Filters
Technology
Platform
GSE46713
Arabidopsis thaliana
12 Downloadable Samples
Arabidopsis Gene 1.1 ST Array (aragene11st)
Description
The SnRK1 protein kinase, the plant ortholog of mammalian AMPK and yeast Snf1, is activated by the energy depletion caused by adverse environmental conditions. Upon activation, SnRK1 triggers extensive transcriptional changes to restore homeostasis and promote stress tolerance and survival partly through the inhibition of anabolism and the activation of catabolism. Despite the identification of a few bZIP transcription factors as downstream effectors, the mechanisms underlying gene regulation, and in particular gene repression by SnRK1, remain mostly unknown. microRNAs (miRNAs) are 20-24nt RNAs that regulate gene expression post-transcriptionally by driving the cleavage and/or translation attenuation of complementary mRNA targets. In addition to the well-established role of miRNAs as regulators of plant development, mounting evidence implicates miRNAs in the response to environmental stress. Given the involvement of miRNAs in stress responses and the fact that some of the SnRK1-regulated genes are miRNA targets, we postulated that miRNAs drive part of the transcriptional reprogramming triggered by SnRK1 activation. To test this we have performed comparative analyses of the transcriptional response to energy deprivation between WT and dcl1-9, a mutant deficient in miRNA biogenesis.
Publication Title
miRNAs mediate SnRK1-dependent energy signaling in Arabidopsis.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 22 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Purpose: Resistance to endocrine therapy in estrogen receptor-positive (ER+) breast cancer remains a major clinical problem. Recently, the CDK4/6 inhibitor palbociclib combined with letrozole was approved for treatment of ER+ advanced breast cancer, and other CDK4/6 inhibitors are being investigated in combination with different endocrine treatments. However, the role of CDK4/6 in endocrine resistance and their potential as predictive biomarkers of endocrine treatment response remains undefined.
Publication Title
High CDK6 Protects Cells from Fulvestrant-Mediated Apoptosis and is a Predictor of Resistance to Fulvestrant in Estrogen Receptor-Positive Metastatic Breast Cancer.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 17 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
To elucidate the molecular mechanisms of tamoxifen resistance in breast cancer, we performed gene array analysis and identified 366 genes with altered expression in four unique tamoxifen resistant (TamR) cell lines vs the parental tamoxifen sensitive MCF7/S0.5 cell line. Most of these genes were funcationally linked to cell proliferation, death and control gene expression, and include FYN, PRKCA, ITPR1, DPYD, DACH1, LYN, GBP1 and PRLR. Treatment with FYN specific small interfering RNA or a SRC family kinase inhibitor reduced cell growth of TamR cell lines while exerting no significant effect on MCF7/S0.5 cells. Moreover, overexpression of FYN in parental tamoxifen-sensitive MCF7/S0.5 cells resulted in reduced sensitivity to tamoxifen, demonstrating growth and survival promoting function of FYN in MCF7 cells. FYN knockdown in TamR cells led to reduced phosphorylation of 14-3-3 and CDc 25A, suggesting that FYN, by activation of of important cell cycle-associated proteins, may overcome the anti-proliferative effects of tamoxifen. Evaluation of the subcellular localization of FYN in primary breast tumors from two cohorts of endocrine-treated ER+ breast cancer patients, one with advanced disease (N = 47) and the other with early disease (N = 76), showed that in the former, plasma membrane-associated FYN expression strongly correlated with longer progression-free survival (P<0.0002). Similarly, in early breast cancer patients, membrane-associated expression of FYN in the primary breast tumor was significantly associated with increased metastasis-free (P<0.04) and overall (P<0.004) survival independent of tumor size, grade or lymph node status. Our results indicate that FYN has an important role in tamoxifen resistance, and its subcellular localization in breast tumor cells may be an important novel biomarker of response to endocrine therapy in breast cancer.
Publication Title
Gene expression profiling identifies FYN as an important molecule in tamoxifen resistance and a predictor of early recurrence in patients treated with endocrine therapy.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 10 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
The CD44hi compartment in human breast cancer is enriched in tumor-initiating cells, however the functional heterogeneity within this subpopulation remains poorly defined. From a human breast cancer cell line with a known bi-lineage phenotype we have isolated and cloned two CD44hi populations that exhibited mesenchymal/Basal B and luminal/Basal A features, respectively. Rather than CD44+/CD24-,Basal B (G4) cells, only CD44hi/CD24lo, epithelioid Basal A (A4) cells retained a tumor-initiating capacity in NOG mice, form mammospheres and exhibit resistance to standard chemotherapy.
