This SuperSeries is composed of the SubSeries listed below.
Gene expression signature in advanced colorectal cancer patients select drugs and response for the use of leucovorin, fluorouracil, and irinotecan.
Sex, Age, Specimen part, Subject
View SamplesTo identify genes implicated in metastatic colonization of the liver in colorectal cancer, we collected pairs of primary tumors and hepatic metastases before chemotherapy in 13 patients. We compared mRNA expression in the pairs of patients to identify genes deregulated during metastatic evolution. We then validated the identified genes using data obtained by different groups. The 33-gene signature was able to classify 87% of hepatic metastases, 98% of primary tumors, 97% of normal colon mucosa, and 95% of normal liver tissues in six datasets obtained using five different microarray platforms. The identified genes are specific to colon cancer and hepatic metastases since other metastatic locations and hepatic metastases originating from breast cancer were not classified by the signature. Gene Ontology term analysis showed that 50% of the genes are implicated in extracellular matrix remodeling, and more precisely in cell adhesion, extracellular matrix organization and angiogenesis. Because of the high efficiency of the signature to classify colon hepatic metastases, the identified genes represent promising targets to develop new therapies that will specifically affect hepatic metastasis microenvironment.
Gene expression signature in advanced colorectal cancer patients select drugs and response for the use of leucovorin, fluorouracil, and irinotecan.
Sex, Age, Specimen part, Subject
View SamplesIn patients with advanced colorectal cancer, leucovorin, fluorouracil, and irinotecan (FOLFIRI) is considered as one of the reference first-line treatments. However, only about half of treated patients respond to this regimen, and there is no clinically useful marker that predicts response. A major clinical challenge is to identify the subset of patients who could benefit from this chemotherapy. We aimed to identify a gene expression profile in primary colon cancer tissue that could predict chemotherapy response. Patients and Methods:- Tumor colon samples from 21 patients with advanced colorectal cancer were analyzed for gene expression profiling using Human Genome GeneChip arrays U133. At the end of the first-line treatment, the best observed response, according to WHO criteria, was used to define the responders and nonresponders. Discriminatory genes were first selected by the significance analysis of microarrays algorithm and the area under the receiver operating characteristic curve. A predictor classifier was then constructed using support vector machines. Finally, leave-one-out cross validation was used to estimate the performance and the accuracy of the output class prediction rule. Results:- We determined a set of 14 predictor genes of response to FOLFIRI. Nine of nine responders (100% specificity) and 11 of 12 nonresponders (92% sensitivity) were classified correctly, for an overall accuracy of 95%. Conclusion:- After validation in an independent cohort of patients, our gene signature could be used as a decision tool to assist oncologists in selecting colorectal cancer patients who could benefit from FOLFIRI chemotherapy, both in the adjuvant and the first-line metastatic setting.
Gene expression signature in advanced colorectal cancer patients select drugs and response for the use of leucovorin, fluorouracil, and irinotecan.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrative epigenome-wide analysis demonstrates that DNA methylation may mediate genetic risk in inflammatory bowel disease.
Sex, Age, Specimen part, Subject
View SamplesEpigenetic alterations may provide important insights into gene-environment interaction in inflammatory bowel disease (IBD). Here we observe epigenome-wide DNA methylation differences in 240 newly-diagnosed IBD cases and 190 controls. These include 439 differentially methylated positions (DMPs) and 5 differentially methylated regions (DMRs), which we study in detail using whole genome bisulphite sequencing. We replicate the top DMP (RPS6KA2) and DMRs (VMP1, ITGB2, TXK) in an independent cohort.
Integrative epigenome-wide analysis demonstrates that DNA methylation may mediate genetic risk in inflammatory bowel disease.
Sex, Age, Specimen part
View SamplesWe present primary results from the Sequencing Quality Control (SEQC) project, coordinated by the United States Food and Drug Administration. Examining Illumina HiSeq, Life Technologies SOLiD and Roche 454 platforms at multiple laboratory sites using reference RNA samples with built-in controls, we assess RNA sequencing (RNA-seq) performance for sequence discovery and differential expression profiling and compare it to microarray and quantitative PCR (qPCR) data using complementary metrics. At all sequencing depths, we discover unannotated exon-exon junctions, with >80% validated by qPCR. We find that measurements of relative expression are accurate and reproducible across sites and platforms if specific filters are used. In contrast, RNA-seq and microarrays do not provide accurate absolute measurements, and gene-specific biases are observed, for these and qPCR. Measurement performance depends on the platform and data analysis pipeline, and variation is large for transcriptlevel profiling. The complete SEQC data sets, comprising >100 billion reads (10Tb), provide unique resources for evaluating RNA-seq analyses for clinical and regulatory settings.
A comprehensive assessment of RNA-seq accuracy, reproducibility and information content by the Sequencing Quality Control Consortium.
No sample metadata fields
View SamplesHuntington's disease (HD) is an inherited neurodegenerative disorder caused by an expanded stretch of CAG trinucleotide repeats that results in neuronal dysfunction and death. We made induced pluripotent stem cell (iPSC) lines from HD patients and controls. Though no obvious effects of the CAG expansion on reprogramming or subsequent neural stem cell (NSC) production were seen, HD-NSCs showed CAG expansion-associated gene expression patterns and, upon differentiation, changes in electrophysiology, metabolism, cell adhesion, and ultimately an increased risk of cell death for both medium and longer CAG repeat expansions, with some deficits greater in cells from longer repeat HD NSCs. The HD180 lines were more vulnerable than control lines to cellular stressors and BDNF withdrawal using a range of assays across consortium laboratories. This HD iPSC collection represents a unique and well-characterized resource to elucidate disease mechanisms in HD and provides a novel human stem cell platform for screening new candidate therapeutics.
Induced pluripotent stem cells from patients with Huntington's disease show CAG-repeat-expansion-associated phenotypes.
Specimen part, Disease, Disease stage
View SamplesIn order to study parent-of-origin effects on gene expression, we performed RNAseq analysis (100bp single end reads) of 165 children who formed part of mother/father/child trios where genotype data was available from the HapMap and/or 1000 Genomes Projects. Based on phased genotypes at heterozygous SNP positions, we generated allelic counts for expression of the maternal and paternal alleles in each individual. This analysis reveals significant bias in the expression of the parental alleles for dozens of genes, including both previously known and novel imprinted transcripts. Overall design: This submission contains RNAseq data from 165 children from mother/father/child trios studied as part of the 1000 genomes and/or HapMap projects. We provide raw fastq format reads, and processed read counts per gene. Allelic count information can be provided by directly contacting the authors.
RNA-Seq in 296 phased trios provides a high-resolution map of genomic imprinting.
Specimen part, Cell line, Subject
View SamplesWe performed whole-genome gene expression profiling in Pik3cg-/- mice and subsequent gene ontology clustering of differentially expressed genes compared to wild type mice, in order to investigate the role of Pik3cg in platelet membrane biogenesis and blood coagulation.
Maps of open chromatin guide the functional follow-up of genome-wide association signals: application to hematological traits.
Sex, Specimen part
View SamplesThese samples are part of the ENCODE consortiums proposed time-limited Pilot Study for confirmation of the utility of RNA abundance measurements as a standard reference phenotyping tool.
A user's guide to the encyclopedia of DNA elements (ENCODE).
Cell line
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