Ontology highlight
ABSTRACT:
PROVIDER: PRJNA384491 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Primary outcome(s): the allele frequency of RAS gene mutation in circulating tumor DNA
| 2653459 | ecrin-mdr-crc
Project description:We perfomed copy number analysis of young and old monozygotic twin pairs and young and old single-born individuals to identify somatic copy number changes that occur with age in blood DNA. DNA from peripheral blood was run on Illumina genotyping arrays and the R and B-allele-frequency data were used to identify somatic copy number events
2011-12-16 | E-GEOD-34467 | biostudies-arrayexpress
Project description:Background: the transcription of tumor mutations from DNA into RNA has implications for biology, epigenetics and clinical practice. It is not clear if mutations are in general transcribed and, if so, at what proportion to the wild-type allele. Here, we examined the correlation between DNA mutation allele frequency and RNA mutation allele frequency. Methods: we sequenced the exome and transcriptome of tumor cell lines with large copy number variations, identified heterozygous single nucleotide mutations and absolute DNA copy number, and determined the corresponding DNA and RNA mutation allele fraction. Results: we found that 99% of the DNA mutations in expressed genes are expressed as RNA. Moreover, we found a high correlation between the DNA and RNA mutation allele frequency. Exceptions are mutations that cause premature termination codons and therefore activate nonsense-mediated decay. Beyond this, we did not find evidence of any wide-scale mechanism, such as allele-specific epigenetic silencing, preferentially promoting mutated or wild-type alleles. Conclusion: taken together, our data strongly suggest that genes are equally transcribed from all alleles, mutated and wild-type, and thus transcribed in proportion to their DNA allele frequency.
2014-03-05 | E-MTAB-2383 | biostudies-arrayexpress
Project description:Circulating miRNAs are an emerging class of biomarkers correlating their specific expression patterns to disease states. A considerable proportion of hematopoietically-derived miRNAs are present in plasma with the ability to confound the signature of true circulating miRNA species. We use microarray analysis to catalogue a list of 313 haemotopoetic miRNAs and analyze expression profiles of cell-free miRNAs in individual plasma fractions after calibrating for cellular miRNA signals. Comprehensive global maps of bona fide circulating miRNA species are presented, and inter-individual variability and gender-specific expression is explored in populations of healthy individuals. Healthy Caucasian individuals were used to segregate blood into 8 subfractions: white blood cells (WBC)/buffy coat, leukocytes, red blood cells (red blood cells (RBC)), cloudy supernatant (CS), supernatant 1 (S1), supernatant 2 (S2), pellet 1 (P1) and pellet 2 (P2) through differential centrifugation to understand the proportion of cellular miRNAs in each category.
2011-06-17 | E-GEOD-27230 | biostudies-arrayexpress
Project description:To test whether the addition of a peptide nucleic acid (PNA) clamp, which binds WT KRAS at codon 12, can increase the efficacy of mutation detection for KRASG12D within a targeted NGS setting. We tested the effect of clamping the wild-type KRAS sequence in a reference standard (Tru-Q 7, 1.3% Tier from Horizon Diagnostics, Cambridge, UK) with a KRAS c.35G>A mutation (KRASG12D) at an allelic frequency (AF) of 1.3% assessed by digital droplet PCR (ddPCR). We then re-tested the PNA on circulating-free DNA from a patient harbouring a KRASG12D mutation (at an AF of 3.2%, determined by ddPCR). Multiple runs were conducted using 10, 5, 2.5 and 1ng of DNA input.
2017-07-29 | E-MTAB-5718 | biostudies-arrayexpress
Project description:Circulating tumor-reactive lymphocytes (CTRL) present in blood circulation at a very low frequency. We efficiently isolated them based on high-performance microfluidics and MHC multimer binding assay. Using an ultra-low input bulk RNAseq workflow, we systematically characterize the transcriptomic profile of tumor-reactive lymphocytes and identified novel biomarkers for multimer-free isolation. Two animal models were studied - B16 melanoma model and CT-26 colon cancer model.
2023-04-09 | GSE227345 | GEO
Project description:In study, liquid biopsy samples will be obtained from non-small cell lung cancer (NSCLC) including Squamous cell carcinoma, Adenocarcinoma and large cell carcinoma, colorectal carcinoma (CRC) and pancreatic ductal adenocarcinoma (PDAC) patients who undergo treatment according to established standards of care (SoC) at the University Hospital Schleswig-Holstein (UKSH).