Publication Title
Functional heterogeneity within the CD44 high human breast cancer stem cell-like compartment reveals a gene signature predictive of distant metastasis.
Sample Metadata Fields
Specimen part, Disease, Disease stage
View Samples- Mus musculus
- 24 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Expression profiling of pulmonayr fibrosis prone and fibrosis resistant strains of mice with transgenic overexpression of TGF-beta1
Publication Title
Laminin α1 is a genetic modifier of TGF-β1-stimulated pulmonary fibrosis.
Sample Metadata Fields
Treatment
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Cells grown in forced suspension culture mimic the early steps of metastasis. In order to determine what might be driving the ability of TNBC cells to survive in suspension, a global gene expression profiling experiment was performed. Human triple negative breast cancer (TNBC) cell line BT549 was grown in attached or forced suspension conditions for 24 hours, then RNA was harvested to look for changes in global gene expression.
Publication Title
Androgen Receptor Supports an Anchorage-Independent, Cancer Stem Cell-like Population in Triple-Negative Breast Cancer.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 5 Downloadable Samples
Description
Purpose: Development of resistance to tamoxifen is an important clinical issue in the treatment of patients with breast cancer. Tamoxifen resistance may be the result of the acquisition of epigenetic regulation such as DNA methylation within breast cancer cells resulting in changed mRNA expression of genes being pivotal for estrogen dependent growth. Alternatively, tamoxifen resistance may be due to selection of preexisting resistant cells, which may exhibit cancer stem-like characteristics or a combination of the two mechanisms. Methods: To evaluate the contribution of these possible mechanisms to tamoxifen resistance, we applied modified DNA methylation-specific digital karyotyping (MMSDK) and digital gene expression (DGE) in combination with massively parallel sequencing to analyze a well-established tamoxifen resistant cell line model: MCF-7/S0.5 (tamoxifen sensitive parental cell line) and 4 high-dosage tamoxifen selected resistant offspring sublines (MCF-7/TAMR-1, MCF-7/TAMR-4, MCF-7/TAMR-7 and MCF-7/TAMR-8). MMSDK uses BssHII as mapping enzyme (DNA methylation sensitive enzyme). Both MMSDK and DGE use NlaIII and MmeI to produce 20-21 bp tag. The indexed single-end sequencing was performed by Illumina HiSeq 2000 in BGI-Shenzhen. A dynamic programming algorithm-FASTX-Toolkit implemented in Perl was used to trim the adaptor sequence. The trimmed tags were subjected to quality filtering, so that only tags with sequencing quality higher than 30 for more than 80% of the nucleotides were used for subsequent analysis. For MMSDK tag mapping, we generated a simulated reference library, i.e., BssHII reference library, by in silico enzyme digestion of the human genome (hg19, UCSC) regardless of the methylation state. This library was used as reference for subsequent mapping of the tags in the MMSDK analysis. In the DGE analysis, refMrna (hg19, UCSC) was used as reference for mapping cDNA tags. Subsequently, the Burrows–Wheeler Aligner (BWA) procedure for aligning the MMSDK and DGE tags to the simulated BssHII reference library and refMrna reference library, respectively, was applied. Results: MMSDK libraries using BssHII/NlaIII were generated from the parental tamoxifen sensitive subline MCF-7/S0.5 and the 4 TAMR cell lines: TAMR-1, TAMR-4, TAMR-7 and TAMR-8. The 5 indexed MMSDK libraries were sequenced in one lane and 1.38 Gb clean tag data for all 5 cell lines were obtained, with an average sequencing amount of ~270 Mb per library. On average, 59.5 % of the tags with mapping quality = 20 were mapped back to the simulated BssHII/NlaIII reference library. DGE libraries were also generated from MCF-7/S0.5 and the 4 TAMR cell lines. The 5 indexed DGE libraries were sequenced in one lane and obtained 1.71 Gb clean tag data for all 5 cell lines with an average sequencing amount of ~340 Mb per library. On average, 40.8 % with mapping quality = 20 were mapped back to the simulated NlaIII human transcriptome (refMrna reference library). Our present study demonstrates large differences in global gene expression and DNA methylation profiles between parental tamoxifen-sensitive cell line and 4 high-dosage tamoxifen treatment selected