16577 results for "sec+and+unspecified+malignant+neoplasm"

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• Myelodysplastic cells in patients re-program mesenchymal stromal cells to establish a transplantable stem cell-niche disease unit.

  Myelodysplastic syndromes (MDS) are a heterogeneous group of myeloid neoplasms with defects in hematopoietic stem/progenitor cells (HSPCs) and possibly the HSPC niche. Here we show that patient-derived mesenchymal stromal cells (MDS MSCs) display a disturbed differentiation program and are essential for the propagation of MDS-initiating lin-CD34+CD38- stem cells in orthotopic xenografts. Overproduction of niche factors such as N-Cadherin, IGFBP2, VEGFA and LIF is associated with the ability of MDS MSCs to enhance MDS expansion. These factors represent putative therapeutic targets to disrupt critical hematopoietic-stromal interactions in MDS. Finally, healthy MSCs adopt "MDS-MSC like" molecular features when exposed to hematopoietic MDS cells, indicative of an instructive remodeling of their microenvironment. This patient-derived xenograft model therefore provides functional and molecular evidence that MDS is a complex disease involving both the hematopoietic and stromal compartments. The resulting deregulated expression of niche factors may well also be a feature of other hematopoietic malignancies.

  Study EGAS00001000716

• ChIP-seq of plasma cell-free nucleosomes identifies gene expression programs of the cells-of-origin

  Cell-free DNA in human plasma provides access to molecular information about the pathological processes in the organs or tumors from which it originates. These DNA fragments are derived from fragmented chromatin in dying cells, and retain some of the cell of origin histone modifications. Here, we apply chromatin immunoprecipitation of cell-free nucleosomes carrying active chromatin modifications followed by sequencing (cfChIP-seq) to 268 human samples. In healthy donors, we identified bone marrow megakaryocytes, but not erythroblasts, as major contributors to the cfDNA pool. In patients with a range of liver diseases, we show that we can identify pathology-related changes in hepatocyte transcriptional programs. In metastatic colorectal carcinoma patients, we detected clinically relevant, and patient-specific information, including transcriptionally active HER2 amplifications. Altogether, cfChIP-seq using low sequencing depth, provides systemic and genome-wide information, can inform diagnosis, and facilitate interrogation of physiological and pathological processes using blood samples.

  Study EGAS00001004913

• Whole_genome_sequencing_in_a_multiplex_Crohn_s_disease_family

  In 2009 we identified a four-generation family with over 700 members and 41 affected with Crohn's disease (CD). At the time we sequenced the exome of 6 affected individuals but did not identify any coding variants which appear to explain the high prevalence of disease. Since then we have collected DNA from a large number of additional family members, genotyped linkage arrays on the entire family to refine genomic regions shared by identity by descent and genotyped affected and unaffected members at known CD risk loci identified by Genome Wide Association Studies (GWAS). These analyses have confirmed that a significant unexplained excess of disease remains after accounting for all known genetic factors, and that several regions of the genome are shared by a large fraction of affected individuals. We therefore perform whole genomes sequencing from 8 individuals which will allow us to impute the complete sequence of nearly all the members of the two largest and most severely affected branches of the family.

  Study EGAS00001000060

• single cell sequencing of resting and Influenza-stimulated mononcluear phagocytes of African and Europeans with varying degree of ex-vivo susceptibility to Influenza

  There is considerable inter-individual immunological and clinical variability upon influenza A virus (IAV) infection in humans; yet, the factors underlying such heterogeneity remain elusive. Here, using an ex vivo cellular model that captures natural variation in the transcriptional responses of monocytes to IAV, we find significant differences in viral mRNA levels between individuals of African and European ancestry. Using single cell analyses, we show that the overall number of cells that will ultimately become infected, rather than the amount of viral transcript expression per cell, is the main driver of the surprisingly higher IAV mRNA levels detected in European cells. Finally, we identify 135 genes, including the interferon-stimulated genes IFITM3, MX1, and OAS3, for which basal mRNA expression levels associate with IAV mRNA levels post infection. Our findings reveal that basal differences in activation of IRF/STAT-induced antiviral mechanisms may contribute to individual and population disparities in susceptibility to IAV infection.

  Study EGAS00001005000

• Mapping the human hematopoietic stem and progenitor cell hierarchy through integrated single-cell proteomics and transcriptomics

  Single-cell transcriptomics (scRNA-seq) has enabled the characterization of cell state heterogeneity and recapitulation of differentiation trajectories. However, since proteins are the main functional entities in cells, the exclusive use of mRNA measurements comes at the risk of missing important biological information. Here we leverage recent technological advances in single-cell proteomics by Mass Spectrometry (scp-MS) to generate the first scp-MS dataset of an in vivo differentiation hierarchy encompassing over 2,500 human CD34+ hematopoietic stem and progenitor cells. Through integration with scRNA-seq, we identify proteins that are important for stem cell quiescence, which were not indicated by their mRNA transcripts, and demonstrate functional expression covariance during differentiation that is only detectable on protein level. Finally, we show that modeling translation dynamics can infer cell progression during differentiation and explain 45% more protein variation from mRNA than linear correlation. Our work serves as a framework for future single-cell multi-omics studies across biological systems.

