E-cadherin downregulation in cancer cells is associated with epithelial-to-mesenchymal transition (EMT) and metastatic prowess, but the underlying mechanisms are incompletely characterized. In this study, we probed E-cadherin expression at the plasma membrane as a functional assay to identify genes involved in E-cadherin downregulation. The assay was based on the E-cadherin-dependent invasion properties of the intracellular pathogen Listeria monocytogenes. On the basis of a functional readout, automated microscopy and computer-assisted image analysis were used to screen siRNAs targeting 7,000 human genes. The validity of the screen was supported by its definion of several known regulators of E-cadherin expression, including ZEB1, HDAC1 and MMP14. We identified three new regulators (FLASH, CASP7 and PCGF1), the silencing of which was sufficient to restore high levels of E-cadherin transcription. Additionally, we identified two new regulators (FBXL5 and CAV2), the silencing of which
Novel strategies to enforce an epithelial phenotype in mesenchymal cells.
Age, Specimen part, Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Synthetic vulnerabilities of mesenchymal subpopulations in pancreatic cancer.
Specimen part
View SamplesMalignant neoplasms adapt and evolve in response to changes in oncogenic signaling, tumor microenvironmental stresses,and therapeutic interventions. Cancer cell plasticity in response to these evolutionary pressures is foundational to tumor progression and maintenance and therapeutic resistance. Here, to elucidate the underlying molecular and cellularmechanisms of cancer cell plasticity, integrated system-level, functional and genetic analyses were conducted in a conditional oncogenic Kras model of pancreatic ductal adenocarcinoma (PDAC), amalignancy displaying remarkable phenotypic diversityand morphological heterogeneity. In this model, stochastic extinction of oncogenic Krassignaling and emergence ofKras-independent escaper populationsis associated withde-differentiation and aggressive biological behavior.Transcriptomic and functional analyses ofKras-independent escapers reveal mesenchymal reprogramming driven by aSmarcb1/Mycnetwork and independence from MAPK signaling.A somatic mosaic model of PDAC which can track evolving subpopulations shows that depletion of Smarcb1 activates theMyc network which results in an anabolic switch to increased protein metabolism and the adaptive activation of ERstress-induced survival pathways.Theelevated protein turnover made mesenchymal sub-populationshighly susceptible topharmacological and genetic perturbation of the cellular proteostatic machinery andthe IRE1-/MKK4 arm of the ER stress response pathway. Specifically, combination regimens impairing the unfolded protein responses (UPR) and the ER stress response can block the emergence of aggressive mesenchymal subpopulations in murine andpatient-derived PDACmodels. These molecular and biological insights inform a potential therapeutic strategy fortargeting aggressive mesenchymal features of PDAC.
Synthetic vulnerabilities of mesenchymal subpopulations in pancreatic cancer.
Specimen part
View SamplesMalignant neoplasms adapt and evolve in response to changes in oncogenic signaling, tumor microenvironmental stresses,and therapeutic interventions. Cancer cell plasticity in response to these evolutionary pressures is foundational to tumor progression and maintenance and therapeutic resistance. Here, to elucidate the underlying molecular and cellularmechanisms of cancer cell plasticity, integrated system-level, functional and genetic analyses were conducted in a conditional oncogenic Kras model of pancreatic ductal adenocarcinoma (PDAC), amalignancy displaying remarkable phenotypic diversityand morphological heterogeneity. In this model, stochastic extinction of oncogenic Krassignaling and emergence ofKras-independent escaper populationsis associated withde-differentiation and aggressive biological behavior.Transcriptomic and functional analyses ofKras-independent escapers reveal mesenchymal reprogramming driven by aSmarcb1/Mycnetwork and independence from MAPK signaling.A somatic mosaic model of PDAC which can track evolving subpopulations shows that depletion of Smarcb1 activates theMyc network which results in an anabolic switch to increased protein metabolism and the adaptive activation of ERstress-induced survival pathways.Theelevated protein turnover made mesenchymal sub-populationshighly susceptible topharmacological and genetic perturbation of the cellular proteostatic machinery andthe IRE1-/MKK4 arm of the ER stress response pathway. Specifically, combination regimens impairing the unfolded protein responses (UPR) and the ER stress response can block the emergence of aggressive mesenchymal subpopulations in murine andpatient-derived PDACmodels. These molecular and biological insights inform a potential therapeutic strategy fortargeting aggressive mesenchymal features of PDAC.
Synthetic vulnerabilities of mesenchymal subpopulations in pancreatic cancer.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome-wide characterization of menin-dependent H3K4me3 reveals a specific role for menin in the regulation of genes implicated in MEN1-like tumors.