resistant sublines. The tamoxifen resistant cell lines exhibited globally higher methylation level than the parental cell line and an inverse relationship between gene expression and DNA methylation in the promoter regions were noticed. High expression of SOX2 and alterations of other SOX gene family members, E2F gene family members and RB-related pocket protein genes as well as highlighted stem cell pathways imply that cancer initiating cells/stem cells are involved in the resistance to tamoxifen. Overall design: DNA methylation and mRNA expression profiles from tamoxifen sensitive parental cell line MCF-7/S0.5 and 4 high dosage of tamoxifen selected resistant offspring sublines (MCF-7/TAMR-1, MCF-7/TAMR-4, MCF-7/TAMR-7 and MCF-7/TAMR-8) were analyzed by MMSDK and DGE methods, respectively, in combination of massively parallel sequencing, using Illumina HiSeq 2000
Publication Title
Integrative analyses of gene expression and DNA methylation profiles in breast cancer cell line models of tamoxifen-resistance indicate a potential role of cells with stem-like properties.
Sample Metadata Fields
No sample metadata fields
View Samples- Rattus norvegicus
- 10 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
Salt loading (SL) and water deprivation (WD) are experimental challenges that are often used to study the osmotic circuitry of the brain. Central to this circuit is the supraoptic nucleus (SON) of the hypothalamus, which is responsible for the biosynthesis of the hormones, vasopressin (AVP) and oxytocin (OXT), and their transport to terminals that reside in the posterior lobe of the pituitary. Upon osmotic challenge evoked by a change in blood volume or osmolality, the SON undergoes a function related plasticity that creates an environment that allows for an appropriate hormone response. Here, we have described the impact of SL and WD compared to euhydrated (EU) controls in terms of drinking and eating behaviour, body weight and recorded physiological data including circulating hormone data and plasma and urine osmolality. We have also used microarrays to profile the transcriptome of the SON following SL
Publication Title
A comparison of physiological and transcriptome responses to water deprivation and salt loading in the rat supraoptic nucleus.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 33 Downloadable Samples
- Illumina HiSeq 2000
Description
We report mapping of the PAX8 cistrome in three high grade serous ovarian cancer cell lines (KURAMOCHI, OVSAHO, and JHOS4) compared to three benign immortalized fallopian tube cell lines (FT33, FT194, and FT246). We identified a highly conserved PAX8 binding pattern common across benign fallopian tube cell lines that was distinct from the unique PAX8 binding patterns seen in each cancer cell line. Overall design: Comparison of benign and malignant Mullerian cell lines with and without PAX8 knockdown. For each cell line, three distinct siRNAs targeting PAX8 plus a pool of all three siRNAs were examined and compared to both a non-transfected control as well as a control transfected with a non-targeting siRNA.
Publication Title
Epigenetic remodeling regulates transcriptional changes between ovarian cancer and benign precursors.
Sample Metadata Fields
Cell line, Subject
View Samples- Mus musculus
- 6 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Transcriptional and posttranscriptional regulatory networks play a crucial role in the maintenance and adaptation of pancreatic beta-cell function. In this study we show that the levels of the prototypic neuroendocrine miRNA-7 are regulated in islets of obese, diabetic and aged mouse models. Using gain- and loss-of-function models we demonstrate that miR-7 regulates crucial members of the endocrine pancreatic transcriptional network controlling differentiation and insulin synthesis. Importantly, it also directly regulates key proteins in the insulin granule secretory machinery. These results reveal an interconnecting miR-7 genomic circuit that influences beta-cell differentiation, insulin synthesis and release and define a role for miR-7 as an endocrine checkpoint to stabilize beta-cell function during metabolic stress. These findings have implications for miR-7 inhibitors as potential therapies for type 2 diabetes and neurodegenerative diseases.
Publication Title
MicroRNA-7a regulates pancreatic β cell function.
Sample Metadata Fields
Specimen part, Cell line, Treatment
View Samples