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Homo sapiens
4 Downloadable Samples
IlluminaGenomeAnalyzerIIx
Description
While genetic mutation is a hallmark of cancer, many cancers also acquire epigenetic alterations during tumorigenesis including aberrant DNA hypermethylation of tumor suppressors as well as changes in chromatin modifications as caused by genetic mutations of the chromatin-modifying machinery. However, the extent of epigenetic alterations in cancer cells has not been fully characterized. Here, we describe the first complete methylome maps at single nucleotide resolution of a low-passage breast cancer cell line and primary human mammary epithelial cells. We find widespread DNA hypomethylation in the cancer cell, primarily at partially methylated domains (PMDs) in normal breast cells. Unexpectedly, genes within these regions are largely silenced in cancer cells. The loss of DNA methylation in these regions is accompanied by formation of repressive chromatin, with a significant fraction displaying allelic DNA methylation where one allele is DNA methylated while the other allele is occupied by histone modifications H3K9me3 or H3K27me3. Our results show a mutually exclusive and complementary relationship between DNA methylation and H3K9me3 or H3K27me3. These results suggest that global DNA hypomethylation in breast cancer is tightly linked to the formation of repressive chromatin domains and gene silencing, thus identifying a potential epigenetic pathway for gene regulation in cancer cells and suggesting a possible new approach toward the development of cancer therapeutics. Overall design: mRNA-Seq of polyA-selected RNA from breast cancer HCC1954 and normal breast HMEC. 36 cycles of sequencing on Illumina platform.
Publication Title
Global DNA hypomethylation coupled to repressive chromatin domain formation and gene silencing in breast cancer.
Sample Metadata Fields
No sample metadata fields
View Samples
GSE11092- Homo sapiens
- 5 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
CD34+ positively isolated from healthy donors (stimulated by G-CSF) with magnetic beads (after blood leukapheresis)
Publication Title
NA-Seq: a discovery tool for the analysis of chromatin structure and dynamics during differentiation.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 52 Downloadable Samples
- Affymetrix Human Exon 1.0 ST Array [transcript (gene) version (huex10st)
Description
Samples were taken from surgically resected tumor specimens from patients with proximal colon cancer. The expression profiles were determined using the Affymetrix GeneChip Human Exon 1.0 ST Array version 2. APC gene mutation status was determined using Sanger sequencing. A classifier for APC mutation status was trained using these expression data.
Publication Title
Wild-type APC predicts poor prognosis in microsatellite-stable proximal colon cancer.
Sample Metadata Fields
Specimen part
View Samples- Populus tremula x populus alba
- 4 Downloadable Samples
- Affymetrix Poplar Genome Array (poplar)
Description
We studied differences in gene expression between Populus P35S::EBB1 lines and control, affecting plant growth and differentiation, and dormancy. We used microarrays to detail the global program of gene expression underlying morphological and developmental changes driven by overexpression of the EBB1 gene.
Publication Title
EARLY BUD-BREAK 1 (EBB1) is a regulator of release from seasonal dormancy in poplar trees.
Sample Metadata Fields
Specimen part
View Samples- Populus tremula x populus alba
- 2 Downloadable Samples
- Affymetrix Poplar Genome Array (poplar)
Description
We study gene expression Populus amiEBB1 lines affecting dormancy. We used microarrays to detail the global program of gene expression underlying morphological and developmental changes droved by expression of artifical micro RNA (ami) targeting EBB1 gene.
Publication Title
EARLY BUD-BREAK 1 (EBB1) is a regulator of release from seasonal dormancy in poplar trees.
Sample Metadata Fields
Specimen part
View Samples- Populus tremula x populus alba
- 10 Downloadable Samples
- Affymetrix Poplar Genome Array (poplar)
Description
Regeneration of transgenic cells remains a major obstacle to research and commercial deployment of transgenic plants for most species.
Publication Title
Genome scale transcriptome analysis of shoot organogenesis in Populus.
