14478 results for "PLOS+ONE+Pennsylvania+German+ACS+language+code+pdc+open+access+study"

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• Engineering of a promoterless anti-viral RNAi hairpin into an endogenous miRNA locus

  Short hairpin RNA (shRNA) expression strategies that allow safe and persistent target mRNA knockdown are key to the success of many in vitro or in vivo RNAi applications. Here, we propose a novel solution which is expression of a promoterless miRNA-adapted shRNA (shmiRNA) from an engineered genomic miRNA locus. For proof-of-concept, we genetically “vaccinated” liver cells against a human pathogen, by using TALEns or CRISPR to integrate an anti-hepatitis C virus (HCV) shmiRNA into the liver-specific miR-122/hcr gene. Reporter assays and qRT-PCR confirmed anti-HCV shmiRNA expression as well as miR-122 integrity and functionality. Specificity and safety of shmiRNA integration were validated via PCR, cDNA and miRNA profiling, and whole genome sequencing. A subgenomic HCV replicon and a full-length reporter virus, but not a Dengue virus control, were significantly impaired in the modified cells. Our original combination of DNA engineering and RNAi expression technologies should benefit numerous applications, from basic miRNA research, to human cell and gene therapy.

  Study EGAS00001001252

• ALPI deficiency causes refractory Inflammation Bowel Disease

  Herein, we report the first identification of biallelic-inherited mutations in ALPI as a Mendelian cause of inflammatory bowel disease in two unrelated patients. ALPI encodes for intestinal phosphatase alkaline, a brush border metalloenzyme that hydrolyses phosphate from the lipid A moiety of lipopolysaccharides and thereby drastically reduces Toll-like receptor 4 agonist activity. Prediction tools and structural modelling indicate that all mutations affect critical residues or inter-subunit interactions, and heterologous expression in HEK293T cells demonstrated that all ALPI mutations were loss of function. ALPI mutations impaired either stability or catalytic activity of ALPI and rendered it unable to detoxify lipopolysaccharide-dependent signalling. Furthermore, ALPI expression was reduced in patients' biopsies, and ALPI activity was undetectable in ALPI-deficient patient's stool. Our findings highlight the crucial role of ALPI in regulating host-microbiota interactions and restraining host inflammatory responses. These results indicate that ALPI mutations should be included in screening for monogenic causes of inflammatory bowel diseases and lay the groundwork for ALPI-based treatments in intestinal inflammatory disorders.

  Study EGAS00001003350

• Integrated genomic analyses identify ARID1A and ARID1B alterations in the childhood cancer neuroblastoma

  Neuroblastomas are tumors of peripheral sympathetic neurons and are the most common solid tumor in children. To determine the genetic basis for neuroblastoma we performed whole-genome sequencing (6 cases), exome sequencing (16 cases), genome-wide rearrangement analyses (32 cases), and targeted analyses of specific genomic loci (40 cases) using massively parallel sequencing. On average each tumor had 19 somatic alterations in coding genes (range, 3-70). Among genes not previously known to be involved in neuroblastoma, chromosomal deletions and sequence alterations of chromatin remodeling genes, ARID1A and ARID1B, were identified in 8 of 71 tumors (11%) and were associated with early treatment failure and decreased survival. Using tumor-specific structural alterations, we developed an approach to identify rearranged DNA fragments in sera, providing personalized biomarkers for minimal residual disease detection and monitoring. These results highlight dysregulation of chromatin remodeling in pediatric tumorigenesis and provide new approaches for the management of neuroblastoma patients.Data Provider: Johns Hopkins Sidney Kimmel Comprehensive Cancer Center (SKCCC)

  Study EGAS00001000369

• Genome-wide SNP genotyping of Central African rainforest hunter-gatherers and neighbouring agriculturalists

  The emergence of agriculture in West-Central Africa, ~5,000 years ago, profoundly modified the cultural landscape and mode of subsistence of most sub-Saharan populations. How this major innovation has impacted the genetic history of rainforest hunter-gatherers — historically referred to as “pygmies” — and agriculturalists, however, remains poorly understood. Here, we report genome-wide SNP data from eight of these populations located west-to-east of the equatorial rainforest. We find that hunter-gathering populations present up to 50% of farmer genomic ancestry, and that substantial admixture began only within the last 1,000 years. Furthermore, we show that the historical population sizes characterising these communities already differed before the introduction of agriculture. Our results suggest that the first socio-economic interactions between rainforest hunter-gatherers and farmers introduced by the spread of farming were not accompanied by immediate, extensive genetic exchanges and occurred on a backdrop of two groups already differentiated by their specialisation in two ecotopes with differing carrying capacities.

  Study EGAS00001000605

• Multi-omics analysis defines core genomic alterations in pheochromocytomas and paragangliomas

  Pheochromocytomas (PCC) and paragangliomas (PGL) are neural crest-derived tumors. We performed the integrated genomic analysis of a collection of PCC/PGL from the French COMETE network using SNP arrays, whole-exome sequencing, DNA methylation arrays, mRNA expression arrays and miRNA sequencing. We found that PCC/PGL are characterized by a low mutation rate, with few recurrent somatic mutations and focal copy number alterations (CNAs). In contrast, we detected recurrent broad CNAs strongly associated with known molecular groups, often leading to the biallelic inactivation of the known susceptibility genes of PCC/PGL. We also identified DNA methylation changes and miRNA expression clusters strongly associated with molecular groups. Of note, overexpression of the miRNA cluster 182/96/183 is specific of SDHB-mutated tumors and induces invasive traits, whereas silencing of the imprinted DLK1-MEG3 miRNA cluster due to a loss of heterozygosity of the 14q32.2 locus is a potential driver in a subset of sporadic tumors. This comprehensive analysis illustrates the functional interdependence between genomic and epigenomic dysregulations underlying PCC/PGL.

