Hormones and growth factors accelerate cell proliferation of breast cancer cells, and these molecules are well investigated targets for drug development and application. The mechanisms of cell proliferation of breast cancers lacking estrogen receptor (ER) and HER2 have not been fully understood. The purpose of the present study is to find genes that are differentially expressed in breast cancers and that might significantly contribute to cell proliferation in these cancers. Forty tumor samples, consisting of ten each of immunohistochemically ER(+)/HER2(-), ER(+)/HER2(+), ER(-)/HER2(+), and ER(-)/HER2(-) cancer were analyzed using oligonucleotide microarrays. Both genes and tumor samples were subjected to hierarchical clustering. ER(+)/HER2(-) breast cancers and ER(-)/HER2(-) cancers tended to form a tumor cluster, but HER2 positive breast cancers were split into different tumor clusters.
Overexpression of E2F-5 correlates with a pathological basal phenotype and a worse clinical outcome.
No sample metadata fields
View SamplesTo identify a novel target for the treatment of heart failure, we examined gene expression in the failing heart. Among the genes analyzed, 12/15 lipoxygenase (12/15-LOX) was markedly up-regulated in heart failure. To determine whether increased expression of 12/15-LOX causes heart failure, we established transgenic mice that overexpressed 12/15-LOX in cardiomyocytes. Echocardiography showed that 12/15-LOX transgenic mice developed systolic dysfunction. Cardiac fibrosis increased in 12/15-LOX transgenic mice with advancing age, and was associated with the infiltration of macrophages. Consistent with these observations, cardiac expression of monocyte chemoattractant protein-1 (Mcp-1) was up-regulated in 12/15-LOX transgenic mice compared with wild-type mice. Treatment with 12-hydroxy-eicosatetraenotic acid, a major metabolite of 12/15-LOX, increased MCP-1 expression in cardiac fibroblasts and endothelial cells, but not in cardiomyocytes. Inhibition of Mcp-1 reduced the infiltration of macrophages into the myocardium and prevented both systolic dysfunction and cardiac fibrosis in 12/15-LOX transgenic mice. Likewise, disruption of 12/15-LOX significantly reduced cardiac Mcp-1 expression and macrophage infiltration, thereby improving systolic dysfunction induced by chronic pressure overload. Our results suggest that cardiac 12/15-LOX is involved in the development of heart failure and that inhibition of 12/15-LOX could be a novel treatment for this condition.
Cardiac 12/15 lipoxygenase-induced inflammation is involved in heart failure.
Sex, Age
View SamplesMouse thymocytes can be classified into four major subsets based on expression of CD4 and CD8 co-receptors. CD4-CD8- (double negative, DN) cells become CD4+CD8+ (double positive, DP) cells following productive T cell receptor (TCR) beta chain rearrangement. A small proportion of DP cells are selected through interaction of clonal TCRalpha/beta and MHC self peptide complex expressed on thymic stromal cells. DP cell expressing MHC class I-restricted TCR become CD4-CD8+ cells, which will finally differentiate into cytotoxic T cells, while MHC class II restricted selection generates CD4+CD8- helper lineage T cells.
Transcription factor AP4 modulates reversible and epigenetic silencing of the Cd4 gene.
Specimen part
View SamplesMfng, a modulator of Notch signaling, is highly expressed in human claudin-low breast cancer (CLBC). To determine Mfngs roles in CLBC pathogenesis,we knocked down Mfng in a CLBC cell line MDA-MB231, and found that Mfng knockdown altered Notch activation, decreased tumor sphere formation in vitro, and reduced tumor growth in xenograft model. To identify the potential downstream targets of Mfng during CLBC tumorigenesis, we compared the gene expression profiles between xenografts tumor derived from of MDA-MB231 cells carrying Mfng shRNA and the control vector. Mfng, a modulator of Notch signaling, is highly expressed in human claudin-low breast cancer (CLBC). To determine Mfngs roles in CLBC pathogenesis,we knocked down Mfng in a CLBC cell line MDA-MB231, and found that Mfng knockdown caused alteration in Notch activation, associated with decreased tumor sphere formation in vitro, as well as reduced tumor growth in xenograft model. We intend to compare gene expression profiles between xenografts of MDA-MB231 cells carrying Mfng shRNA and the control vector. This project seeks to identify potential downstream targets of Mfng in CLBC.
Manic fringe promotes a claudin-low breast cancer phenotype through notch-mediated PIK3CG induction.