This study will observe the overall Variant Allele Frequency (VAF) of circulating tumour Desoxyribonucleic acid (ctDNA) levels over the patient therapeutic treatment course and will correlate these findings with tumour response as well as Kirsten rat sarcoma viral oncogene homolog (KRAS)mutation status.
| 6842 | ecrin-mdr-crc
Project description:In this study 3 pooling experiments were performed. In each of the 3 cohorts, a 'case' and a 'control' blood pool was compared - the goal being to identify single nucleotide polymorphisms with significantly different estimated pooling allele frequencies between cases and controls. For cohort 1, 100 individuals with blue eye color were placed in one pool (the 'control' pool) and 100 individuals with brown eye color were placed in another pool ( the 'case' pool). In cohort 2, 131 individuals with age-related macular degeneration were placed in one pool, with 216 control individuals in another pool. In cohort 3, 100 individuals with pseudoexfoliation syndrome were placed in a case pool - in this case the cohort 2 control sample was used as 'controls'. The blue/brown pools were hybridized to Illumina HumanHap550 arrays. The cohort 2 and 3 pools were hybridized to Illumina 1M arrays. After processing, the raw data are summarized to give pooling allele frequency estimates for each pool. The abstract from the paper describing these data is as follows: Genome-wide association studies (GWAS) have now successfully identified important genetic variants associated with many human traits and diseases. The high cost of genotyping arrays in large datasets remains the major barrier to wider utilization of GWAS. We have developed a novel method in which whole blood from cases and controls respectively is pooled prior to DNA extraction for genotyping. We demonstrate proof of principle by clearly identifying the associated variants for eye color, age-related macular degeneration and pseudoexfoliation syndrome in cohorts not previously studied. Blood pooling has the potential to reduce GWAS cost by several orders of magnitude and dramatically shorten gene discovery time. This method has profound implications for translation of modern genetic approaches to a multitude of diseases and traits yet to be analysed by GWAS, and will enable developing nations to participate in GWAS. Pools were typed with Illumina arrays. Estimates of pooling allele frequency were obtained.
2009-08-08 | E-GEOD-17557 | biostudies-arrayexpress
Project description:Domestication leads to a spectrum of striking behavioral changes whose genetic basis remains largely unknown. Silver foxes have been selectively bred for tame and aggressive behaviors for over 50 years at the Institute for Cytology and Genetics in Novosibirsk, Russia. To further understand the genetic basis and molecular mechanisms underlying tame and aggressive behavioral phenotypes segregating in selected strains of the silver fox, we quantified genome-wide gene expression levels using RNA-seq in two selected brain tissues, right prefrontal cortex and basal forebrain, from 12 aggressive and 12 tame individuals. Expression analysis reveals 146 differentially expressed genes in prefrontal cortex between tame and aggressive individuals at a 5% FDR, and 33 hits were found in basal forebrain. These candidates include genes in key pathways known to be critical to neurological processing, such as serotonin and glutamate receptor pathways. The data relate in interesting ways to neurological and pharmacological effects that are actively being studied to understand human aggression. In addition, we identified 31,000 high quality exonic SNPs, 295 of which show significant allele frequency differences between tame and aggressive individuals at an adjust P-value < 0.05 level from gene dropping simulation based on the entire pedigrees. A non-synonymous change in a glutamate receptor, GRM3, is among these significant SNPs, indicating that expression and allele-frequency changes are hitting the same pathways. These changes in expression level and allele frequency might be the direct response to the artificial selection and will help understand the genetic basis of mammalian domestication process.
2018-05-30 | GSE76517 | GEO
Project description:Liquid biopsy profile which can screen for early CRC. We aimed to depict the profile of early stage CRC as well as for advanced adenomas by combination of current molecular knowledge with microarray technology, using efficient circulating free RNA purification from blood and RNA amplification technologies. Circulating free RNA profile of plasma from colorectal cancer patients, advanced adenomas and healthy colonoscopia subjects. Plasma was drawn from 3 healthy colonoscopia subjects, 4 adanced adenomas subjects and 3 colorectal cancer patients. Circulating free RNA was purified from plasma samples and applied on GeneChip human 1.0 ST Arrays. The 'HuGene_1_0_green_yelow_red_DATASET.xlsx' and 'probe_level_expression_matrix.txt' files contain the primary data that was used to draw the conclusions of the current study. Please note that exon-level' analysis was performed but NO probe summarization to probeset was performed, therefore both data matrices contains non-unique identifiers.
2016-06-15 | E-GEOD-83353 | biostudies-arrayexpress