver growth and function. To examine the function of SRF in the liver, we generated mice in which the Srf gene was specifically disrupted in hepatocytes. The survival of mice lacking hepatic SRF activity was lower than that of control mice; moreover, surviving mutant mice were smaller and had lower blood glucose and triglyceride levels compared with control mice. Srf-deficient livers were also smaller than control livers, hepatocyte morphology was abnormal, and liver-cell proliferation and viability was compromised. Gene array and quantitative RT-PCR analysis of SRF depleted livers revealed a reduction in mRNAs encoding components of the growth hormone/IGF1 pathway, cyclins, several metabolic regulators, and cytochrome p450 enzymes. Conclusion: SRF is essential for hepatocyte proliferation and survival, liver function, and control of postnatal body growth by regulating hepatocyte gene expression.
Publication Title
Hepatocyte expression of serum response factor is essential for liver function, hepatocyte proliferation and survival, and postnatal body growth in mice.
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No sample metadata fields
View Samples- Mus musculus
- 9 Downloadable Samples
Description
Background and Aims: Although the zinc finger transcription factor GATA4 has been implicated in regulating jejunal gene expression, the contribution of GATA4 in controlling jejunal physiology has not been addressed. Methods: We generated mice in which the Gata4 gene was specifically deleted in the small intestinal epithelium. Measurements of plasma cholesterol and phospholipids, intestinal absorption of dietary fat and cholesterol, and gene expression were performed on these animals. Results: Mice lacking GATA4 in the intestine displayed a dramatic block in their ability to absorb cholesterol and dietary fat. Comparison of the global gene expression profiles of control jejunum, control ileum, and GATA4 null jejunum by gene array analysis demonstrated that GATA4 null jejunum lost expression of 53% of the jejunal-specific gene set and gained expression of 47% of the set of genes unique to the ileum. These alterations in gene expression included a decrease in mRNAs encoding lipid and cholesterol transporters as well as an increase in mRNAs encoding proteins involved in bile acid absorption. Conclusion: Our data demonstrate that GATA4 is essential for jejunal function including fat and cholesterol absorption and confirm that GATA4 plays a pivotal role in determining jejunal versus ileal identity.
Publication Title
GATA4 is essential for jejunal function in mice.
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Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 6 Downloadable Samples
Description
To study the role of hepatic nuclear factor alpha (HNF4a in hepatogenesis, we used loxP-Cre technology to eliminate it from developing mouse livers.
Publication Title
Hepatocyte nuclear factor 4alpha orchestrates expression of cell adhesion proteins during the epithelial transformation of the developing liver.
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Specimen part
View Samples- Mus musculus
- 8 Downloadable Samples
Description
To model the potential diabetogenic effects of higher level of HSD11B1 in b-cells of the pancreas in vivo, we created a transgenic model overexpressing HSD11B1 under the mouse insulin I promoter (MIP-HSD1) in diabetes-prone C57Bl/KsJ mice. KsJ wild type and MIP-HSD1 heterozygous mice have been high fat fed for 12 weeks. Pancreata have been perfused with collagenase and islets isolated by hand picking. Isolated islets (around 500) coming from at least 3 mice (around 200/mice) have been directly lysed in Trizol. Total RNA have been extracted by Trizol plus RNA Purification Kit (invitrogen).
Publication Title
Optimal elevation of β-cell 11β-hydroxysteroid dehydrogenase type 1 is a compensatory mechanism that prevents high-fat diet-induced β-cell failure.
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Specimen part
View Samples- Mus musculus, Homo sapiens
- 3 Downloadable Samples
Description
5,6-Dimethylxanthenone-4-acetic acid (DMXAA), a tumor vascular disrupting agent, is shown here to have substantial activity as a single agent against human A375 melanoma xenografts in nude mice (94 % hemorrhagic necrosis after 24 h, and 26 days growth delay following single dose at 25 mg/kg). CD45+ cells in tumor tissue increased 5-fold over the first 3 days after treatment, which was due largely to an influx of CD11b+ Ly6G+ neutrophils. Using murine and human multiplex cytokine assays to dissect the cytokines produced by host stromal cells or by the melanoma cells, it was shown that both the stromal cells and the A375 melanoma cells produced cytokines capable of attracting neutrophils into the tumor. The same xenografts were also analyzed using human and mouse Affymetrix microarrays to separately identify tumor cell-specific (human) and stromal cell-specific (mouse) gene expression changes. DMXAA induced numerous stromal cytokine mRNAs, including IP-10, IL-6, MIP-1/, MIP-2, KC, RANTES, MIG, MCP-1 and IL-1, many of which were also elevated at the protein level. Numerous human cytokine mRNAs were also induced including MCP-1, IL-8, GRO, VEGF, GM-CSF and IL-6, which again was in line with our protein data. Pathway analysis indicated that significant numbers of the stromal mRNAs induced by DMXAA are regulated downstream of TNF-, interferon- and NFB. Our results suggest that DMXAA may have utility in combination therapy for human melanoma through the activation of pro-inflammatory signalling pathways and cytokine expression from both stromal and tumor cells, leading to haemorrhagic necrosis, neutrophil influx and growth inhibition.
Publication Title
Dissection of stromal and cancer cell-derived signals in melanoma xenografts before and after treatment with DMXAA.
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Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 10 Downloadable Samples
Description
Gene expression profile of joint tissue from C3H and interval specific congenic mouse lines (ISCL) following infection with Borrelia burgdorferi
Publication Title
Interval-specific congenic lines reveal quantitative trait Loci with penetrant lyme arthritis phenotypes on chromosomes 5, 11, and 12.
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Specimen part
View Samples- Mus musculus
- 17 Downloadable Samples
Description
During mammalian gastrulation, pluripotent epiblast stem cells migrate through the primitive streak to form the multipotent progenitors of the mesoderm and endoderm germ layers. Msgn1 is a bHLH transcription factor and is a direct target gene of the Wnt/bcatenin signaling pathway. Msgn1 is expressed in the mesodermal compartment of the primitive streak and is necessary for the proper development of the mesoderm. Msgn1 mutants show defects in somitogenesis leading to a lack of trunk skeletal muscles, vertebra and ribs.
Publication Title
The Wnt3a/β-catenin target gene Mesogenin1 controls the segmentation clock by activating a Notch signalling program.
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Specimen part, Treatment
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