Medulloblastoma (MB) is the most common malignant brain tumor in children. Patients whose tumors exhibit overexpression or amplification of the MYC oncogene (c-MYC) usually have an extremely poor prognosis, but there are no animal models of this subtype of the disease. Here we show that cerebellar stem cells expressing Myc and mutant Trp53 (p53) generate aggressive tumors following orthotopic transplantation. These tumors consist of large, pleiomorphic cells and resemble human MYC-driven MB at a molecular level. Notably, antagonists of PI3K/mTOR signaling, but not Hedgehog signaling, inhibit growth of tumor cells. These findings suggest that cerebellar stem cells can give rise to MYC-driven MB, and identify a novel model that can be used to test therapies for this devastating disease.
An animal model of MYC-driven medulloblastoma.
Specimen part
View SamplesRationale: While modulation of the serotonin transporter (5HTT) has shown to be a risk factor for pulmonary arterial hypertension for almost 40 years, there is a lack of in vivo data about the broad molecular effects of pulmonary inhibition of 5HTT. Previous studies have suggested effects on inflammation, proliferation, and vasoconstriction. The goal of this study was to determine which of these were supported by alterations in gene expression in serotonin transporter knockout mice. Methods: Eight week old normoxic mice with a 5-HTT knock-out (5HTT-/-) and their heterozygote(5HTT+/-) or wild-type(5HTT+/+) littermates had right ventricular systolic pressure(RVSP) assessed, lungs collected for RNA, pooled, and used in duplicate in Affymetrix array analysis. Representative genes were confirmed by quantitative RT-PCR and western blot. Results: RVSP was normal in all groups. Only 124 genes were reliably changed between 5HTT-/- and 5HTT+/+ mice. More than half of these were either involved in inflammatory response or muscle function and organization; in addition, some matrix, heme oxygenase, developmental, and energy metabolism genes showed altered expression. Quantitative RT-PCR for examples from each major group confirmed changes seen by array, with an intermediate level in 5HTT+/- mice. Conclusions: These results for the first time show the in vivo effects of 5HTT knockout in lungs, and show that many of the downstream mechanisms suggested by cell culture and ex vivo experiments are also operational in vivo. This suggests that the effect of 5HTT on pulmonary vascular function arises from its impact on several systems, including vasoreactivity, proliferation, and immune function.
Gene expression in lungs of mice lacking the 5-hydroxytryptamine transporter gene.
No sample metadata fields
View SamplesHopx appears to be needed for persistence of Th1 effector memory cells. IFN-gamma-producing Th cells are significantly reduced in Hopx-deficient mice compared to Hopx-expressing littermates and Hopx-deficient Th1 cells show a defective persistence upon adoptive transfer. Moreover, Hopx protects Th1 cells from Fas-mediated cell death in vitro. To further dissect the role of Hopx and to identify target genes of Hopx, we have performed transcriptome analysis to compare gene expression in Hopx-deficient versus Hopx-competent Th1 cells. In agreement with the role of Hopx in supporting survival of Th1 effector memory cells, anti-apoptotic cells were up-regulated and pro-apoptotic genes were down-regulated in Hopx-competent compared to Hopx-deficient Th1 cells.
Persistence of effector memory Th1 cells is regulated by Hopx.
Sex, Specimen part
View SamplesAmplification of MYCN is the most prominent genetic marker of high-stage neuroblastoma, a childhood tumor originating from the neural crest. We generated a cell line (mNB-A1) from tumors developed in transgenic mouse and treated these cells with DMSO (n=6), the BRD4-inhibitor JQ1 (n=3) or the AURKA-inhibitor MLN8237 (n=3) for 24 h.
A Cre-conditional MYCN-driven neuroblastoma mouse model as an improved tool for preclinical studies.
Specimen part, Cell line, Treatment
View SamplesPrion infection in animals results in neurodegeneration and eventually death. To examine the cellular impact of Prion disease, we profiled non-proliferative fully differentiated C2C12 cells, which can replicate prions to high levels. Results suggest that accumulation of high levels of PrPSc in C2C12 myotubes does not cause any overt cellular dysfunction or molecular pathology.
Infectious prions accumulate to high levels in non proliferative C2C12 myotubes.
Specimen part, Cell line, Treatment, Time
View SamplesThe polytrauma (PT) murine model has unique transcriptomic responses 2 hrs, 1 day and 3 days after injury. We determined with this clinically relevant model that the increased morbidity in the elderly is secondary to a failure of bone marrow progenitors, blood neutrophils, and bronchoalveolar lavage cells to initiate and complete an 'emergency myelopoietic' response, engendering myeloid cells that fail to clear secondary infection. In addition, the elderly appear unable to effectively resolve their inflammatory response to severe injury.
A Detailed Characterization of the Dysfunctional Immunity and Abnormal Myelopoiesis Induced by Severe Shock and Trauma in the Aged.
Sex, Specimen part, Treatment
View Samples[1] Lactic acidosis time course: MCF7 cells were exposed to lactic acidosis for different length of time. We used microarrays to examine the genomic programs of cells incubated under lactic acidosis for different length of time
Lactic acidosis triggers starvation response with paradoxical induction of TXNIP through MondoA.
Cell line, Treatment
View SamplesFamilial pulmonary arterial hypertension (fPAH) is associated with mutations in BMPR2. Many of these mutations occur in the BMPR2 tail domain, leaving the SMAD functions intact. In order to determine the in vivo consequences of BMPR2 tail domain mutation, we created a smooth-muscle specific doxycycline inducible BMPR2 mutation with an arginine to termination mutation at amino acid 899. When these SM22-rtTA x TetO7-BMPR2R899X mice had transgene induced for 9 weeks, starting at 4 weeks of age, they universally developed pulmonary vascular pruning as assessed by fluorescent microangiography. Approximately half the time the induced animals developed elevated right ventricular systolic pressures (RVSP), associated with extensive pruning, muscularization of small pulmonary vessels, and development of large structural pulmonary vascular changes. These lesions included large numbers of macrophages and T-cells in their adventitial compartment, as well as CD133 positive cells in the lumen. Small vessels filled with CD45 positive and sometimes CD3 positive cells were a common feature in all SM22-rtTA x TetO7-BMPR2R899X mice. Gene array experiments show changes in stress response, muscle organization and function, proliferation and apoptosis, and developmental pathways before RVSP increases. Our results show that the primary phenotypic result of BMPR2 tail domain mutation in smooth muscle is pulmonary vascular pruning leading to elevated RVSP, associated with early dysregulation in multiple pathways with clear relevance to PAH. This model should be useful to the research community in examining early molecular and physical events in the development of PAH, and as a platform to validate potential treatments.
Mice expressing BMPR2R899X transgene in smooth muscle develop pulmonary vascular lesions.
No sample metadata fields
View SamplesThe function of ID4 in CLL development was studied in vivo using TCL1 transgenic mouse model that develop leukemia similar to human CLL. TCL1 mice with ID4 single knockout gene have accelerated CLL progression.
Silencing of the inhibitor of DNA binding protein 4 (ID4) contributes to the pathogenesis of mouse and human CLL.
Specimen part
View SamplesBalanced immune responses in airways of patients with asthma are crucial to succesful clearance of viral infection and proper asthma control.
Rhinovirus-induced epithelial RIG-I inflammasome suppresses antiviral immunity and promotes inflammation in asthma and COVID-19.
Subject, Time
View Samples