  Study EGAS00001000933

• 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

• BLUEPRINT DNA methylation profiles of graft donors in allogenic hematopoietic stem cell transplantation

  Allogenic hematopoietic stem cell transplantation (HSCT) is a curative treatment for many hematological conditions. Acute graft-versus-host disease (aGVHD) is a prevalent immune-mediated complication following HSCT. Current diagnostic biomarkers that correlate with aGVHD severity, progression, and therapy response in graft recipients are insufficient. We investigated whether epigenetic marks measured in peripheral blood of healthy graft donors stratify aGVHD severity in HLA-matched sibling recipients prior to HSCT. We measured genome-wide DNA methylation levels in peripheral blood of 91 HSCT donors using Illumina Infinium HumanMethylation450 BeadChips. We showed that epigenetic signatures underlying aGVHD severity in recipients correspond to immune pathways relevant to aGVHD etiology. We identified distinct DNA methylation marks in graft donors that are associated with aGVHD severity status in recipients. Together, our findings suggest that ‘epigenetic matching’ of HSCT donor-recipient pairs in a clinical setting may be used in conjunction with genetic matching to inform both donor selection and transplantation strategy, with the ultimate aim of improving patient outcome.

  Study EGAS00001001287

• Genotype and exome data for an Australian Aboriginal population: a reference panel for health-based research

  Genetic analyses, including genome-wide association studies and whole exome sequencing (WES), provide powerful tools for the analysis of complex and rare genetic diseases. To date there are no reference data for Aboriginal Australians to underpin the translation of health-based genomic research. Here we provide a catalog of variants called after sequencing the exomes of 72 Aboriginal individuals to a depth of 20X coverage in 80% of the sequenced nucleotides. We determined 320,976 single nucleotide variants (SNVs) and 47,313 insertions/deletions using the Genome Analysis Toolkit. We had previously genotyped a subset of the Aboriginal individuals (70/72) using the Illumina Omni2.5 BeadChip platform and found 99% concordance at overlapping sites, which suggests high quality genotyping. Finally, we compared our SNVs to six publicly available variant databases, such as dbSNP and the Exome Sequencing Project, and 70,115 of our SNVs did not overlap any of the single nucleotide polymorphic sites in all the databases. Our data set provides a useful reference point for genomic studies on Aboriginal Australians.

  Study EGAS00001001585

• Whole-Exome Sequencing of Salivary Gland Mucoepidermoid Carcinoma

  Mucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy. To explore the genetic origins of MEC, we performed systematic genomic analyses of these tumors.Experimental DesignWhole-exome sequencing and gene copy number analyses were performed for 18 primary cancers with matched normal tissue. Fluorescence in situ hybridization (FISH) was used to determine the presence or absence of the MECT1-MAML2 translocation in 17 tumors.ResultsTP53 was the most commonly mutated gene in MEC (28%), and mutations were found only in intermediate- and high-grade tumors. Tumors with TP53 mutations had more mutations overall than tumors without TP53 mutations (p=0.006). POU6F2 was the second most frequently mutated gene, found in three low-grade MECs with the same in-frame deletion. Somatic alterations in IRAK1, MAP3K9, ITGAL, ERBB4, OTOGL, KMT2C, and OBSCN were identified in at least two of the 18 tumors sequenced. FISH analysis confirmed the presence of the MECT1-MAML2 translocation in 15 of 17 tumors (88%).ConclusionsThrough these integrated genomic analyses, MECT1-MAML2 translocation and somatic TP53 and POU6F2 mutations appear to be the main drivers of mucoepidermoid carcinoma.

  Study EGAS00001002811

• Whole exome sequencing of longitudinal samples from a melanoma patient receiving MEK plus CDK4/6 inhibitor therapy.

  Combined MEK and CDK4/6 inhibition (MEKi+CDK4i) has shown promising clinical outcomes in NRAS mutant melanoma patients. Here, we interrogated longitudinal biopsies from a patient who initially responded to MEKi+CDK4i therapy but subsequently developed resistance. Whole exome sequencing and functional validation identified an acquired PIK3CAE545K mutation as conferring drug resistance. We demonstrate that PIK3CAE545K pre-existed in a rare subpopulation that was missed by both clinical and research testing, but was revealed upon multi-region sampling due to PIK3CAE545K being non-uniformly distributed. This resistant population rapidly expanded after the initiation of MEKi+CDK4i therapy and persisted in all successive samples even after immune checkpoint therapy and distant metastasis. Functional studies identified activated S6K1 as both a key marker and specific therapeutic vulnerability downstream of PIK3CAE545K-induced resistance. These results demonstrate that comprehensive analysis of pre-treatment samples can reveal rare pre-existing resistant subpopulations and also posit S6K1 as a common downstream therapeutic nexus for the MAPK, CDK4/6, and PI3K pathways.

  Study EGAS00001002846