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GSE6080
Homo sapiens
9 Downloadable Samples
Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Hepatocytes are polarized epithelial cells whose function depends upon their ability to distinguish between the apical and basolateral surfaces that are located at intercellular tight junctions. It has been proposed that the signaling cascades that originate at these junctions influence cellular activity by controlling gene expression in the cell nucleus. To assess the validity of this proposal with regard to hepatocytes, we depleted expression of the tight junction protein junctional adhesion molecule-A (JAM-A) in the HepG2 human hepatocellular carcinoma cell line. Reduction of JAM-A resulted in a striking change in cell morphology, with cells forming single-layered sheets instead of the normal multi-layered clusters. In the absence of JAM-A, other tight junction proteins were mislocalized, and canaliculi, which form the apical face of the hepatocyte, were consequently absent. While most changes in gene expression were modest, there was a strong transcriptional induction of the adherens junction protein E-cadherin in cells with reduced levels of JAM-A. This increase in E-cadherin was partially responsible for the observed alterations in cell morphology and mislocalization of tight junction proteins. We therefore propose that we have uncovered a novel mechanism for crosstalk between specific components of tight and adherens junctions that can be utilized to regulate adhesion between hepatic cells and to maintain hepatocyte cell polarity.
Publication Title
Junctional adhesion molecule-A is critical for the formation of pseudocanaliculi and modulates E-cadherin expression in hepatic cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 9 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Background and Aims: Although the zinc finger transcription factor GATA4 has been implicated in regulating jejunal gene expression, the contribution of GATA4 in controlling jejunal physiology has not been addressed. Methods: We generated mice in which the Gata4 gene was specifically deleted in the small intestinal epithelium. Measurements of plasma cholesterol and phospholipids, intestinal absorption of dietary fat and cholesterol, and gene expression were performed on these animals. Results: Mice lacking GATA4 in the intestine displayed a dramatic block in their ability to absorb cholesterol and dietary fat. Comparison of the global gene expression profiles of control jejunum, control ileum, and GATA4 null jejunum by gene array analysis demonstrated that GATA4 null jejunum lost expression of 53% of the jejunal-specific gene set and gained expression of 47% of the set of genes unique to the ileum. These alterations in gene expression included a decrease in mRNAs encoding lipid and cholesterol transporters as well as an increase in mRNAs encoding proteins involved in bile acid absorption. Conclusion: Our data demonstrate that GATA4 is essential for jejunal function including fat and cholesterol absorption and confirm that GATA4 plays a pivotal role in determining jejunal versus ileal identity.
Publication Title
GATA4 is essential for jejunal function in mice.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 129 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Epigenetic suppression of the TGF-beta pathway revealed by transcriptome profiling in ovarian cancer.
Sample Metadata Fields
Sex, Specimen part, Cell line, Treatment
View Samples- Homo sapiens
- 95 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Epithelial ovarian cancer is the leading cause of death among gynecologic malignancies. Diagnosis usually occurs after metastatic spread, largely reflecting vague symptoms of early disease combined with lack of an effective screening strategy. Epigenetic mechanisms of gene regulation, including DNA methylation, are fundamental to normal cellular function and also play a major role in carcinogenesis. To elucidate the biological and clinical relevance of DNA methylation in ovarian cancer, we conducted expression microarray analysis of 39 cell lines and 17 primary culture specimens grown in the presence or absence of DNA methyltransferase (DNMT) inhibitors. Two parameters, induction of expression and standard deviation among untreated samples, identified 378 candidate methylated genes, many relevant to TGF-beta signaling. We analyzed 43 of these genes and they all exhibited methylation. Treatment with DNMT inhibitors increased TGF-beta pathway activity. Hierarchical clustering of ovarian cancers using the 378 genes reproducibly generated a distinct gene cluster strongly correlated with TGF-beta pathway activity that discriminates patients based on age. These data suggest that accumulation of age-related epigenetic modifications leads to suppression of TGF-beta signaling and contributes to ovarian carcinogenesis.
Publication Title
Epigenetic suppression of the TGF-beta pathway revealed by transcriptome profiling in ovarian cancer.
Sample Metadata Fields
Sex, Specimen part, Cell line, Treatment
View Samples- Homo sapiens
- 34 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Epithelial ovarian cancer is the leading cause of death among gynecologic malignancies. Diagnosis usually occurs after metastatic spread, largely reflecting vague symptoms of early disease combined with lack of an effective screening strategy. Epigenetic mechanisms of gene regulation, including DNA methylation, are fundamental to normal cellular function and also play a major role in carcinogenesis. To elucidate the biological and clinical relevance of DNA methylation in ovarian cancer, we conducted expression microarray analysis of 39 cell lines and 17 primary culture specimens grown in the presence or absence of DNA methyltransferase (DNMT) inhibitors. Two parameters, induction of expression and standard deviation among untreated samples, identified 378 candidate methylated genes, many relevant to TGF-beta signaling. We analyzed 43 of these genes and they all exhibited methylation. Treatment with DNMT inhibitors increased TGF-beta pathway activity. Hierarchical clustering of ovarian cancers using the 378 genes reproducibly generated a distinct gene cluster strongly correlated with TGF-beta pathway activity that discriminates patients based on age. These data suggest that accumulation of age-related epigenetic modifications leads to suppression of TGF-beta signaling and contributes to ovarian carcinogenesis.
