14480 results for "PLOS+ONE+Pennsylvania+German+ACS+language+code+pdc+open+access+study"

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• DEPArray-based sorting of pure carcinoma and stromal populations from formalin-fixed paraffin-embedded (FFPE) tissues followed by shallow whole genome sequencing

  To overcome the challenges of low DNA yields, degraded DNA by formalin fixation and diluted signal of genomic aberrations by non-carcinoma components in the heterogeneous FFPE samples, we isolated pure carcinoma and stromal cells using the DEPArray™ NxT system, a microchip-based digital sorter that allows isolation of pure, homogeneous subpopulations of cells from FFPE samples. We isolated pure carcinoma and stromal cell populations from 12 FFPE tissues, including tissues from 9 primary and metastatic breast cancer and 3 primary ovarian high-grade serous carcinomas. This was followed by downstream shallow whole genome sequencing (WGS) for copy number landscape profiling for 10 samples. Seven out of 10 samples (even some with low tumour content or of old age) produced good quality genomic data, detecting sCNA in all carcinoma population samples but not in the stromal populations.

  Study EGAS50000001328

• Co-culture experiment (hashed samples)

  The principles governing tissue architecture and the mechanisms underlying its disruption in disease remain poorly understood. Here, we utilized single-cell and spatial mapping to interrogate the mechanisms directing immune cell organization in human lymph nodes and its disruption in architecturally distinct lymphoma entities: indolent follicular lymphoma (FL) and aggressive diffuse large B cell lymphoma (DLBCL). Our data substantiate the central role of lymph node stromal cells in chemokine-driven lymphocyte zonation and reveal an inflammatory feedback loop fueled by tumor-reactive T cells, triggering stromal remodeling, progressive loss of homeostatic chemokine gradients and tissue organization from non-malignant to FL and DLBCL. Loss of homeostatic chemokines was associated with adverse patient survival, identifying the underlying architectural rearrangement as a key event during lymphomagenesis. Collectively, our results highlight the principles of lymph node organization and suggest how lymphoma-induced microenvironmental reprogramming drives loss of tissue organization.

  Study EGAS50000001252

• APOL1 Risk Variants Induce Metabolic Reprogramming of Podocytes in Patient-Derived Kidney Organoids

  Apolipoprotein L1 (APOL1) high-risk genotypes G1 and G2 are responsible for the increased risk of chronic kidney disease (CKD) in the African-American population, especially in the presence of interferon gamma (IFN-γ). Here, we applied single cell transcriptomics on kidney organoids generated from patient-derived induced pluripotent stem cells (iPSCs) to model human APOL1 nephropathy. iPSCs were generated from fibroblasts of two patients with APOL1 nephropathy homozygous for G1 or G2 risk variants, and an isogenic control (G0) was created by gene correction. Kidney organoids were generated according to previously published protocol (Takasato M et al. Nat. Protoc. 2016) and treated with IFN-γ for two days to induce APOL1. Twenty-four hours after IFN-γ removal, treated organoids from all three lines that were cultured in parallel were harvested for single cell transcriptomics.

  Study EGAS50000001223

• Frequent mutations in chromatin-remodelling genes in pulmonary carcinoids

  Pulmonary carcinoids are rare neuroendocrine tumours of the lung. The molecular alterations underlying the pathogenesis of these tumours have not been systematically studied so far. Here we perform gene copy number analysis (n¼54), genome/exome (n¼44) and transcriptome (n¼69) sequencing of pulmonary carcinoids and observe frequent mutations in chromatin-remodelling genes. Covalent histone modifiers and subunits of the SWI/SNF complex are mutated in 40 and 22.2% of the cases, respectively, with MEN1, PSIP1 and ARID1A being recurrently affected. In contrast to small-cell lung cancer and large-cell neuroendocrine tumours, TP53 and RB1 mutations are rare events, suggesting that pulmonary carcinoids are not early progenitor lesions of the highly aggressive lung neuroendocrine tumors but arise through independent cellular mechanisms. These data also suggest that inactivation of chromatinremodelling genes is sufficient to drive transformation in pulmonary carcinoids.

  Study EGAS00001000650

• An oncogenic enhancer-rearrangement causes concomitant deregulation of EVI1 and GATA2 in leukemia. Targeted resequencing of chromosomal regions centered on 3q21 and 3q26 in conjunction with RNA-Seq from Acute Myeloid Leukemia patients.

