14477 results for "PLOS+ONE+Pennsylvania+German+ACS+language+code+pdc+open+access+study"

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• Epigenomic priming of immune genes implicates oligodendroglia in multiple sclerosissusceptibility

  Multiple sclerosis (MS) is characterized by a targeted attack on oligodendroglia (OLG)and associated myelin by immune cells, which are thought to be the main drivers of MS susceptibility. Assessing chromatin accessibility and the transcriptome simultaneously at the single cell level, we found that immune genes exhibit a primedchromatin state in mouse and human OLG in a non-disease context, compatible withrapid transitions to immune-competent states in MS. We identified transcription factors as BACH1 and STAT1 involved in immune gene regulation in oligodendrocyteprecursor cells (OPCs). A subset of immune genes present bivalency of H3K4me3/H3K27me3 in OPCs, with Polycomb inhibition leading to their increased activation upon interferon-gamma (IFNg) treatment. Some MS susceptibility single-nucleotide polymorphisms (SNPs) overlap with these regulatory regions in mouse andhuman OLG, and treatment of mouse OPCs with IFNg leads to chromatin architecture remodeling at these loci and altered expression of interacting genes. Our data indicates that susceptibility for MS may involve OLG, which therefore constitute novel targets for immunological-based therapies for MS.

  Study EGAS00001005911

• Genomic and functional fidelity of small cell lung cancer patient-derived xenografts

  Small cell lung cancer (SCLC) patient-derived xenografts (PDXs) can be generated from biopsies or circulating tumor cells (CTCs), though scarcity of tissue and low efficiency of tumor growth have previously limited these approaches. Applying an established clinical-translational pipeline for tissue collection and an automated microfluidic platform for CTC-enrichment, we generated 17 biopsy-derived PDXs and 17 CTC-derived PDXs in a two-year timeframe, at efficiencies of 89% and 38%, respectively. Whole exome sequencing showed that somatic alterations are stably maintained between patient tumors and PDXs. Early-passage PDXs maintain the genomic and transcriptional profiles of the founder PDX. In vivo treatment with etoposide and cisplatin (EP) in 30 PDX models demonstrated greater sensitivity in PDXs from EP naïve patients, and resistance to EP corresponded to increased expression of a MYC gene signature. Finally, serial CTC-derived PDXs generated from an individual patient at multiple time points accurately recapitulated the evolving drug sensitivities of that patient’s disease. Collectively, this work highlights the translational potential of this strategy.

  Study EGAS00001002853

• Tumor-intrinsic expression of the autophagy gene Atg16l1 suppresses anti-tumor immunity in colorectal cancer

  The vast majority of colorectal cancer (CRC) patients fail to respond to immune checkpoint inhibitors (ICI). Understanding tumor-intrinsic determinants of immunotherapy resistance is critical to improve CRC patient outcomes. Here, we demonstrate that transcript levels of the core autophagy gene ATG16L1 are prognostic of poor outcome and predictive of ICI resistance in late-stage CRC. Deletion of Atg16l1 in murine CRC organoids markedly inhibited tumor growth in primary and metastatic niches in syngeneic hosts. ATG16L1 deficiency rendered CRC organoids more responsive to interferon (IFN) signaling and enhanced programmed cell death while decreasing tumor stem-like populations. IFN hypersensitivity consequently promoted cytotoxic anti-tumor immunity in vivo. In IMblaze370, a large phase III clinical trial of anti-PD-L1 in advanced metastatic CRC, low ATG16L1 levels identified patients with increased lymphocyte infiltration and improved outcome in a KRAS mutant setting. This work reveals autophagy as a clinically relevant immunosuppressive mechanism in CRC and provides a rationale for autophagy inhibition to boost immunotherapy responses in the clinic.

  Study EGAS00001005952

• Exome sequencing demonstrates a dual origin of relapses in retinoic-acid resistant acute promyelocytic leukemia.

  Retinoic acid (RA) and arsenic target the PML/RARA driver of Acute Promyelocytic Leukemia (APL), their combination now curing over 95% patients. Here we report exome sequencing of 64 matched diagnosis/remission/relapses patients treated with historical RA/chemotherapy protocols. A first subgroup presents a high incidence of oncogenic mutations disrupting key epigenetic or transcriptional regulators (primarily WT1) or activating MAPK signaling at diagnosis. Relapses retain these cooperating oncogenes and exhibit additional oncogenic alterations and/or mutations impeding therapy response (RARA, NT5C2). The second group primarily exhibits FLT3 activation at diagnosis, which is lost upon relapse together with most other passenger mutations, implying that relapses derive from pre-leukemic PML/RARA-expressing cells that survived RA/chemotherapy. Accordingly, clonogenic activity of PML/RARA-immortalized progenitors ex vivo is only transiently affected by RA, but selectively abrogated by arsenic. Our studies stress the role of cooperating oncogenes in direct relapses and suggest that targeting pre-leukemic cells by arsenic contributes to its clinical efficacy.

