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GSE8188
Zea mays
18 Downloadable Samples
Affymetrix Maize Genome Array (maize)
Description
The contribution of epigenetic alterations to natural variation for gene transcription levels remains unclear. In this study, we investigated the functional targets of the maize chromomethylase ZMET2 in multiple inbred lines to determine whether epigenetic changes conditioned by this chromomethylase are conserved or variable within the species. Gene expression microarrays were hybridized with RNA samples from the inbred lines B73 and Mo17, and from near-isogenic derivatives containing the loss-of-function allele zmet2-m1. A set of 126 genes that displayed statistically significant differential expression in zmet2 mutants relative to wild-type plants in at least one of the two genetic backgrounds were identified. Analysis of the transcript levels in both wild-type and mutant individuals revealed that only 10% of these genes were affected in zmet2 mutants in both B73 and Mo17 genetic backgrounds. Over 80% of the genes with expression patterns affected by zmet2 mutations display variation for gene expression between wild-type B73 and Mo17 plants. Further analysis was performed for seven genes that were transcriptionally silent in wild-type B73, but expressed in B73 zmet2-m1, wild-type Mo17 and Mo17 zmet2-m1 lines. Mapping experiments confirmed that the expression differences in wild-type B73 relative to Mo17 inbreds for these genes were caused by cis-acting regulatory variation. Methylation-sensitive PCR and bisulphite sequencing demonstrated that for five of these genes the CpNpG methylation in the wild-type B73 genetic background was substantially decreased in the B73 zmet2-m1 mutant and in wild-type Mo17. A survey of eight maize inbreds reveals that each of these five genes exhibit transcriptionally silent and methylated states in some inbred lines and unmethylated, expressed states in other inbreds, providing evidence for natural variation in epigenetic states for some maize genes.
Publication Title
Natural variation for alleles under epigenetic control by the maize chromomethylase zmet2.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 27 Downloadable Samples
IlluminaHiSeq2000
Description
Ewing's sarcoma family of tumors (ESFT) is an aggressive pediatric bone and soft tissue cancer. It is the prototypical example of mesenchymal tumors driven by a fusion oncogene involving the ewing sarcoma break point region 1 (EWSR1) gene, most frequently– EWS-FLI1. We have discovered that loss of EWSR1 leads to accumulation of R-loops, replication stress and impaired homologous recombination, recapitulating breast cancer 1, early onset (BRCA1) deficiency. EWS-FLI1 acts dominant negatively in ESFT to impart the same phenotypes. Further we demonstrate that in ESFT, BRCA1 predominantly associates with the elongating transcription machinery and is unavailable for DNA strand break repair. Gene expression profiling identified upregulated compensatory mechanisms in ESFT cells to process increased R-loops (RNASEH2 and FEN1) and replication stress (Fanconi Anemia). Taken together, our data identifies BRCA1 sequestration due to transcription stress as the mechanistic basis for ESFT chemosensitivity and suggests potential targets for the much lacking second-line therapy. Overall design: Examination of gene expression of four ESFT cell lines and two control cell lines. Cells were treated to LD65 dose of etoposideand samples collected at 6 hour intervals over 24 hours
Publication Title
EWS-FLI1 increases transcription to cause R-loops and block BRCA1 repair in Ewing sarcoma.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 331 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
We have performed bioinformatic approaches to identify the level of enrichment between gene expression profiles characterizing MSI tumors and gene changes induced in vitro by the PARP-1 inhibitor Phenanthridinone and others using the Connectivity Map tool. In a first step, we have anyzed the expression of 300 colorectal cancers from the MECC study and generated a gene expression signature by microsatellite status. The criteria followed for selection of probe sets and detailed lists to be submitted subsequently to the Connectivity Map have been published previously by us in Clinical Cancer Research in 2009. In a second step, once we observed that deficiency in MRE11 exist among MSI tumors, our interest was focused on assessing if the homologous recombination pathway showed evidence of deregulation in MSI tumors. Therefore, we examined the expression levels of those genes integrated in the KEGG pathway hsa03440 using the previously generated gene expression data set.
Publication Title
MRE11 deficiency increases sensitivity to poly(ADP-ribose) polymerase inhibition in microsatellite unstable colorectal cancers.
Sample Metadata Fields
Sex, Age
View Samples- Homo sapiens
- 424 Downloadable Samples
- Affymetrix Human Exon 1.0 ST Array [transcript (gene) version (huex10st)
Description
Transcriptome analysis of post-mortem brain tissue specimens from three brain regions (BRs), entorinal, temporal and frontal cortices, of 71 Japanese brain-donor subjects to identify genes relevant to the expansion of neurofibrillary tangles. In total, 213 brain tissue specimens (= 71 subjects 3 BRs) were involved in this study. The spreading of neurofibrillary tangles (NFTs), intraneuronal aggregates of highly phosphorylated microtubule-associated protein tau, across the human brain is correlated with the cognitive severity of Alzheimers disease (AD). To identify genes relevant to NFT expansion defined by the Braak stage, we conducted exon array analysis with an exploratory sample set consisting of 213 human post-mortem brain tissue specimens from the entorinal, temporal and frontal cortices of 71 brain-donor subjects: Braak NFT stages 0 (N = 13), III (N = 20), IIIIV (N = 19) and VVI (N = 19). We identified eight genes, RELN, PTGS2, MYO5C, TRIL, DCHS2, GRB14, NPAS4 and PHYHD1, associated with the Braak stage. The expression levels of three genes, PHYHD1, MYO5C and GRB14, exhibited reproducible association on real-time quantitative PCR analysis. In another sample set, including control subjects (N = 30) and patients with late-onset AD (N = 37), dementia with Lewy bodies (N = 17) and Parkinson disease (N = 36), the expression levels of two genes, PHYHD1 and MYO5C, were obviously associated with late-onset AD. Proteinprotein interaction network analysis with a public database revealed that PHYHD1 interacts with MYO5C via POT1, and PHYHD1 directly interacts with amyloid beta-peptide 42. It is thus likely that functional failure of PHYHD1 and MYO5C could lead to AD development.
Publication Title
Genes associated with the progression of neurofibrillary tangles in Alzheimer's disease.
Sample Metadata Fields
Sex, Specimen part, Subject
View Samples- Homo sapiens
- 9 Downloadable Samples
- Illumina HiSeq 4000
Description
We identified a rare coding variant (p.K420Q) in the complement component 7 (C7) gene affecting the risk of Alzheimer's disease. To investigate the cellular effects of the mutant, we performed RNA-seq in cell line overexpression wilt-type and mutant C7. U251 glioma cells with stable expression of mutant APP (K670N/M671L) (U251-APP cells), which produce Aß42 under Dox inducing, were used as the model cell. Total RNA of U251-APP cells overexpressing wild type and mutant C7 proteins were subjected to transcriptome sequencing using Illumina Hiseq 4000 platform. Overall design: C7 overexpression was performed in U251 cell with a stably expression of mutant APP (U251-APP cells) with three biological triplicates for each condition (vector, wild-type, and mutant).
Publication Title
<i>Complement C7</i> is a novel risk gene for Alzheimer's disease in Han Chinese.
Sample Metadata Fields
Cell line, Subject
View Samples- Homo sapiens
- 30 Downloadable Samples
- Affymetrix Human Transcriptome Array 2.0 (hta20)
Description
In this dataset, we included expression data obtained from 30 resected human PDAC tumors, to examine what genes are differentially expressed in different cohorts that might lead to various outcomes
Publication Title
Identification of unique neoantigen qualities in long-term survivors of pancreatic cancer.
Sample Metadata Fields
Specimen part
View Samples