The mechanisms involved in epithelium-stroma interactions remain poorly understood, despite the importance of the microenvironment during tumorigenesis. Here, we studied the role of Ets2 transcrpiton factor in tumor associated fibroblasts in the MMTV-ErbB2 mammary tumor model. Inactivation of Ets2 specifically in fibroblasts using Fsp-cre significantly reduced tumor growth, in contrast to Ets2 inactivation in epithelium in which no differences in tumor growth were observed.
Ets2 in tumor fibroblasts promotes angiogenesis in breast cancer.
Age, Specimen part
View SamplesThe tumor stroma is believed to contribute to some of the most malignant characteristics of epithelial tumors. However, signaling between stromal and tumor cells is complex and remains poorly understood. Here we show that genetic inactivation of Pten in stromal fibroblasts of mouse mammary glands accelerated the initiation, progression and malignant transformation of mammary epithelial tumors.
Pten in stromal fibroblasts suppresses mammary epithelial tumours.
Age, Specimen part
View SamplesPTEN imparts tumor suppression in mice by cell autonomous and non-autonomous mechanisms. Whether these two tumor suppressor roles are mediated through similar or distinct signaling pathways is not known. Here we generated and analyzed knockin mice that express a series of human cancer-derived mutant alleles of PTEN in either stromal or tumor cell compartments of mammary glands. We find that cell non-autonomous tumor suppression by Pten in stromal fibroblasts strictly requires activation of P-Akt signaling, whereas cell autonomous tumor suppression in epithelial tumor cells is independent of overt canonical pathway activation
Noncatalytic PTEN missense mutation predisposes to organ-selective cancer development in vivo.
Age, Specimen part
View SamplesNotch signaling is one of the central regulators of differentiation in a variety of organisms and tissue types. Within the hematopoietic system, Notch is essential for the emergence of definitive HSC during fetal life and controls adult HSC differentiation to the T-cell lineage. Notch activation is controlled by the gamma-secretase complex complex, composed of presenilin, nicastrin (Ncstn), anterior pharynx-1 (Aph1), and presenilin enhancer-2
A novel tumour-suppressor function for the Notch pathway in myeloid leukaemia.
Sex, Age
View SamplesNotch signaling is one of the central regulators of differentiation in a variety of organisms and tissue types. Within the hematopoietic system, Notch is essential for the emergence of definitive HSC during fetal life and controls adult HSC differentiation to the T-cell lineage. Notch activation is controlled by the gamma-secretase complex complex, composed of presenilin, nicastrin (Ncstn), anterior pharynx-1 (Aph1), and presenilin enhancer-2
A novel tumour-suppressor function for the Notch pathway in myeloid leukaemia.
Sex, Age
View SamplesNotch signaling is one of the central regulators of differentiation in a variety of organisms and tissue types. Within the hematopoietic system, Notch is essential for the emergence of definitive HSC during fetal life and controls adult HSC differentiation to the T-cell lineage. Notch activation is controlled by the gamma-secretase complex complex, composed of presenilin, nicastrin (Ncstn), anterior pharynx-1 (Aph1), and presenilin enhancer-2
A novel tumour-suppressor function for the Notch pathway in myeloid leukaemia.
Sex, Age
View SamplesCD8 T cells play a crucial role in immunity to infection and cancer. They are maintained in constant numbers, but upon stimulation with antigen undergo a developmental program characterized by distinct phases encompassing the expansion and then contraction of antigen-specific populations, followed by the persistence of long-lived memory cells. Although this predictable pattern of a CD8 T cell response is well established, the underlying cellular mechanisms regulating the transition to memory remain undefined. Here we show that TRAF6, an adapter protein in the TNF-receptor (TNFR) and IL-1R/TLR superfamily, regulates CD8 T cell memory development following infection by modulating fatty acid metabolism. We show that mice with a T cell-specific deletion of TRAF6 mount robust primary CD8 T cell effector responses, but have a profound defect in their ability to generate memory. This defect is CD8 T cell intrinsic and is characterized by the disappearance of antigen-specific cells in the weeks following primary immunization. Microarray analyses revealed that TRAF6-deficient CD8 T cells from early timepoints following immunization exhibit altered expression of genes that regulate fatty acid metabolism. Consistent with this, activated CD8 T cells lacking TRAF6 are unable to upregulate mitochondrial -oxidation in response to growth factor withdrawal in vitro. Treatment with drugs that induce fatty acid oxidation enabled CD8 T cell memory generation in the absence of TRAF6. Remarkably, these treatments also increased CD8 T cell memory in wild type mice, and consequently were able to significantly improve the efficacy of an experimental anti-cancer vaccine.
Enhancing CD8 T-cell memory by modulating fatty acid metabolism.
Specimen part, Time
View SamplesVascular smooth muscle cells (VSMC) are important for contraction, blood flow distribution and regulation of blood vessel diameter, but to what extent they contribute to the integrity of blood vessels and blood-brain barrier function is less well understood. In this report, we explored the impact of the progressive loss of VSMC in the Notch3-/- mouse on blood vessel integrity in the central nervous system
Notch3 is necessary for blood vessel integrity in the central nervous system.
Age, Specimen part
View SamplesThe blood-brain barrier (BBB) consists of specific physical barriers, enzymes and transporters, which together maintain the necessary extracellular environment of the central nervous system (CNS). The main physical barrier is found in the CNS endothelial cell, and depends on continuous complexes of tight junctions combined with reduced vesicular transport. Other possible constituents of the BBB include extracellular matrix, astrocytes and pericytes, but the relative contribution of these different components to the BBB remains largely unknown. Here we demonstrate a direct role of pericytes at the BBB in vivo. Using a set of adult viable pericyte-deficient mouse mutants we show that pericyte deficiency increases the permeability of the BBB to water and a range of low-molecular-mass and high-molecular-mass tracers. The increased permeability occurs by endothelial transcytosis, a process that is rapidly arrested by the drug imatinib. Furthermore, we show that pericytes function at the BBB in at least two ways: by regulating BBB-specific gene expression patterns in endothelial cells, and by inducing polarization of astrocyte end-feet surrounding CNS blood vessels. Our results indicate a novel and critical role for pericytes in the integration of endothelial and astrocyte functions at the neurovascular unit, and in the regulation of the BBB.
Pericytes regulate the blood-brain barrier.
Sex, Age, Specimen part
View SamplesThe human cytomegalovirus (HCMV) encodes the chemokine receptor US28 that exhibits constitutive activity. NIH-3T3 cells stably transfected with US28 present a pro-angiogenic and transformed phenotype both in vitro and in vivo.
The human cytomegalovirus-encoded chemokine receptor US28 promotes angiogenesis and tumor formation via cyclooxygenase-2.
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