3773 results for "*oma"

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• Serial assessment of measurable residual disease in medulloblastoma liquid biopsies

  Nearly one-third of children with medulloblastoma, a malignant embryonal tumor of the cerebellum, succumb to their disease. Conventional response monitoring by imaging and cerebrospinal fluid (CSF) cytology remains challenging and a marker for measurable residual disease (MRD) is lacking. Here, we show the clinical utility of CSF-derived cell-free DNA (cfDNA) as a biomarker of MRD in serial samples collected from children with medulloblastoma (123 patients, 476 samples) enrolled on a prospective trial. Using low-coverage whole-genome sequencing, tumor-associated copy-number variations (CNVs) in CSF-derived cfDNA are investigated as an MRD surrogate. MRD is detected at baseline in 85% and 54% of patients with metastatic and localized disease, respectively. The number of MRD-positive patients decline with therapy, yet those with persistent MRD have significantly higher risk of progression. Importantly, MRD detection precedes radiographic progression in half who relapse. Our findings advocate for the prospective assessment of CSF-derived liquid biopsies in future trials for medulloblastoma.

  Study EGAS00001005592

• Aberrant ERBB4-SRC Signaling as a Hallmark of Group 4 Medulloblastoma Revealed by Integrative Phosphoproteomic Profiling

  The four main medulloblastoma subgroups are characterized by distinct biology, clinicopathological features and clinical outcomes. While the WNT and SHH subgroups are characterized by clearly defined aberrant signaling of developmental pathways, the underlying biology of Group 3 and 4 remains poorly understood. Here, we delineate distinct post-translational regulation orchestrating active oncogenic signaling networks in Groups 3 and 4. Specifically, aberrant ERBB4-SRC signaling constitutes a novel hallmark feature of Group 4, with great promise as a novel oncogenic mechanism and potential vulnerability for therapeutic intervention in the most common subgroup. Altogether, this novel integrative proteogenomic landscape demonstrates the added value of proteomics and phosphoproteomics analysis to discover and exploit unexpected oncogenic mechanisms in medulloblastoma and beyond.

  Study EGAS00001002757

• scRNA-seq of LN and lymphoma stroma

  The activities of non-haematopoietic cells (NHCs), including mesenchymal stromal cells and endothelial cells, in lymphomas, reportedly underlie lymphomagenesis. However, understanding of lymphoma NHCs has been hampered by unexplained NHC heterogeneity, even in normal human lymph nodes (LNs). Here, we constructed a single-cell transcriptome atlas of >100,000 NHCs collected from 27 human samples, including LNs and various nodal lymphomas, revealing 30 distinct subclusters, including some that were previously unrecognized. Notably, this atlas was highly useful for comparative analysis with lymphoma NHCs, which revealed an unanticipated landscape of subcluster-specific changes in gene expression and interaction with malignant cells in follicular lymphoma NHCs, facilitating our understanding of stromal remodelling in lymphoma and potentially suggesting novel biomarkers. Our study largely updates NHC taxonomy in human LNs and pertains to analysis of disease status, providing a rich resource and deeper insights into LN and lymphoma biology and offering to advance lymphoma management and therapy.

  Study EGAS00001005732

• Single-cell atlas of multiple myeloma and precursor diseases

  Single cell profiling of small cohorts of myeloma precursor disease patient samples including monoclonal gammopathy of unknown significance and smoldering multiple myeloma have shown diverse evolutionary patterns and immune changes that occur early in the disease process. Using scRNAseq and scBCRseq in a large cohort of fifty-three patients with myeloma precursor disease in comparison with myeloma and normal donors we describe the early genomic drivers of malignant transformation and describe their divergent clonal expansion in hyperdiploid compared to non-hyperdiploid samples. We describe intra-patient heterogeneity with potential therapeutic implications as well as the distinct evolution patterns (linear/branching) from myeloma precursor disease to myeloma. Finally, we describe the unique adaptations of the microenvironment as a response to distinct genomic changes in myeloma cells. These results further our knowledge to characterize myeloma precursor disease evolution, inform individual patient progression risk stratification and identify potential biomarkers that could be clinically exploited.

