Epithelial-mesenchymal transition (EMT) is a pivotal process in development and disease. In carcinogenesis, various signaling pathways are known to trigger EMT by inducing the expression of EMT transcription factors (EMT-TFs) like SNAIL1, ultimately promoting invasion, metastasis and chemoresistance. However, how EMT is executed downstream of EMT-TFs is incompletely understood. Here, using human colorectal cancer (CRC) and mammary cell line models of EMT, we demonstrate that SNAIL1 critically relies on bone morphogenetic protein (BMP) signaling for EMT execution. This activity requires the transcription factor SMAD4 common to BMP/TGFβ pathways, but is TGFβ signaling-independent. Further, we define a signature of BMP-dependent genes in the EMT-transcriptome which orchestrate EMT-induced invasiveness, and are found to be regulated in human CRC transcriptomes and during EMT in vivo. Collectively, our findings substantially augment the knowledge of mechanistic routes whereby EMT can be effectuated, which is relevant for the conceptual understanding and therapeutic targeting of EMT processes.
Canonical BMP Signaling Executes Epithelial-Mesenchymal Transition Downstream of SNAIL1.
Specimen part
View SamplesConverting epithelial into mesenchymal cells through epithelial-mesenchymal transition (EMT) requires massive changes in gene expression. How this is brought about is currently not clear. Here we examined the impact of the EMT master regulator SNAIL1 on the FOXA family of transcription factors which are distinguished by their particular competence to induce chromatin reorganization for the activation of transcriptional enhancer elements. We show that the expression of SNAIL1 and FOXA genes is anti-correlated in transcriptomes of colorectal tumors and cell lines. In two cellular EMT models, ectopically expressed Snail1 downregulates FOXA factors and directly represses FOXA1. To elucidate how FOXA factors contribute to the control of epithelial gene expression, we determined by ChIP-seq data analysis FOXA chromosomal distribution in relation to chromatin structural features characterizing distinct states of transcriptional activity. This revealed a preferential localization of FOXA1 and FOXA2 to transcriptional enhancers at signature genes that distinguish epithelial from mesenchymal colon tumors. To validate the significance of this association, we investigated the impact of FOXA factors on structure and function of transcriptional enhancers at the epithelial genes CDH1, CDX2 and EPHB3. Expression of dominant negative FOXA2 led to chromatin condensation at these enhancer elements. Site- directed mutagenesis of FOXA binding sites in reporter gene constructs and by genome- editing in situ impaired enhancer activity and completely abolished the active chromatin state of the EPHB3 enhancer. Conversely, expression of FOXA factors in cells with inactive CDX2 and EPHB3 enhancers led to chromatin opening and de novo deposition of the H3K4me1 and H3K27ac marks. These findings establish the pioneer function of FOXA factors at enhancer regions of epithelial genes and demonstrate their essential role in maintaining enhancer structure and function. Thus, by repressing FOXA family members, Snail1 targets transcription factors at strategically important positions in gene-regulatory hierarchies which may facilitate transcriptional reprogramming during EMT.
SNAIL1-mediated downregulation of FOXA proteins facilitates the inactivation of transcriptional enhancer elements at key epithelial genes in colorectal cancer cells.
Cell line, Treatment
View SamplesIisomer-specific effects of conjugated linoleic (CLA) supplementation on gene expression with particular consideration of the PPAR 2 Pro12Ala SNP in human adipose tissue.
Isomer-specific effects of CLA on gene expression in human adipose tissue depending on PPARgamma2 P12A polymorphism: a double blind, randomized, controlled cross-over study.
Subject
View SamplesPurpose: Foxp2 is the first and for now the only gene connected to speech and language in humans. Two aminoacid substitutions took place in this protein during recent human evolution, after our split from the last common ancestor with chimpanzees, and are most likely to have undergone positive selection in human lineage (Enard et al., 2002). Methods: Transgenic mice in which the wild-type (murine) version of Foxp2 was replaced with the one bearing two human-specific amino acid substitutions (i.e. "humanized" Foxp2) - Foxp2hum/hum, have been compared to their wild-type (WT) counterparts in terms of behavior, electrophysiology and striatal gene expression. The latter was analyzed through RNA-sequencing performed on pooled indexed libraries on three flow cells on Illumina GAIIx. The reads were mapped to mouse genome (mm9) by TopHat 1.4.1 and were counted using Bedtools. mRNA profiles were obtained with more than 20 million reads for every sample. Differential gene expression was analyzed with DESeq using multifactor model (Anders and Huber, 2010). Results: Wild-type and Foxp2hum/hum mice did not show any significant differences in expression at individual gene level, neither in dorsomedial nor in dorsolateral striatum. However, when genes were grouped into functional categories and analyzed accordingly, this revealed a significant downregulation of functional categories related to synaptic signalling and plasticity in dorsomedial striatum of Foxp2hum/hum mice. Overall design: RNA-sequencing was performed on dorsomedial and dorsolateral striatum of wild-type and Foxp2hum/hum mice, on three flow cells Illumina GAIIx. The libraries from each sample were indexed and pooled together.
