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Mus musculus
5 Downloadable Samples
Description
Following neural tube closure at around E9.5, the rhombic lip within the rhombomere 1/isthmus region ("upper rhombic lip") produces a sequence of neuronal lineages that populate the brainstem and cerebellum. The transcription factor Atoh1 (Math1) is required for this specialized neurogenesis, although the genetic programs that delineate the temporal cell fate changes downstream of Atoh1 are not well characterized. We examined the gene expresion changes that take place within Atoh1 lineages
Publication Title
Genes expressed in Atoh1 neuronal lineages arising from the r1/isthmus rhombic lip.
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Specimen part
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GSE10606- Mus musculus
- 3 Downloadable Samples
Description
Expression profile for undifferentiated F9 Embryonal Carcinoma cell line
Publication Title
No associated publication
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 4 Downloadable Samples
Description
Ubiquitination is a post-translational mechanism of control of diverse cellular processes. We focus here on the ubiquitin ligase Fbw7, a recently identified hematopoietic tumor suppressor that can target for degradation several important oncogenes including Notch1, c-Myc and cyclin E. We have generated conditional Fbw7 knock-out animals and inactivated the gene in hematopoietic stem cells (HSC) and their differentiated progeny. Deletion of Fbw7 specifically and rapidly affects the HSC compartment in a cell-autonomous manner. Fbw7-/- HSCs show defective maintenance of quiescence, leading to impaired self-renewal and a severe loss of competitive repopulating capacity. Furthermore, Fbw7-/- HSC are unable to colonize the thymus leading to a profound depletion of T cell progenitors. Deletion of Fbw7 in bone marrow stem cells and progenitors leads to the stabilization of c-Myc, a transcription factor previously implicated in HSC self-renewal. On the other hand, neither Notch1 nor cyclin E are stabilized in the bone marrow of Fbw7 deficient mice. Genome-wide transcriptome studies of Fbw7-/- HSC and hematopoietic progenitors indicate that Fbw7 controls, through the regulation of HSC cell cycle entry, the global transcriptional signature that is associated with the quiescent, self-renewing HSC phenotype.
Publication Title
Control of hematopoietic stem cell quiescence by the E3 ubiquitin ligase Fbw7.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 4 Downloadable Samples
Description
The Hedgehog (Hh) signaling pathway is a developmentally conserved regulator of stem cell function. Several reports suggested that Hh signaling is an important regulator of hematopoietic stem cell (HSC) maintenance and differentiation. Here we test this hypothesis in vivo using both gain- and loss-of-function Hh genetic models. Surprisingly, our studies demonstrate that conditional Smoothened (Smo) deletion or over-activation has no significant effects on adult HSC self-renewal and function. Moreover, they indicate a lack of synergism between the Notch and Hh pathways in HSC function, as RBPJ- and Smo-deficiency do not affect hematopoiesis. In agreement with this notion, detailed genome-wide transcriptome analysis reveals that silencing of Hh signaling does not significantly alter the HSC-specific gene expression signature. Our studies demonstrate that the Hh signaling pathway is dispensable for adult HSC function and suggest that the Hh pathway can be targeted in future clinical trials addressing the effect of Hh inhibition on leukemia-initiating cell maintenance.
Publication Title
No associated publication
Sample Metadata Fields
Sex
View Samples- 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.
Sample Metadata Fields
Age, Specimen part
View Samples- Mus musculus
- 14 Downloadable Samples
Description
Recurrent somatic mutations in TET2 and in other genes that regulate the epigenetic state have been identified in patients with myeloid malignancies and in other cancers. However, the in vivo effects of Tet2 loss have not been delineated. We report here that Tet2 loss leads to increased stem-cell self-renewal and to progressive stem cell expansion. Consistent with human mutational data, Tet2 loss leads to myeloproliferation in vivo, notable for splenomegaly and monocytic proliferation. In addition, haploinsufficiency for Tet2 confers increased self-renewal and myeloproliferation, suggesting that the monoallelic TET2 mutations found in most TET2-mutant leukemia patients contribute to myeloid transformation. This work demonstrates that absent or reduced Tet2 function leads to enhanced stem cell function in vivo and to myeloid transformation.
Publication Title
Tet2 loss leads to increased hematopoietic stem cell self-renewal and myeloid transformation.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 11 Downloadable Samples
Description
Early life exposure to antibiotics alters the gut microbiome. These alterations lead to changes in metabolic homeostasis and an increase in host adiposity. We used microarrays to identify metabolic genes that may be up- or down-regulated secondary to antibiotic exposure.
Publication Title
No associated publication
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 4 Downloadable Samples
Description
This is a comparative microarray analysis of 36-65 hybridomas switching at normal low frequencies in vitro vs. selected variants spontaneously switching at 100 fold higher frequencies in vitro.
Publication Title
No associated publication
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 9 Downloadable Samples
Description
Gene expression profiling was carried out on splenocyte mRNA samples collected from 6 animals subject to repeated social threat and 6 animals subject to non-threatening control conditions (pooled into 3 groups of 2). The primary research question is whether gene expression differs in CD11b+ splenocytes from animals exposed to social threat vs non-threatening control conditions.
Publication Title
No associated publication
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 8 Downloadable Samples
Description
Aberrations in epigenetic processes, such as histone methylation, can lead to cancer. Retinoblastoma Binding Protein 2 (RBP2)(also called JARID1A or KDM5A) can demethylate tri- and di-methylated lysine 4 in histone H3, which are epigenetic marks for transcriptionally active chromatin, whereas the MEN1 tumor suppressor promotes H3K4 methylation. Previous studies suggested that inhibition of RBP2 contributed to tumor suppression by pRB. Here we show RBP2 loss promotes cellular differentiation in vitro. We use mouse expression array 430 2.0 array to profile gene expression patterns of Rbp2f/f and Rbp2-/- ES cells in ES cell medium and after 6 days in ES cell medium without LIF.
Publication Title
No associated publication
Sample Metadata Fields
Specimen part
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