  Study EGAS00001002893

• Somatic_mutation_profiling_of_intestinal_crypts_from_IBD

  In this project we want to investigate the role that somatic mutations in intestinal stem cells play in IBD. We will use laser capture microdissection to ascertain epithelial cells from an individual crypts/vilus. We will extract DNA from these and use a new low-input material library prep methods to make accurate libraries for sequencing. In this pilot phase of the project we will perform 15X whole-genome sequencing of a small number of crypts biopsied from four patients. Biopsies have been taken from inflammed and noninflammed patches to compare mutation rates and mutational signatures. We will also test if crypts from inflammed patches of a single patient are clonal (either within a given inflammed patch or across inflammed patches). We will quantify the rate of cancer driver mutations in inflammed and non-inflammed crypts. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/

  Study EGAS00001002896

• Mapping the breast cancer metastatic cascade onto circulating tumour DNA using genetic and epigenetic clonal tracking

  Circulating tumour DNA (ctDNA) allows tracking the evolution of human cancers at high resolution, overcoming many limitations of tissue biopsies. However, exploiting ctDNA to determine how a patient’s cancer is evolving in order to aid clinical decisions remains difficult. This is because ctDNA is a mix of fragmented alleles, and the contribution of different cancer cell subpopulations from distinct lesions to ctDNA remains largely unknown. Profiling of ctDNA almost invariably requires prior knowledge of what genomic alterations to track. Here we leverage on a rapid autopsy programme to demonstrate that unbiased genomic characterisation of several metastatic sites and concomitant ctDNA profiling at whole-genome resolution reveals the extent to which ctDNA is representative of widespread disease. We also present a ctDNA methylation profiling method that allows tracking evolutionary changes in the cancer cell population at single-molecule resolution without prior knowledge. These results have critical implications for the use of liquid biopsies to monitor cancer evolution in humans and potentially guide treatment.

  Study EGAS00001004014

• HCA_Placenta_Adult_Vento_RNA

  The Human Cell Atlas initiative is an ambitious global research effort which aims to describe every cell in the human body across all developmental stages to generate a reference map to accelerate progress in science and medicine particularly relating to human development and disease. The initiative is led by investigators based at the Wellcome Sanger Institute and the Broad Institute of MIT and Harvard and funding support from the Wellcome and NIH. This specific project will assess human development. We aim to interrogate the cellular composition and molecular regulators underpinning development and maturation through single cell RNA-sequencing/spatial transcriptomics and computational algorithms to predict cellular developmental trajectories and cell-cell interactions. We will subsequent validate these findings in situ using allied imaging technologies e.g. immunohistochemistry and RNAscope and in vitro culture of human intestinal organoids (HIOs). This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/

  Study EGAS00001004069

• Comprehensive pharmacogenomic characterization of gastric cancer

  Gastric cancer is among the most lethal human malignancies. Previous studies have identified molecular aberrations that constitute dynamic biological networks and genomic complexities of gastric tumors. However, the clinical translation of molecular-guided targeted therapy is hampered by challenges. Notably, solid tumors often harbor multiple genetic alterations, complicating the development of effective treatments. To address such challenges, we established a comprehensive dataset of molecularly annotated patient derivatives coupled with pharmacological profiles for 60 targeted agents to explore dynamic pharmacogenomic interactions in gastric cancers. We identified lineage-specific drug sensitivities based on histopathological and molecular subclassification, including substantial sensitivities toward VEGFR and EGFR inhibition therapies in diffuse- and signet ring-type gastric tumors, respectively. We identified potential therapeutic opportunities for WNT pathway inhibitors in ALK-mutant tumors, a significant association between PIK3CA-E542K mutation and AZD5363 response, and transcriptome expression of RNF11 as a potential predictor of response to gefitinib. Collectively, our results demonstrate the feasibility of drug screening combined with tumor molecular characterization to facilitate personalized therapeutic regimens for gastric tumors.

  Study EGAS00001004106

• Ovarian cancer organoid biobank

  Ovarian cancer (OC) is a heterogeneous disease usually diagnosed at a late stage. Experimental in vitro models that faithfully capture the hallmarks and tumor heterogeneity of OC are limited and hard to establish. We present a novel protocol that enables efficient derivation and long-term expansion of OC organoids. Utilizing this protocol, we have established 56 organoid lines from 32 patients, representing the spectrum of ovarian neoplasms, including non-malignant borderline tumors, as well as mucinous, clear-cell, endometrioid, low- and high-grade serous carcinomas. OC organoids recapitulate histological and genomic features of the pertinent lesion from which they were derived, illustrating intra- and inter-patient heterogeneity, and can be genetically modified. We show that OC organoids can be used for drug screening assays and capture different tumor subtype responses to the gold standard platinum-based chemotherapy, including acquisition of chemoresistance in recurrent disease. Finally, OC organoids can be xenografted, enabling in vivo drug sensitivity assays. Taken together, this demonstrates their potential application for research and personalized medicine.

  Study EGAS00001003073

• Cancer immune control needs senescence induction by Stat1 dependent cell cycle regulator pathways in tumours

  Immune checkpoint bloackade (ICB)-based or natural cancer immune responses largely eliminate tumours. Yet, they require additional mechanisms to arrest those cancer cells that are not rejected. Cytokine-induced senescence (CIS) can stably arrest cancer cells, suggesting that interferon-dependent induction of senescence-inducing cell cycle regulators is needed to control those cancer cells that escape from killing. Here we report in two different cancers sensitive to T cell-mediated rejection, we show that deletion of the senescence-inducing cell cycle regulators p16Ink4a/p19Arf (Cdkn2a) or p21Cip1 (Cdkn1a) in the tumour cells abrogated both, the natural and the ICB-induced cancer immune control. Also in humans, melanoma metastases that progressed rapidly during ICB have losses of senescence-inducing genes and amplifications of senescence inhibitors. Metastatic cells also resist CIS. Such genetic and functional alterations are infrequent in metastatic melanomas regressing during ICB. Thus, activation of tumour-intrinsic, senescence-inducing cell cycle regulators is required to stably arrest those cancer cells that escape from eradication.

  Study EGAS00001004151