16484 results for "sec+and+unspecified+malignant+neoplasm"

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• Recursive splicing in long vertebrate genes

  Recent studies have shown that expression of many genes with exceptionally long introns in the mammalian brain can be perturbed by regulatory factors linked to neurodevelopmental or neurodegenerative disorders1-3, suggesting unique regulatory mechanisms. Here we identify functional recursive splice sites (RSS) in long introns of genes expressed in the brain. These RSS are highly conserved in genes with extreme length across diverse vertebrate species and permit step-wise removal of long introns via recursive splicing. Recursive splicing requires initial definition of a “recursive exon” that is located downstream of RSS, and most often contains premature stop codons. Moreover, we show that RSS create a splicing switch driven by splice site competition in order to distinguish primary mRNA isoforms from alternative isoforms that are prevalent in long genes. The recursive exon is not detectable in the dominant mRNA isoform due to recursive splicing, but is completely included when cryptic promoters or other cryptic exons are used. Thus, by coupling inclusion of recursive exons with the use of cryptic elements, RSS act to distinguish new mRNA isoforms emerging from long genes.

  Study EGAS00001001170

• 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

• An essential role for MYB in driving oncogenic EVI1 expression in enhancer-rearranged leukemias

  In acute myeloid leukemia (AML) with inv(3)(q21;q26) or t(3;3)(q21;q26), a translocated GATA2 enhancer drives oncogenic expression of EVI1. We generated an EVI1-GFP AML model and applied an unbiased CRISPR/Cas9 enhancer scan to uncover sequence motifs essential for EVI1 transcription. Using this approach, we pinpoint a single regulatory element in the translocated GATA2 enhancer that is critically required for aberrant EVI1 expression while being dispensable for GATA2 expression from its endogenous locus. This element contains a DNA binding motif for the transcription factor MYB that heavily occupies this site specifically at the translocated allele. MYB knockout as well as peptidomimetic blockade of p300-dependent MYB function resulted in downregulation of EVI1 but not of GATA2. Targeting MYB or mutating its DNA-binding motif within the GATA2 enhancer resulted in myeloid differentiation and cell death, suggesting that interference with MYB-driven EVI1 transcription provides a potential entry point for therapy of inv(3)/t(3;3) AMLs.

  Study EGAS00001004839

• Intratumoral plasma cells predict outcomes to PD-L1 blockade in non-small cell lung cancer

  Inhibitors of the programmed cell death-1 (PD-1/PD-L1) signaling axis are approved to treat non-small cell lung cancer (NSCLC) patients, based on their significant overall survival (OS) benefit. Using transcriptomic analysis of 891 NSCLC tumors from patients treated with either the PD-L1 inhibitor atezolizumab or chemotherapy from two large randomized clinical trials, we found a significant B cell association with extended OS with PD-L1 blockade, independent of CD8+ T cell signals. We then derived gene signatures corresponding to the dominant B cell subsets present in NSCLC from single-cell RNA-seq data. Importantly, we found increased plasma cell signatures to be predictive of OS in patients treated with atezolizumab, but not chemotherapy. B cells were also associated with the presence of tertiary lymphoid structures and organized lymphoid aggregates. Our results suggest an important contribution of B and plasma cells to PD-L1 blockade efficacy in NSCLC.

  Study EGAS00001005013

• An instructive role for IL7RA in the development of human B-cell precursor leukemia

  Kinase signaling fuels growth of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Yet its role in leukemia initiation is unclear and has not been shown in primary human hematopoietic cells. We previously described activating mutations in interleukin-7 receptor alpha (IL7RA) in poor-prognosis “ph-like” BCP-ALL. Here we show that expression of activated mutant IL7RA in human CD34+ hematopoietic cells creates a preleukemic state in transplanted NOD/LtSz-scid IL2Rγnull mice, characterized by persistence of self-renewing Pro-B cells with non-productive V(D)J gene rearrangements. Preleukemic CD34+CD10highCD19+ cells evolved to a BCP-ALL with spontaneously acquired CDKN2A deletions as commonly observed in primary human BCP-ALL. CRISPR mediated silencing of CDKN2A in primary human CD34+ cells transduced with activated IL7RA resulted in robust development of BCP-ALLs in-vivo. Thus, we demonstrate for the first time that constitutive activation of IL7RA can initiate preleukemia in primary human hematopoietic progenitors and cooperates with CDKN2A silencing in progression into BCP-ALL.