  Study EGAS00001007930

• Epigenomic alterations define lethal CIMP-positive ependymomas of infancy

  Ependymomas are common childhood brain tumours that occur throughout the nervous system, but are most common in the paediatric hindbrain. Current standard therapy comprises surgery and radiation, but not cytotoxic chemotherapy as it does not further increase survival. Whole-genome and whole-exome sequencing of 47 hindbrain ependymomas reveals an extremely low mutation rate, and zero significant recurrent somatic single nucleotide variants. Although devoid of recurrent single nucleotide variants and focal copy number aberrations, poor-prognosis hindbrain ependymomas exhibit a CpG island methylator phenotype. Transcriptional silencing driven by CpG methylation converges exclusively on targets of the Polycomb repressive complex 2 which represses expression of differentiation genes through trimethylation of H3K27. CpG island methylator phenotype-positive hindbrain ependymomas are responsive to clinical drugs that target either DNA or H3K27 methylation both in vitro and in vivo. We conclude that epigenetic modifiers are the first rational therapeutic candidates for this deadly malignancy, which is epigenetically deregulated but genetically bland.

  Study EGAS00001000443

• Translation of non-canonical open reading frames as a cancer cell survival mechanism in childhood medulloblastoma

  A hallmark of high-risk childhood medulloblastoma is the dysregulation of RNA translation. Currently, it is unknown whether medulloblastoma dysregulates the translation of putatively oncogenic non-canonical open reading frames. To address this question, we performed ribosome profiling of 32 medulloblastoma tissues and cell lines and observed widespread non-canonical ORF translation. We then developed a step-wise approach to employ multiple CRISPR-Cas9 screens to elucidate functional non-canonical ORFs implicated in medulloblastoma cell survival. We determined that multiple lncRNA-ORFs and upstream open reading frames (uORFs) exhibited selective functionality independent of the main coding sequence. One of these, ASNSD1-uORF or ASDURF, was upregulated, associated with the MYC family oncogenes, and was required for medulloblastoma cell survival through engagement with the prefoldin-like chaperone complex. Our findings underscore the fundamental importance of non-canonical ORF translation in medulloblastoma and provide a rationale to include these ORFs in future cancer genomics studies seeking to define new cancer targets.

  Study EGAS00001007426

• Genomic data from analysis of the human placenta, part of the Pregnancy Outcome Prediction study (POPs)

  The Pregnancy Outcome Prediction (POP) study is a prospective cohort study of nulliparous women attending the Rosie Hospital (Cambridge, UK) for their dating ultrasound scan. The study included 4512 women with a viable singleton pregnancy; study participants provided written informed consent and were recruited between January 2008 and July 2012. The POP study aimed both at evaluating performance of known biomarkers and serial ultrasonography in assessing maternal and fetal well-being, as well as identifying novel biomarkers. The study is sufficiently large to be powered for relatively uncommon adverse pregnancy outcomes. Women attended four study visits scheduled every 8 weeks, starting with the first trimester. Participants had blood taken during the dating/recruitment visit (at approximately 12 weeks gestation (wkGA)), as well as at three subsequent visits (at ∼20wkGA, ∼28wkGA and ∼36wkGA). For more detail, please visit: https://www.obgyn.cam.ac.uk/research/pops-2/.

  Study EGAS00001002205

• A novel subset of human CD33+ haematopoietic stem cells characterized at single-cell resolution

  Elucidation of the identity and diversity of mechanisms that sustain long-term human blood cell production remains an important challenge. Previous studies indicate that, in adult mice, this property is ultimately vested in cells uniquely identified by their ability to clonally regenerate detectable levels of mature blood cells in serially transplanted recipients. We now present a combined multi-parameter analysis of the molecular features of very primitive human cord blood cells that display different cell output activities in vitro and in vivo. These analyses identified a new, prospectively separable, but still functionally heterogeneous, subset of long-term human blood-forming cells. Single-cell measurements of their transcriptional, DNA methylation and 40-protein content and of closely related phenotypes revealed numerous subtle, but consistent differences both within and between each subset analyzed. These results suggest that multiple regulatory mechanisms underlie the functional heterogeneity exhibited by clonally tracked human blood cell precursors with long-term output abilities.

  Study EGAS00001002826

• Somatic_mutation_and_clonal_evolution_normal_breast_tissue_TGS

  Cancer is a genetic disease caused by an accumulation of mutations, however many of these mutations have been identified in pathologically normal tissue. We aim to use laser-capture microscopy (LCM) to sample individual clones from breast tissue to identify whether cancer-associated mutations appear in this normal tissue, assess the mutational burden present, and identify the mutational processes causing these mutations. We will sample from a wide age range of individuals (<20 to >70 years old) to determine whether these processes differ in pre- and post-menopausal women. We will also be comparing the tissue from healthy individuals (samples from breast reduction surgery) to those at elevated risk of breast cancer (mastectomy from BRCA1/2 patients) and those who have breast cancer (adjacent normal, distal normal, and tumour tissue from mastectomy). This will allow us to determine how these processes are different between these groups of individuals, and gain insight into the earliest stages of tumour development.

  Study EGAS00001002858