Humanized Foxp2 accelerates learning by enhancing transitions from declarative to procedural performance.
No sample metadata fields
View SamplesTumor progression is associated with an immunosuppressive microenvironment that consists of several elements, such as regulatory T cells, type 2 macrophages and myeloid-derived suppressor cells. Here, we identify for the first time a BDCA1+CD14+ population of immunosuppressive cells that resides both in the blood and tumor of melanoma patients. We demonstrated that the presence of these cells in dendritic cell (DC)-based anti-tumor vaccines significantly suppresses CD4+ T cells in an antigen-specific manner. In an attempt to reveal the mechanism of this suppressive activity, we noticed that BDCA1+CD14+ cells express elevated levels of the check-point molecule PD-L1, which thereby hinders T cell proliferation. Importantly, although this suppressive BDCA1+CD14+ population expresses markers of both BDCA1+ DCs and monocytes, functional, transcriptome and proteome analyses clearly revealed that they comprise a unique population of cells that is exploited by tumors to evade immunity. Thus, targeting these cells may improve the efficacy of cancer immunotherapy. Overall design: mRNA profiles of BDCA1+ DCs, BDCA1+CD14+ cells and monocytes, isolated from 3 healthy volunteers, were generated by deep RNA sequencing using HiSeq 2000 System (TruSeq SBS KIT-HS V3,Illumina)
Expansion of a BDCA1+CD14+ Myeloid Cell Population in Melanoma Patients May Attenuate the Efficacy of Dendritic Cell Vaccines.
No sample metadata fields
View SamplesThe experiment aims to identify mRNAs regulated in response to RelA
Role of CCL20 mediated immune cell recruitment in NF-κB mediated TRAIL resistance of pancreatic cancer.
Specimen part, Treatment
View SamplesWe used microarrays to detail the global gene expression changes following apical infection of porcine choroid plexus epithelial cells (PCPEC) with Streptococcus suis (S. suis)
In vitro transcriptome analysis of porcine choroid plexus epithelial cells in response to Streptococcus suis: release of pro-inflammatory cytokines and chemokines.
Specimen part
View SamplesTo identify genes that are regulated from the lncRNA ANRIL (EXON 13), we designed inducible short hairpin RNA constructs and stable integrated them into HEK cells
The large non-coding RNA ANRIL, which is associated with atherosclerosis, periodontitis and several forms of cancer, regulates ADIPOR1, VAMP3 and C11ORF10.
Disease
View SamplesMajor- and minor-group rhinoviruses enter their host by binding to the cell surface molecules ICAM-1 and LDL-R, respectively, which are present on both macrophages and epithelial cells. Although epithelial cells are the primary site of productive HRV infection, previous studies have implicated macrophages in establishing the cytokine dysregulation that occurs during rhinovirus-induced asthma exacerbations. Even though major- and minor-group rhinoviruses are nearly genetically identical, these viruses do not replicate with equal success in monocyte-lineage cell lines. In human primary macrophages, differential mitochondrial activity and signaling pathway activation was observed between major- and minor-group rhinovirus upon initial HRV binding, indicating discordant receptor-dependent response to these rhinovirus types. As well, variances in phosphorylation of kinases (p38, JNK, ERK5) and transcription factors (ATF-2, CREB, CEBP-alpha) were observed between the major- and minor- group HRV treatments. The difference between major- and minor- group HRV activation of signaling pathways was confirmed through RNA-sequencing and observation of differential production of the asthma-relevant cytokines CCL20, CCL2, and IL-10. This is the first report of genetically similar viruses eliciting dissimilar cytokine release, transcription factor phosphorylation, and MAPK activation from macrophages. These results suggest that receptor dependence plays a role in establishing the inflammatory microenvironment initiated in part by monocytic-lineage cells in the human airway upon exposure to rhinovirus. Overall design: RNA sequencing of monocyte-derived macrophages after mock infection or infection by HRV16 or HRV1A
Major and minor group rhinoviruses elicit differential signaling and cytokine responses as a function of receptor-mediated signal transduction.
No sample metadata fields
View SamplesSamples used for hybridization consisted of non-pooled (NP) RNA extracts from 8 groups in each of two time periods after drug administration: oil vehicle treated control embryonic limb bud mesoderm and ectoderm, phosphate buffered saline vehicle control embryonic limb bud mesoderm and ectoderm, acetazolamide treated embryonic limb bud mesoderm and ectoderm, and cadmium sulfate treated embryonic limb bud mesoderm and ectoderm. Forty-eight hybridization experiments were on non-pooled (NP) individual RNA extracts.
Microarray analysis of murine limb bud ectoderm and mesoderm after exposure to cadmium or acetazolamide.
No sample metadata fields
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