12400 results for ""statistically+reactive"+taxa+in+microbial+community"

in 14.49 milliseconds.

• Single cell RNA seq of breast cancer stem cells

  RNA sequences of breast cancer have been investigated for many patients. Recently it has been shown that there are intra-heterogeneity in tumor tissues. When the tumor cells were sequenced in bulk condition, only the major populations' mRNA will be detected. With respect to breast cancer, it has been also reported that cancer cells can sub-gropued into cancer stem cells and non-cancer stem cells. Although the mRNA expressions' difference between this two groups has been profoundly investigated, whether each group is composed by unique cell or not is yet to be elucidated. Since cancer stem cells are the thought to be the major contributor of metastasis and/or recurrence, we focused on cancer stem cells in this study. We separated cancer cells into cancer stem cells and non-cancer stem cells exploiting cancer stem cell specific surface markers. Thereafter, we sequenced mRNA of cancer stem cells in single cell resolution. From this result, we examined whether these cells can be sub-grouped or not.

  Study JGAS000305

• Shallow Whole Genome Sequencing of Patient Derived Xenografts

  Chemotherapy is the standard-of-care treatment for metastatic colorectal cancer (mCRC) and benefits some patients, but what distinguishes responders from non-responders is unclear. In this study, we leveraged a comprehensive collection of 27 molecularly annotated patient-derived xenografts to uncover functional predictors of response to 5-FU and irinotecan combination therapy (FOLFIRI) in mCRC. Genetic analyses revealed that treatment sensitivity was marked by genomic scars indicative of BRCAness, suggesting homologous recombination (HR) deficiency as a key determinant. Accordingly, we surveyed a manually curated panel of 44 genes with a documented role in HR for the potential presence of pathogenic mutations. We did not observe a specific enrichment of HR gene mutations based on response to FOLFIRI. This result, combined with the absence of widespread biallelic inactivation of the analyzed genes and the predominance of mutations categorized as variants of unknown significance, suggests that FOLFIRI sensitivity is not primarily governed by underlying mutations in HR genes responsible for mitigating the genotoxic effects of this therapeutic regimen.

  Study EGAS50000000191

• Inferring tumor genomes from peripheral blood i.e. CTCs and plasma-DNA using deep sequencing and targeted enrichment

  In this study we tested whether complex tumor genomes can be inferred from the peripheral blood (plasma DNA /CTCs) of 32 patients with stage IV colorectal carcinoma (CRC). To establish the percentage of mutated plasma DNA fragments we used 8 patient samples with different plasma DNA size distributions and KRAS mutations in their corresponding primary tumors and employed ultra-deep pyrosequencing with 3 different sequencing reaction sizes (i.e., 119 bp, 168 bp, and 323 bp). Furthermore, we used massive parallel sequencing of a panel of 68 CRC-associated genes to establish the mutation spectrum of cancer driver genes in the primary tumors, metastases, and CTCs of two colorectal cancer patients. To investigate, whether mutations found in only one CTC (“private CTC mutations”) are true mutations occurring with allele frequencies below the resolution limits of current detection methods, or whether they are amplification or sequencing artifacts, we performed ultra-deep sequencing of the primary tumors, metastases, plasma DNAs and normal tissues.

  Study EGAS00001000337

• ABO: a 3D stroma-supported culture platform enabling full human B lymphopoiesis for disease modeling and gene therapy development

  Defective B-cell development underlies a large proportion of inborn errors of immunity, but progress in understanding disease mechanisms and of developing therapies has been limited by inadequate human in vitro models. Here, we establish a 3D aggregate culture platform composed of hematopoietic stem and progenitor cells (HSPCs) and mouse bone marrow stromal cells as an assay for efficient B-cell output (the ABO platform). ABOs supported progression through pro-B, pre-B, immature, and transitional B-cell stages, with a transcriptional profile and B-cell receptor (BCR) repertoire diversity closely resembling human bone marrow B-cell ontogeny. ABO-derived B cells exhibited functional signaling and differentiated into class-switched memory and antibody-secreting B cells following CD40-mediated stimulation. The ABO platform reproduced the arrest in B-cell development observed in RAG1-SCID patient–derived HSPCs, which was corrected by lentiviral RAG1 gene therapy. Thus, ABOs provide a clinically relevant platform for modeling B-cell immunodeficiencies and evaluating therapeutic strategies.