  Study EGAS00001006694

• The genomic landscape of follicular and diffuse large B-cell lymphoma

  As part of the ICGC, the ICGC MMML-Seq project performed whole genome sequencing and RNA sequencing of follicular and diffuse large B-cell lymphoma. Follicular and diffuse large B-cell lymphomas are the most common B-cell lymphomas in adulthood. Analyses were performed in concordance with the guidelines of the ICGC. The results define the genomic landscape of structural variants, somatic single nucleotide variants and mutational signatures in these lymphomas

  Study EGAS00001002199

• Single-cell and bulk RNA-sequencing of nivolumab-treated glioblastoma

  Glioblastoma is a highly aggressive type of brain tumour for which there is no curative treatment available. Immunotherapies have shown limited responses in unselected glioblastoma patients, and it is currently not well understood what separates the few responders from the non-responders at the cellular and molecular level. Here we investigate the phenotypic and transcriptional evolutionary dynamics at single-cell resolution during nivolumab immune checkpoint treatment of eight glioblastoma patients enrolled in a translational phase I/II clinical trial.

  Study EGAS00001007110

• RNA-seq of Glioblastoma stem cells

  Chromatin accessibility discriminates stem from mature cell populations, enabling the identification of primitive stem-like cells in primary tumors, such as Glioblastoma (GBM) where self-renewing cells driving cancer progression and recurrence are prime targets for therapeutic intervention. We show, using single-cell chromatin accessibility, that primary GBMs harbor a heterogeneous self-renewing population whose diversity is captured in patient-derived glioblastoma stem cells (GSCs). In depth characterization of chromatin accessibility in GSCs identifies three GSC states: Reactive, Constructive, and Invasive, each governed by uniquely essential transcription factors and present within GBMs in varying proportions. Orthotopic xenografts reveal that GSC states associate with survival, and identify an invasive GSC signature predictive of low patient survival. Our chromatin-driven characterization of GSC states improves prognostic precision and identifies dependencies to guide combination therapies.

  Study EGAS00001003070

• Molecular profiling of metastatic uveal melanoma

  Metastatic uveal melanoma is less well understood than its primary counterpart, has a distinct biology compared to skin melanoma and lacks effective treatments. Here we genomically profile metastatic tumors and infiltrating lymphocytes. BAP1 alterations were overrepresented and occurred in 29/32 of cases. An outlier tumor had high mutational burden associated with UV-damage. CDKN2A deletions also occurred, which are rarely present in primaries. We profiled recurrent copy number alterations associated with metastasis and performed a focused knockdown screen on overexpressed targets. We investigated the role of BAP1 by reintroducing a functional allele into a deficient patient-derived cell line, revealing a broad shift towards a transcriptomic subtype associated with better prognosis. Tumor-infiltrating lymphocytes were in several cases tumor-reactive, but expression of the immune checkpoint receptors TIM-3, TIGIT and LAG3 was abundant. This study represents the largest whole-genome analysis of uveal melanoma to date and presents an updated view of the metastatic disease.

  Study EGAS00001004296

• Molecular subsets in renal cancer determine outcome to checkpoint and angiogenesis blockade

  We conducted integrated multi-omics evaluation of 823 tumors from advanced renal cell carcinoma (RCC) patients and identified molecular subsets associated with differential clinical outcomes to angiogenesis blockade alone or with a checkpoint inhibitor. Unsupervised transcriptomic analysis revealed six molecular subsets with distinct angiogenesis, immune, cell cycle, metabolism, and stromal programs. While sunitinib was effective in subsets with high angiogenesis, atezolizumab+bevacizumab improved clinical benefit in tumors with high T-effector and/or cell cycle transcription. Somatic mutations in PBRM1 and KDM5C associated with high angiogenesis and AMPK/Fatty acid oxidation gene expression, while CDKN2A/B and TP53 alterations were more prevalent in tumors with increased cell cycle and anabolic metabolism. Sarcomatoid tumors exhibited low prevalence of PBRM1 mutations and angiogenesis markers, frequent CDKN2A/B, BAP1 and TP53 alterations, and increased PD-L1 expression. These findings can be applied to molecularly stratify advanced RCC patients, explain improved outcomes of sarcomatoid tumors to checkpoint blockade, and develop personalized therapies.

  Study EGAS00001004353

• glioblastoma and glioblastoma stem cells (GSCs), RNA-seq and WGS

  Characterization of glioblastoma tumors and glioblastoma stem cells (GSCs) lines via RNA-seq and/or WGS profiling.

  Study EGAS00001004395