  Study EGAS00001005347

• RNA-seq of M-CSF differentiated human peripheral monocyte-derived macrophages (MDMs) - Validation macIDR

  Macrophages represent multifunctional leukocytes defined by their stimulus-specific transcriptional reprogramming. As in vivo macrophages are often difficult to obtain, in vitro macrophage models are often used. We aggregated public expression data to define consensus expression profiles for eight commonly-used in vitro macrophage models and built the classifier macIDR, capable of distinguishing macrophage subsets with high accuracy (>0.95). Classification of in vivo macrophages suggested that alveolar macrophages resembled interleukin-10 activated macrophages in general whereas chronic obstructive pulmonary disease patients displayed decreased similarity to interferon-γ stimulated macrophages. Adipose tissue-derived macrophages were classified as unstimulated macrophages, but would resemble LPS-stimulated macrophages more in diabetic-obese patients. Rheumatoid arthritic synovial macrophages were similar to macrophages stimulated with interleukin-10 or interferon-γ. Altogether, our results suggest that macIDR is capable of identifying in vitro macrophages. By projecting in vivo macrophages onto the in vitro macrophages, we were capable of elucidating macrophage-specific changes as a result of tissue and disease.

  Study EGAS00001003451

• Understanding_Self__Organising_Capacity_of_Stem_Cells_during_Implantation_and_Early_Post_implantation_Development_in_vitro_and_in_vivo__Implications_for_Human_Development_

  The aim of this project is to differentiate human embryonic stem cells to an extra-embryonic fate, specifically the hypoblast. This is of uttermost importance given the current lack of human hypoblast stem cells. We hypothesized that the pluripotent characteristics of the starting human embryonic stem cell population may dictate the competency for extra-embryonic cell fate specification. Based on this hypothesis and using human embryonic stem cells maintained in different naïve-like culture regimes, we have now developed conditions that allow the differentiation of human embryonic stem cells to a stable GATA6+ SOX2- population. This suggests that these cells may be putative human hypoblast stem cells. To validate this finding here we propose to perform RNA sequencing experiments of the differentiated human embryonic stem cells. By comparing their RNA expression profile to the single cell sequencing data of the human embryo that we are currently generating, we will be able to determine the identity of our GATA6+ SOX2- cells, and establish whether they represent the in vivo human hypoblast.

  Study EGAS00001003571

• Hofer et al., A specific subpopulation of cancer-associated fibroblasts promotes resistance to chemotherapy in triple-negative breast cancer by upregulating G0S2 protein

  Chemotherapy is the standard of care for patients with triple-negative breast cancer (TNBC), but the mechanisms of chemoresistance remain poorly understood. Here, we investigated the role of cancer associated fibroblasts (CAFs) in the chemotherapy response of TNBC, by combining in vivo analyses of TNBC patients with ex vivo cancer modeling, using tumor-on-chip (ToC) technology. Transcriptomic analysis revealed that the proportion of a specific CAF population, the extracellular matrix-producing myofibroblasts (ECM-myCAFs), is reduced after chemotherapy in chemo-sensitive, but not in chemo-resistant TNBC patients. In ToC devices, primary ECM-myCAFs promoted TNBC cell survival under Doxorubicin and Paclitaxel treatment. The mechanism of chemoresistance was elucidated by using single-cell RNA sequencing, advanced cell imaging and functional assays: ECM-myCAFs upregulate the G0/G1 switch 2 (G0S2) protein in TNBC cells, via activation of SRC family kinases. Altogether, our work identifies G0S2 as a new player in CAF mediated chemotherapy resistance in TNBC.

  Study EGAS50000000886

• Multidimensional and Longitudinal Immune Profiling of Sepsis in Uganda

  We conducted a prospective, observational cohort study of adults (RESERVE-U-2-TOR) admitted to Tororo General Hospital in eastern Uganda with severe, undifferentiated infection (i.e., suspected sepsis). Briefly, whole-blood samples were collected in PAXgene blood RNA tubes (PreAnalytiX, Qiagen, Germantown, MD, USA), from which RNA was extracted using PAXgene Blood RNA Kits (cat. no. 762164) (Qiagen). Sequencing libraries were constructed with the NEBNext Ultra II RNA Library Preparation Kit for Illumina, after which libraries were multiplexed and sequenced on the Illumina NovaSeq X Plus platform (Illumina, Inc, San Diego, CA). Data from this study available through dbGaP include raw RNA-Seq data generated from whole-blood samples collected upon RESERVE-U-2-TOR study enrollment (N=274).

  Study phs003914

• Targeting PTPRK-RSPO3 colon tumours promotesdifferentiation and loss of stem-cell function

  Colorectal cancer remains a major unmet medical need, promptinglarge-scale genomics efforts in the field to identify moleculardrivers for which targeted therapies might be developed. Wepreviously reported the identification of recurrent translocationsin R-spondin proteins present in a subset of colorectal tumours.Here we show that targeting RSPO3 in PTPRK-RSPO3-fusion positivehuman tumour xenografts inhibits tumour growth andpromotes differentiation. Notably, genes expressed in the stem-cellcompartment of the intestine were among those most sensitive toanti-RSPO3 treatment. This observation, combined with functionalassays, suggests that a stem-cell compartment drives PTPRK-RSPO3colorectal tumour growth and indicates that the therapeutictargeting of stem-cell properties within tumours may be a clinicallyrelevant approach for the treatment of colorectal tumors.

  Study EGAS00001001462