  Study EGAS50000001693

• Data upcycling, powered by EGA

  In 2012 a collaborative effort headed by the teams of Carlos Caldas in Cambridge, UK and Samuel Aparicio, Canada, produced a pivotal study aimed at defining the mutational landscape of breast cancer. They gathered a collection of over 2000 breast cancer samples (METABRIC) associated with long-term clinical follow-up. They delineated an array of inherited and somatically acquired genetic variants and associated them to gene expression. This led to the identification of putative cancer-driving events and improved stratification of breast cancer patients. The study elicited huge attention and was tackled as herculean effort by fellow researchers. Cristina Curtis and her colleagues deposited the data in the EGA archive (EGAS00000000083). What they probably could not foresee is that their data would be reused more than 100 times, becoming one of the most downloaded datasets at EGA. In 2015, Frederik S. Varn and colleagues accessed the above-mentioned data from the New Hampshire, USA, to correlate it to transcriptional programs of hematopoietic cells infiltrated in breast tumours and found that those can influence patients' prognosis. Their findings, published in Nature Communications, improved the understanding of the interplay between immune system and cancer. Again, in 2017 the dataset was downloaded by an Italian/Polish collaboration and used to corroborate their mechanistic study that demonstrate how a long non-coding RNA (lncRNA) is aberrantly localized into the chromatin, where it modulates oncogenic isoforms expression, thus contributing to breast cancer. To date, the METABRIC dataset has been reused to contribute to 147 publications. Its impact on breast cancer research is incalculable, and it even spread beyond that, with recent contributions to the understanding of pan-cancer mechanisms and features. Some of the publications are translating into improvements in diagnosis and treatment of different types of breast cancer. This is just an example of how data upcycling can amplify the potential of any dataset, well past the scope of its creation, the imagination of its owners and any geographical border. At EGA, we are proud to empower such fruitful worldwide cycles of knowledge, providing a platform that enables safe sharing of sensitive genetic data.

  Blog data-upcycling-powered-by-ega

• Lineage-specific genome architecture links disease variants to target genes

  Long-range interactions between DNA regulatory elements and their target genes play major roles in gene regulation. The vast majority of interactions are uncharted, constituting a major missing link in understanding genome control. Here we use promoter capture Hi-C to identify interacting regions of 31,253 promoters in 17 human primary haematopoietic cell types. We show that long-range promoter interactions are highly cell-type specific, preferentially linking active promoters and enhancers. Patterns of promoter interactions reflect cell lineage relationships of the hematopoietic tree, consistent with dynamic remodeling of nuclear architecture during differentiation. Interacting regions are enriched for expression quantitative trait loci with effects on their interacting target genes. We exploit this rich resource of interactome maps to connect non-coding disease variants to their target promoters, identifying thousands of new disease-candidate genes, and implicating a number of gene pathways in disease susceptibility. Our results demonstrate the power of promoter interactomes from primary cells to reveal insights into genomic regulatory mechanisms underlying common diseases.

  Study EGAS00001001911

• DNA methylation atlas of normal human cell types

  DNA methylation is a fundamental epigenetic mark that governs chromatin organization, cell identity, and gene expression. Here we describe a human methylome atlas, based on deep whole-genome bisulfite sequencing allowing fragment-level analysis across thousands of unique markers for 39 cell types sorted from 205 healthy tissue samples. Replicates of the same cell-type are >99.5% identical, demonstrating robustness of cell identity programs to genetic variation and environmental perturbation. Unsupervised clustering of the atlas recapitulates key elements of tissue ontogeny, and identifies methylation patterns retained since gastrulation. Loci uniquely unmethylated in an individual cell type often reside in transcriptional enhancers and contain DNA binding sites for tissue-specific transcriptional regulators. Uniquely hyper-methylated loci are rare and are enriched for CpG islands, polycomb targets, and CTCF binding sites, suggesting a novel role in shaping cell type-specific chromatin looping. The atlas provides an essential resource for interpretation of disease-associated genetic variants, and a wealth of potential tissue-specific biomarkers for use in liquid biopsies.