Publication Title
Epigenetic suppression of the TGF-beta pathway revealed by transcriptome profiling in ovarian cancer.
Sample Metadata Fields
Sex, Specimen part, Treatment
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Genome 430A 2.0 Array (mouse430a2)
Description
Genetic disruption of thioredoxin reductase 1 protects against acetaminophen (APAP) toxicity.
Publication Title
A Txnrd1-dependent metabolic switch alters hepatic lipogenesis, glycogen storage, and detoxification.
Sample Metadata Fields
Sex, Specimen part
View Samples- Homo sapiens
- 10 Downloadable Samples
Illumina HiSeq 2000
Description
Retinal pigment epithelium (RPE) cells can be obtained through in vitro differentiation of both embryonic stem cell (ESC) and induced pluripotent stem cells (iPSC) for cell replacement therapy. We have previously identified 87 signature genes relevant to RPE cell differentiation and function through transcriptome analysis of both human ESC- and iPSC-derived RPE as well as normal fetal RPE. Here, we profiled miRNA expression through small RNA-seq in human ESCs and their RPE derivatives. Much like conclusions drawn from our previous transcriptome analysis, we found that the overall miRNA landscape in RPE is distinct from ESCs and other differentiated somatic tissues. We also profiled miRNA expression during intermediate stages of RPE differentiation and identified unique subsets of miRNAs that are gradually up- or downregulated, suggesting dynamic regulation of these miRNAs is associated with the RPE differentiation process. Indeed, the down-regulation of a subset of miRNAs during RPE differentiation is associated with up-regulation of RPE-specific genes, such as RPE65, which is exclusively expressed in RPE. We conclude that miRNA signatures can be used to classify different degrees of in vitro differentiation of RPE from human pluripotent stem cells. We suggest that RPE-specific miRNAs likely contribute to the functional maturation of RPE in vitro, similar to the regulation of RPE-specific mRNA expression. Overall design: Study miRNA in ESC-derived RPE
Publication Title
Identification of miRNA signatures during the differentiation of hESCs into retinal pigment epithelial cells.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Homo sapiens
- 18 Downloadable Samples
- Affymetrix Clariom S Human array (clariomshuman)
Description
The combined influence of oncogenic drivers, genomic instability, and/or DNA damage repair deficiencies increases replication stress in cancer. Cells with high replication stress rely on the upregulation of checkpoints like those governed by CHK1 for survival. Previous studies of the CHK1 inhibitor prexasertib demonstrated activity across multiple cancer types. Therefore, we sought to (1) identify markers of prexasertib sensitivity and (2) define the molecular mechanism(s) of intrinsic and acquired resistance using preclinical models representing multiple tumor types. Our findings indicate that while cyclin E dysregulation is a driving mechanism of prexasertib response, biomarkers associated with this aberration lack sufficient predictive power to render them clinically actionable for patient selection. Transcriptome analysis of a pan-cancer cell line panel and in vivo models revealed an association between expression of E2F target genes and prexasertib sensitivity and identified innate immunity genes associated with prexasertib resistance. Functional RNAi studies supported a causal role of replication fork components as modulators of prexasertib response. Mechanisms which protect cells from oncogene-induced replication stress may safeguard tumors from such stress induced by a CHK1 inhibitor, resulting in acquired drug resistance. Furthermore, resistance to prexasertib may be shaped by innate immunity.
Publication Title
A pan-cancer transcriptome analysis identifies replication fork and innate immunity genes as modifiers of response to the CHK1 inhibitor prexasertib.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
CD133-positive colorectal cancer cells exhibit enhanced tumorigenicity over CD133-negative cells. The CD133+ cells are more interactive with and responsive to their stromal microenvironment because they also express the cognate receptors, such as CXCR4, for ligands produced by their neighboring carcinoma-associated fibroblasts, such as SDF-1 (stromal-derived growth factor).
Publication Title
CD133+ colon cancer cells are more interactive with the tumor microenvironment than CD133- cells.
Sample Metadata Fields
Specimen part, Disease, Disease stage
View Samples- Homo sapiens
- 157 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Peripheral whole blood transcriptome profiles of pregnant women with normal pregnancy and preeclampsia from 10-18 weeks of gestational age enrolled in the Vitamin D Antenatal Asthma Reduction Trial (VDAART).
Publication Title
Early pregnancy vitamin D status and risk of preeclampsia.
Sample Metadata Fields
Sex, Race
View Samples