We generated a gene replacement allele of the E-cadherin locus that express an N-cadherin-GFP fusion in ES cells. Expression profiles of homozygous and heterozygous knock-in ES cells were analyzed in comparison to wt ES cells.
Adhesion, but not a specific cadherin code, is indispensable for ES cell and induced pluripotency.
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View SamplesBRCA1, a well-known breast and ovarian cancer susceptibility gene with multiple interacting partners, is predicted to have diverse biological functions. However, to date its only well-established role is in the repair of damaged DNA and cell cycle regulation. In this regard, the etiopathological study of low penetrant variants of BRCA1 provides an opportunity to uncover its other physiologically important functions. Using this rationale, we studied the R1699Q variant of BRCA1, a potentially moderate risk variant, and found that it does not impair DNA damage repair but abrogates the repression of miR-155, a bona fide oncomir. We further show that in the absence of functional BRCA1, miR-155 is up-regulated in BRCA1-deficient mouse mammary epithelial cells, human and mouse BRCA1-deficienct breast tumor cell lines as well as tumors. Mechanistically, we found that BRCA1 represses miR-155 expression via its association with HDAC2, which deacetylates H2A and H3 on the miR-155 promoter. Finally, we show that over-expression of miR-155 accelerates whereas the knockdown of miR-155 attenuates the growth of tumor cell lines in vivo. Taken together, our findings demonstrate a new mode of tumor suppression by BRCA1 and reveal miR-155 as a potential therapeutic target for BRCA1-deficient tumors.
Tumor suppressor BRCA1 epigenetically controls oncogenic microRNA-155.
Specimen part
View SamplesWe examined the functional significance of the R1699Q variant of human BRCA1 gene using a mouse ES cell-based assay.
Tumor suppressor BRCA1 epigenetically controls oncogenic microRNA-155.
Specimen part
View SamplesNotch1 deficient hair matrix keratinocytes have lower mitotic rates, resulting in smaller follicles with fewer cells. In addition, the ratio of melanocytes to keratinocytes is greatly reduced. Microarray was performed to study downstream mechanism of Notch1-deficiency
Bi-compartmental communication contributes to the opposite proliferative behavior of Notch1-deficient hair follicle and epidermal keratinocytes.
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View SamplesBACKGROUND: Peroxisome proliferator-activated receptor g (PPAR g) is a nuclear receptor whose activation has been shown to modulate macrophage and epithelial cell-mediated inflammation. The objective of this study was to use a systems approach for investigating the mechanism by which the deletion of PPAR g in T cells modulates the severity of dextran-sodium sulfate (DSS)-induced colitis, immune cell distribution and global gene expression.
The role of T cell PPAR gamma in mice with experimental inflammatory bowel disease.
No sample metadata fields
View SamplesBACKGROUND: Peroxisome proliferator-activated receptor g (PPAR g) is a nuclear receptor whose activation has been shown to modulate macrophage and epithelial cell-mediated inflammation. The objective of this study was to use a systems approach for investigating the mechanism by which the deletion of PPAR g in epithelial cells modulates the severity of dextran-sodium sulfate (DSS)-induced colitis, immune cell distribution and global gene expression.
Immunoregulatory actions of epithelial cell PPAR gamma at the colonic mucosa of mice with experimental inflammatory bowel disease.
Specimen part
View SamplesBackground: It has been shown previously that administration of Francisella tularensis (Ft) LVS lipopolysaccharide (LPS) protects mice against subsequent challenge with Ft LVS and blunts the pro-inflammatory cytokine response.
Modulation of hepatic PPAR expression during Ft LVS LPS-induced protection from Francisella tularensis LVS infection.
Age, Specimen part
View SamplesC/EBPb is an auto-repressed protein that becomes posttranslationally activated by Ras-MEK-ERK signalling. C/EBPb is required for oncogene-induced senescence (OIS) of primary fibroblasts, but also displays pro-oncogenic functions in many tumour cells. Here, we show that C/EBPb activation by H-RasV12 is suppressed in immortalized/transformed cells, but not in primary cells, by its 30 untranslated region (30UTR). 30UTR sequences inhibited Ras-induced cytostatic activity of C/EBPb, DNA binding, transactivation, phosphorylation, and homodimerization, without significantly affecting protein expression. The 30UTR suppressed induction of senescence-associated C/EBPb target genes, while promoting expression of genes linked to cancers and TGFb signalling. An AU-rich element (ARE) and its cognate RNA-binding protein, HuR, were required for 30UTR inhibition. These components also excluded the Cebpb mRNA from a perinuclear cytoplasmic region that contains activated ERK1/2, indicating that the site of C/EBPb translation controls de-repression by Ras signalling. Notably, 30UTR inhibition and Cebpb mRNA compartmentalization were absent in primary fibroblasts, allowing Ras-induced C/EBPb activation and OIS to proceed. Our findings reveal a novel mechanism whereby non-coding mRNA sequences selectively regulate C/EBPb activity and suppress its anti-oncogenic functions.
3'UTR elements inhibit Ras-induced C/EBPβ post-translational activation and senescence in tumour cells.
Cell line
View SamplesTo examine the role of CREB overexpression in hematopoiesis, we created a model of leukemia in zebrafish by overexpressing the human CREB in the myeloid hematopoietic lineage. Whole transcriptome analysis of kidney-marrow revealed 171 genes differently expressed between CREB- and control-zebrafish (five per group). Interestingly, the integration of this signature with human deposited data revealed that this tumor resembled a human AML at transcriptome level.
CREB engages C/EBPδ to initiate leukemogenesis.
Specimen part
View Samplescompare wild type and Batf-/- B cells activated for 0 1 or 2 days in vitro.
The transcription factor BATF controls the global regulators of class-switch recombination in both B cells and T cells.
Specimen part
View Samples