  Study EGAS00001006791

• CPC-GENE Prostate Cancer Heterogeneity Study

  Herein we describe a molecular portrait of potentially curable, Gleason 7 and intermediate risk prostate cancer based on genome-wide CNV profiles of 96 patients, and subsequent whole-genome sequencing of 28 tumours from 10 patients, using DNA quantities that are achievable in diagnostic biopsies (50 ng). We show that Gleason 7 cancer is highly heterogeneous at the SNV, CNV, and intra-chromosomal translocation levels, and is characterized by a very low number of recurrent SNVs but significant structural variation. We identified a novel recurrent MYCL1 amplification, which was strongly associated with TP53 deletion and prognostic for biochemical recurrence in this cohort. Moreover, we identified clear evidence of divergent tumour evolution in multi focal cancer and, in 2/5 cases evaluated, multiple tumours of independent clonal origin. Taken together, these data represent the first systematic evaluation of the differential genomics of potentially curable prostate cancer, and strongly suggest that a more robust understanding of the relationship between genetic heterogeneity and clinical outcomes is required to effectively develop biomarkers of prognosis based on tumour genomics.

  Study EGAS00001000549

• Uveal melanoma patient with germline MBD4 nonsense mutation

  There is currently no effective treatment for metastasised uveal melanoma (UM). Recently, it was reported that a UM patient was responsive to checkpoint inhibitor (CI) treatment, due to a high tumour mutation burden correlated with a germline loss-of-function MBD4 mutation. Here, we report on another UM patient who carried an MBD4 germline nonsense variant (p.Leu563Ter) and her tumour showed a 5-fold higher than average mutation burden. We confirmed the association between germline loss-of-function variant in MBD4 and CI response. The patient experienced stable disease (10 months) and survived two years with metastatic disease, which is twice as long as median survival. Additionally, the frequency of MBD4 loss-of-function variants in reported UM cohorts was >20 times higher than in an aggregated population genome database (P < 5x10-5), implying a potential role as UM predisposition gene. These findings provide a strong basis for the inclusion of MBD4 in screening of potential UM-prone families as well as stratification of immunotherapy.

  Study EGAS00001003362

• MED12L Gene Alterations Define Aggressive BRCA2-Mutant Prostate Cancers

  Germline mutation of BRCA2 increases the lifetime risk of developing prostate cancer (PCa) by over 700%. BRCA2-mutant PCa have poorer prognosis than sporadic PCa, with rapid development of metastatic, castrate-resistant prostate cancer (mCRPC) and 5-year cancer-specific survival rates of ~50-60%1-4. Despite this, unique genomic driver events that explain the aggressiveness of localized BRCA2-mutant PCa are lacking. We used whole-genome sequencing to fully characterize 14 BRCA2-mutant PCa and demonstrate that BRCA2-mutant PCa is associated with increased genetic instability and a mutually exclusive mutational burden when compared to sporadic PCa. Importantly, BRCA2-mutated cancers are defined by unique copy number gains and hypomethylation events, including alterations in the MED12L/MED12 axis, which are found solely in mCRPC and are enriched in PCa tumours harbouring aggressive intraductal carcinoma (IDC-P) pathologic sub-types. Our findings begin to explain the clinical entity of BRCA2-mutated PCa as these tumours have a unique and aggressive genotype de novo, associated with IDC-P and mCRPC, even in the hormone-naive setting.

  Study EGAS00001001615