Specimen part, Treatment
View SamplesDuring a binary cell fate decision, a progeny silences the gene expression program associated with the alternative fate. Helper versus cytotoxic lineage decision in the thymus has been studied as a model for gene silencing of alternative lineage genes, including Cd4. While RUNX3 is required for the initiation of Cd4 silencing, it remains unknown how silenced states of Cd4 and other helper lineage genes are maintained. We show that the histone methyltransferase G9a is necessary for heritable silencing of Cd4 and other helper lineage genes in CD8 T cells. Despite normal Cd4 downregulation during the development, G9a-deficient CD8 T cells fail to maintain silencing of helper lineage genes when they repeatedly divide under non-inflammatory conditions. However, Cd4 depression is prevented during division driven by elevated TCR signaling and an inflammatory cytokine signaling. These results reveal the requirement for G9a in silencing of helper lineage genes in CD8 T cells and also suggest that CD8 T cells employ an alternative mechanism to maintain their cellular identity during immune responses. Overall design: RNA-sequencing on CD4+CD8+ G9a KO, CD4–CD8+ G9a KO, and CD4–CD8+ G9a WT T cells after 4 weeks of proliferation in a lymphopenic environment. ChIP-sequencing on H3K9me3 IP''ed from Ehmt2+/+ and Ehmt2-/- CD8+ T cells cultured in vitro with antibodies to CD3 and CD28
Cutting Edge: The Histone Methyltransferase G9a Is Required for Silencing of Helper T Lineage-Associated Genes in Proliferating CD8 T Cells.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The histone methyltransferase SETDB1 represses endogenous and exogenous retroviruses in B lymphocytes.
Specimen part
View SamplesGenome stability relies on epigenetic mechanisms that enforce repression of endogenous retroviruses (ERVs). Current evidence suggests that distinct chromatin-based mechanisms repress ERVs in cells of embryonic origin (histone methylation-dominant) versus more differentiated cells (DNA methylation-dominant). However, the latter aspect of this model has not been tested. Remarkably, and in contrast to the prevailing model, we find that repressive histone methylation catalyzed by the enzyme SETDB1 is critical for suppression of specific ERV families and exogenous retroviruses in committed B-lineage cells from adult mice. The profile of ERV activation in SETDB1-deficient B cells is distinct from that observed in corresponding embryonic tissues, despite the loss of repressive chromatin modifications at all ERVs. We provide evidence that, upon loss of SETDB1, ERVs are activated in a lineage-specific manner depending on the set of transcription factors available to target proviral regulatory elements. These findings have important implications for genome stability in somatic cells, as well as the interface between epigenetic repression and viral latency.
The histone methyltransferase SETDB1 represses endogenous and exogenous retroviruses in B lymphocytes.
Specimen part
View SamplesGenome stability relies on epigenetic mechanisms that enforce repression of endogenous retroviruses (ERVs). Current evidence suggests that distinct chromatin-based mechanisms repress ERVs in cells of embryonic origin (histone methylation-dominant) versus more differentiated cells (DNA methylation-dominant). However, the latter aspect of this model has not been tested. Remarkably, and in contrast to the prevailing model, we find that repressive histone methylation catalyzed by the enzyme SETDB1 is critical for suppression of specific ERV families and exogenous retroviruses in committed B-lineage cells from adult mice. The profile of ERV activation in SETDB1-deficient B cells is distinct from that observed in corresponding embryonic tissues, despite the loss of repressive chromatin modifications at all ERVs. We provide evidence that, upon loss of SETDB1, ERVs are activated in a lineage-specific manner depending on the set of transcription factors available to target proviral regulatory elements. These findings have important implications for genome stability in somatic cells, as well as the interface between epigenetic repression and viral latency. Overall design: Expression profiling and bisulfite PCR sequencing in Setdb1 C/C and Setdb1 D/D pro-B cells
The histone methyltransferase SETDB1 represses endogenous and exogenous retroviruses in B lymphocytes.
No sample metadata fields
View SamplesGerminal center (GC) B cells cycle between two states, the light zone (LZ) and the dark zone (DZ), and in the latter they proliferate and hypermutate their immunoglobulin genes. How this functional transition takes place is still controversial. In this study, we demonstrate that ablation of Foxo1 after GC development led to the loss of the DZ GC B cells and disruption of the GC architecture. Mechanistically, even upon provision of adequate T cell help, Foxo1-deficient GC B cells showed less proliferative expansion than controls. Moreover, we found that the transcription factor BATF was transiently induced in LZ GC B cells in a Foxo1-dependent manner and that deletion of BATF similarly led to GC disruption. Thus, our results are consistent with a model where the switch from the LZ to the DZ is triggered after receipt of T cell help, and suggest that Foxo1-mediated BATF up-regulation is at least partly involved in this switch. Overall design: mRNA profiles of wild-type DZ, LZ, and Foxo1-deficient GC B cells were generated by deep sequencing in triplicate, using Illumina HiSeq 1500.
The transcription factor Foxo1 controls germinal center B cell proliferation in response to T cell help.
Specimen part, Subject
View SamplesIdiopathic pulmonary fibrosis (IPF) is a refractory and lethal interstitial lung disease characterized by alveolar epithelial cells apoptosis, fibroblast proliferation and extra-cellular matrix proteins deposition. Epstein - Barr virus (EBV) has previously been localised to alveolar epithelial cells of IPF patients. In this study we utilised a microarray based differential gene expression analysis strategy to identify potential molecular drivers of EBV associated lung fibrosis. We employed an alveolar epithelial cell line infected with EBV (A-Akata). Lytic phase infection induced in the A-Akata cells by TPA/BA treatment resulted in increase of TGFbeta1 and TIEG1 mRNA expression. Treatment of the A-Akata cells with ganciclovir,
Alveolar epithelial cell injury with Epstein-Barr virus upregulates TGFbeta1 expression.
No sample metadata fields
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