Sample Metadata Fields
Sex
View Samples- Homo sapiens
- 12 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Polycystic ovary syndrome (PCOS), the most common cause of anovulatory infertility, is characterized by increased ovarian androgen production, arrested follicle development, and is frequently associated with insulin resistance. These PCOS phenotypes are associated with exaggerated ovarian responsiveness to FSH and increased pregnancy loss. To examine whether the perturbations in follicle growth and the intrafollicular environment affects development of the mature PCOS oocyte, genes that are differentially expressed in PCOS compared to normal oocytes were defined using microarray analysis. This analysis detected approximately 8000 transcripts. Hierarchical clustering and principal component analysis revealed differences in global gene expression profiles between normal and PCOS oocytes. 374 genes had a statistically-significant increase or decrease in mRNA abundance in PCOS oocytes. A subset of these genes was associated with chromosome alignment and segregation during mitosis and/or meiosis, suggesting that increased mRNAs for these proteins may negatively affect oocyte maturation and/or early embryonic development. Of the 374 differentially expressed genes, 68 contained putative androgen receptor, retinoic acid receptor, and/or peroxisome proliferating receptor gamma binding sites, including 9 of the genes involved in chromosome alignment and segregation. These analyses demonstrated that normal and PCOS oocytes that are morphologically indistinguishable and of high quality exhibit different gene expression profiles. Furthermore, altered mRNA levels in the PCOS oocyte may contribute to defects in meiosis and/or mitosis which might impair oocyte competence for early development and therefore contribute to poor pregnancy outcome in PCOS.
Publication Title
Molecular abnormalities in oocytes from women with polycystic ovary syndrome revealed by microarray analysis.
Sample Metadata Fields
No sample metadata fields
View Samples GSE68859- Populus tremula x populus alba
- 12 Downloadable Samples
- Affymetrix Poplar Genome Array (poplar)
Description
We study differences in gene expression between Populus P35S::BL (BL-oe) lines and control, affecting plant growth and differentiation, and dormancy. We used microarrays to detail the global program of gene expression underlying morphological and developmental changes droved by overexpression of BL gene.
Publication Title
BIG LEAF is a regulator of organ size and adventitious root formation in poplar.
Sample Metadata Fields
Specimen part
View Samples- Schizosaccharomyces pombe
- 5 Downloadable Samples
- Affymetrix Yeast Genome 2.0 Array (yeast2)
Description
Positioned nucleosomes limit the access of proteins to DNA and implement regulatory features encoded in eukaryotic genomes. Here we generated the first genome-wide nucleosome positioning map for Schizosaccharomyces pombe and annotated transcription start and termination sites genome-wide. Using this resource we found surprising differences compared to the nucleosome organization in the distantly related yeast Saccharomyces cerevisiae [the cerevisiae data has been published by others (PMID: 17873876) and the raw data is deposited at ArrayExpress(E-MEXP-1172)]. DNA sequence guides nucleosome positioning differently, e.g., poly(dA:dT) elements are not enriched in S. pombe nucleosome-depleted regions (NDRs). Regular nucleosomal arrays emanate more asymmetrically, i.e., mainly co-directionally with transcription, from promoter NDRs, but promoters harbouring the histone variant H2A.Z show regular arrays also upstream. Regular nucleosome phasing in S. pombe has a very short repeat length of 154 base pairs, and requires a remodeler, Mit1, conserved in humans but not found in S. cerevisiae. Nucleosome positioning mechanisms are evidently not universal but evolutionarily plastic.
Publication Title
Schizosaccharomyces pombe genome-wide nucleosome mapping reveals positioning mechanisms distinct from those of Saccharomyces cerevisiae.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 21 Downloadable Samples
- Affymetrix Human Gene 2.0 ST Array (hugene20st)
Description
mRNA expression profiling of pancreatic cancer, comparing adjacent normal tissue, patient tumour and first generation patient derived xenograft tumours
Publication Title
Establishment and Characterisation by Expression Microarray of Patient-Derived Xenograft Panel of Human Pancreatic Adenocarcinoma Patients.
Sample Metadata Fields
Specimen part
View Samples