  Chromosomal rearrangements without gene-fusions have been implicated in leukemogenesis by causing deregulation of proto-oncogenes via relocation of cryptic regulatory DNA elements. AML with inv(3)/t(3;3) is associated with aberrant expression of the stem-cell regulator EVI1. Applying functional genomics and genome-engineering, we demonstrate that both 3q-rearrangements reposition a distal GATA2 enhancer to ectopically activate EVI1 and simultaneously confer GATA2 functional haploinsufficiency, previously identified as the cause of sporadic familial AML/MDS and MonoMac/Emberger syndromes. Genomic excision of the ectopic enhancer restored EVI1 silencing and led to growth inhibition and differentiation of AML cells, which could be replicated by pharmacologic BET-inhibition. Our data show that structural rearrangements involving chromosomal repositioning of enhancers can cause deregulation of two unrelated distal genes, with cancer as the outcome.

  Study EGAS00001000669

• Measuring the level of relatedness between NGS datasets

  Sequencing technologies are providing increasingly detailed insight in genetic makeup are paving their way into molecular diagnostics. The field will benefit from rigorous and bias-free measures for the quality of sequence data and for the proper representation of the complexity of the original samples. While current methodologies rely on the availability of a well-characterized reference genome, we propose kMer profiling for alignment-free assessment of the quality, comparability, and complexity of sequencing datasets. We show that kMer detects technical artefacts such as high duplication rates, library chimaeras, and differences in library preparation protocols in whole-genome, whole-exome, and RNA sequencing data. Additionally, it successfully captures the complexity and diversity of microbiomes. Thus, kMer allows for a robust evaluation of the quality and complexity of sequencing data without relying on any prior information and opens the way to a more reliable biological reasoning.

  Study EGAS00001000600

• Reconstructing the dispersals and adaptive history of Bantu-speaking populations in Africa and North America

  Bantu languages are spoken by ~310 million Africans, yet the genetic history of Bantu-speaking populations remains largely unexplored. We generated genomic data for 1,318 individuals from 35 populations in western central Africa, where Bantu languages originated. We found that early Bantu speakers first moved southward, through the equatorial rainforest, before spreading toward eastern and southern Africa. We also found that genetic adaptation of Bantu speakers was facilitated by admixture with autochthonous populations, particularly for the HLA and LCT loci. Finally, we identified a major contribution of western central African Bantu speakers to the ancestry of African Americans, whose genomes present no strong signals of natural selection. Together, these results highlight the contribution of Bantu-speaking peoples to the complex genetic history of Africans and African Americans.

  Study EGAS00001002078

• The impact of mutational clonality in predicting the response to anti-PD-L1/PD-L1 in advanced urothelial cancer

  The advent of immune checkpoint inhibitors (ICI) has radically changed the management and therapeutic treatment landscape for patients with cancer. It has been shown that the use of these inhibitors can result in long-term complete remissions even in cases with advanced stages of the disease. However, only a small fraction of patients respond to the treatment. A better understanding of which factors could drive this clinical benefit is fundamental to building more accurate predictive biomarkers and developing alternative therapeutic options for patients who are unlikely to benefit. In order to address this issue, we have generated and analyzed whole exome sequencing (WES) and RNA sequencing (RNASeq) data from a cohort of metastatic urothelial carcinoma patients (N = 27) treated with ICI such as anti-PD-(L)1 monoclonal antibodies.

  Study EGAS00001007086

• Tracing the origins of relapse in AML to stem cells

  In acute myeloid leukemia (AML), most patients relapse despite achieving remission. While relapse-specific mutations are sometimes detected at low frequency within bulk diagnosis samples, the cell type giving rise to relapse is unknown. Through combined genetic and functional analysis of purified subpopulations and xenografts from paired diagnosis/relapse samples, we identified two major patterns of relapse arising from therapy-resistant cells already present at diagnosis. In some cases relapse originated from rare leukemia stem cells with a primitive immunophenotype, while in other instances relapse developed from larger subclones of immunophenotypically-committed cells that retained strong stemness transcriptional signatures. The identification of distinct patterns of relapse should lead to improved methods for disease management and monitoring in AML. Moreover, the shared functional and transcriptional stemness properties that underlie both cellular origins of relapse underscore the importance of developing new therapeutic approaches that target stemness to prevent relapse.

  Study EGAS00001002225

• RNA stability controlled by m6A methylation contributes to X-to-autosome dosage compensation in mammals

  In mammals, X-chromosomal genes are expressed from a single copy since males (XY) possess a single X chromosome, while females (XX) undergo X inactivation. To compensate for this reduction in dosage compared to two active copies of autosomes, it has been proposed that genes from the active X chromosome exhibit dosage compensation. However, the existence and mechanism of X-to-autosome dosage compensation are still under debate. Here, we show that X-chromosomal transcripts are reduced in m6A modifications and more stable compared to their autosomal counterparts. Acute depletion of m6A selectively stabilises autosomal transcripts, resulting in perturbed dosage compensation in mouse embryonic stem cells. We propose that higher stability of X-chromosomal transcripts is directed by lower levels of m6A, indicating that mammalian dosage compensation is partly regulated by epitranscriptomic RNA modifications.

  Study EGAS00001007112