Specimen part
View SamplesInactivating mutations in the MEN1 gene predisposing to the multiple endocrine neoplasia type 1 (MEN1) syndrome can also cause sporadic pancreatic endocrine tumors. MEN1 encodes menin, a subunit of MLL1/MLL2-containing histone methyltransferase complexes that trimethylate histone H3 at lysine 4 (H3K4me3). The importance of menin-dependent H3K4me3 in normal and transformed pancreatic endocrine cells is unclear. To study the role of menin-dependent H3K4me3, we performed in vitro differentiation of wild-type as well as menin-null mouse embryonic stem cells (mESCs) into pancreatic islet-like endocrine cells (PILECs). Gene expression analysis and genome-wide H3K4me3 ChIP-Seq profiling in wild-type and menin-null mESCs and PILECs revealed menin-dependent H3K4me3 at the imprinted Dlk1-Meg3 locus in mESCs, and all four Hox loci in differentiated PILECs. Specific and significant loss of H3K4me3 and gene expression was observed for genes within the imprinted Dlk1-Meg3 locus in menin-null mESCs and the Hox loci in menin-null PILECs. Given that the reduced expression of genes within the DLK1-MEG3 locus and the HOX loci is associated with MEN1-like sporadic tumors, our data suggests a possible role for menin-dependent H3K4me3 at these genes in the initiation and progression of sporadic pancreatic endocrine tumors. Furthermore, our investigation also demonstrates that menin-null mESCs can be differentiated in vitro into islet-like endocrine cells, underscoring the utility of menin-null mESC-derived specialized cell types for genome-wide high-throughput studies.
Genome-wide characterization of menin-dependent H3K4me3 reveals a specific role for menin in the regulation of genes implicated in MEN1-like tumors.
Specimen part
View SamplesAcrylamide is a type-2 alkene monomer with established human neurotoxic effects. While the primary source of human exposure to acrylamide is occupational, other exposure sources include food, drinking water, and smoking. In this study, neurobehavioral assays coupled with transcriptional profiling analysis were conducted to assess both behavioral and gene expression effects induced by acrylamide neurotoxicity in rats when administered during early postnatal life. Acrylamide administration in rat pups induced significant characteristic neurotoxic symptoms including increased heel splay, decrease in grip strength, and decrease in locomotor activity. Transcriptome analysis with the Affymetrix Rat Genome 230 2.0 array indicated that acrylamide treatment caused a significant alteration in the expression of genes involved in muscle contraction, pain regulation, and dopaminergic neuronal pathways. First, in agreement with the observed behavioral effects, expression of the Mylpf gene involved in muscle contraction was downregulated in the spinal cord in response to acrylamide. Second, in sciatic nerves, acrylamide repressed the expression of the opioid receptor gene Oprk1 that is known to play a role in neuropathic pain regulation. Finally, in the cerebellum, acrylamide treatment caused a decrease in the expression of the nuclear receptor gene Nr4a2 that is required for development of dopaminergic neurons. Thus, our work examining the effect of acrylamide at the whole-genome level on a developmental mammalian model has identified novel genes previously not implicated in acrylamide neurotoxicity that can be further developed into biomarkers for assessing the risk of acrylamide exposure.
Neurobehavioral and transcriptional effects of acrylamide in juvenile rats.
Sex, Specimen part, Treatment
View SamplesThe recent reports of two circular RNAs (circRNAs) with strong potential to act as microRNA (miRNA) sponges suggest that circRNAs might play important roles in regulating gene expression. However, the global properties of circRNAs are not well understood. We developed a computational pipeline to identify circRNAs and quantify their relative abundance from RNA-seq data. Applying this pipeline to a large set of non-poly(A)-selected RNA-seq data from the ENCODE project, we annotated 7,112 human circRNAs that were estimated to comprise at least 10% of the transcripts accumulating from their loci. Most circRNAs are expressed in only a few cell types and at low abundance, but they are no more cell-type–specific than are mRNAs with similar overall expression levels. Although most circRNAs overlap protein-coding sequences, ribosome profiling provides no evidence for their translation. We also annotated 635 mouse circRNAs, and although 20% of them are orthologous to human circRNAs, the sequence conservation of these circRNA orthologs is no higher than that of their flanking linear exons. The previously proposed miR-7 sponge, CDR1as, is one of only two circRNAs with more miRNA sites than expected by chance, with the next best miRNA-sponge candidate deriving from a primate-specific zinc-finger gene, ZNF91. These results provide a new framework for future investigation of this intriguing topological isoform while raising doubts regarding a biological function of most circRNAs. Overall design: Examination of 9 samples in 1 cell type Note: The ENCODE data we used are under GEO SuperSeries GSE26284 (all samples labeled "_cell_total"). But they were not used in the processing of the U2OS data.
Expanded identification and characterization of mammalian circular RNAs.
No sample metadata fields
View SamplesMEN1 is a tumor suppressor gene loss of which causes lipoma (fatty tumors under the skin) and many other endocrine and non-endocrine tumors. It's target genes in fat cells (adipocytes) are unknown. Gene expression in adipocytes that were in vitro differentiated from mouse embryonic stem cells (mESCs) of Men1-nul l(Men1-KO) and WT mice were compared to assess the expression of genes upon menin loss in adipocytes that could lead to the deveopment of lipoma.
Consequence of Menin Deficiency in Mouse Adipocytes Derived by In Vitro Differentiation.
Specimen part
View SamplesMeg3 is a long non-coding RNA. It's target genes are unknown. The mouse pancreatic beta cell line MIN6-4N was used to assess the expression of genes upon stable Meg3 overexpression
Epigenetic regulation of the lncRNA MEG3 and its target c-MET in pancreatic neuroendocrine tumors.
Specimen part, Cell line
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