4957 results for "*oma"

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• Targets of MEK inhibition in DIPG

  The survival of children with diffuse intrinsic pontine glioma (DIPG) remains dismal, with new treatments desperately needed. In the era of precision medicine, targeted therapies represent an exciting treatment opportunity, yet resistance can rapidly emerge, playing an important role in treatment failure. In a prospective biopsy-stratified clinical trial, we combined detailed molecular profiling (methylation BeadArray, exome, RNAseq, phospho-proteomics) linked to drug screening in newly-established patient-derived models of DIPG in vitro and in vivo. We identified a high degree of in vitro sensitivity to the MEK inhibitor trametinib in samples which harboured genetic alterations targeting the MAPK pathway, including the non-canonical BRAF_G469V mutation, and those affecting PIK3R1 and NF1. However, treatment of PDX models and of a patient with trametinib at relapse failed to elicit a significant response. We generated trametinib-resistant clones in the BRAF_G469V model through continuous drug exposure, and identified acquired mutations in MEK1/2 (MEK1_K57N, MEK1_I141S and MEK2_I115N) with sustained pathway up-regulation. These cells showed the hallmarks of mesenchymal transition, and expression signatures overlapping with inherently trametinib-insensitive primary patient-derived cells that predicted an observed sensitivity to dasatinib. Combinations of trametinib with dasatinib and the downstream ERK inhibitor ulixertinib showed highly synergistic effects in vitro. These data highlight the MAPK pathway as a therapeutic target in DIPG, and show the importance of parallel resistance modelling and rational combinatorial treatments likely to be required for meaningful clinical translation.

  Study EGAS00001004495

• A Multifactorial Tumor and Immune Cell Profile Determines Response to Immune Checkpoint blockade in Melanoma

  The complex crosstalk between tumor and immune cells during immune checkpoint blockade mandates the development of integrated models that interpret the anti-tumor immune response and predict clinical outcome. We have integrated genome-wide sequence and structural alterations with pre and on-therapy transcriptomic and T cell repertoire features for a cohort of 64 immunotherapy-naïve melanomas treated with anti-PD1 monotherapy or combined anti-PD1 and anti-CTLA4 therapy. While tumor mutation burden (TMB) was associated with improved response to therapy, expressed mutation burden was superior to TMB in predicting outcome. An increased pre-existing T cell density differentiated responding from non-responding tumors independent of therapy. Importantly, T cell repertoire reshaping determined by T cell receptor (TCR) clonotypic regressions and expansions reflected response to therapy such that a more dynamic repertoire predicted improved clinical outcome. Through whole-transcriptome analyses, we discovered differential abundance of B cell subsets in responding tumors, which highlights the importance of the interplay between pre-existing T and B cell immunity in shaping therapeutic response. Tumor temporal trajectories during therapy revealed distinct patterns of molecular response related to expressed mutation elimination or retention that accurately interpreted clinical response. High-dimensional genomic, transcriptomic and immune repertoire data were integrated by both a machine learning and a censored regression approach, resulting in a harmonized multi-modal predictor of response to immune checkpoint blockade. B cell abundance, expressed mutation load and tumor aneuploidy were combined to identify patients at high risk for recurrence, such that high risk patients had a significantly shorter progression-free survival (HR=9.18, 95% CI: 3.14-26.85, p=3.4e-06) especially in the anti-PD1/anti-CTLA4 group (HR=20.34, 95% CI: 4.08-101.32, p=1.68e-06).

  Study EGAS00001004548

• Bone marrow breakout lesions act as key sites for tumor-immune cell diversification and exhaustion in multiple myeloma

  Multiple myeloma is a disease characterized by the expansion of cancerous plasma cells in the bone marrow. The bone marrow microenvironment plays a pivotal role in supporting myeloma growth and modulating tumor immunity. As the disease progresses, myeloma cells may become independent of the bone marrow environment, leading to extramedullary disease associated with poor prognosis. However, the early processes associated with bone marrow independence and its implications for disease and immune control remain poorly understood. Here, we employed comprehensive single-cell and spatial mapping to identify the disruption of the cortical bone and subsequent expansion of myeloma cells in breakout lesions as a key event in multiple myeloma pathogenesis and tumor immunity. Breakout lesions harbor an adapted niche and a unique immune microenvironment conferred by sustained immune-tumor interactions. In particular, tumor-reactive T cells with a highly exhausted phenotype, alongside unique NK cell and macrophage subtypes, specifically expanded in breakout lesions. Spatially-resolved genomic, transcriptomic and cellular analyses uncovered extensive intra-lesion heterogeneity, suggesting a divergent co-evolution of genomic variation and locally confined T cell responses in distinct subregions. Ultra-high plex imaging revealed that tumor-reactive T cells, together with other immune-regulatory cells and dendritic cells, co-expand and exhaust upon sustained tumor interactions in locally confined immune islands. In contrast, immune-regulatory macrophage and NK cell subsets operate spatially separated within myeloma cell deserts. Jointly, our analyses uncover bone marrow breakout lesions as a hotspot for tumor-immune cell interactions, diversification and exhaustion, representing a key event in myeloma pathogenesis with significant therapeutic implications.

  Study EGAS50000000304

• Genetic and Microenvironmental Analysis of Peripheral T-cell Lymphoma

  This study enrolled 129 patients diagnosed with PTCL, comprising 94 cases of nTFHL and 35 cases of PTCL-NOS. Whole exome sequencing (WES) and RNA sequencing (RNA-seq) were performed using DNA and RNA of sufficient quality extracted from their tumor specimens. WES was conducted for all 129 cases, while RNA-seq was performed on 57 tumor samples.

  Study EGAS50000001258

• Identification of putative multiple myeloma (MM) susceptibility genes

  We sought to identify novel MM susceptibility genes using a collection of families with multiple cases of MM/MGUS, including 189 affected individuals from 40 families, and index cases from an additional 88 families, along with 170 early-onset (EO) MM cases (≤ 55 years). We analyzed a total of 347 affected individuals using whole exome (N=321) and whole genome (N=26) sequencing. Samples were identified and collected through nation-wide efforts in France, Sweden and Greece. We focused on rare (MAF<0.5%) germline protein truncating and likely deleterious missense variants in genes harboring variants in at least two families showing variant-disease segregation, and in additional index (≥2) and/or early-onset (≥2) cases.

  Study EGAS50000001259

• Mutational Landscape and Tumor Burden Assessed by Cell-Free DNA in Diffuse Large B-Cell Lymphoma: a Population-based Study

  Purpose: We analyzed the utility of cfDNA in a prospective population-based cohort to determine the mutational profile, assess tumor burden, and estimate its impact in response rate and outcome in patients with DLBCL. Experimental Design: One-hundred patients were diagnosed with DLBCL during the study period. Mutational status of 112 genes was studied in cfDNA by targeted next-generation sequencing. Paired formalin-fixed paraffin-embedded samples and volumetric PET/CT were assessed when available. Results: Appropriate cfDNA to perform the analyses was obtained in 79/100 cases. At least one mutation could be detected in 69/79 cases (87%). The sensitivity of cfDNA to detect the mutations was 68% (95% CI: 56.2-78.7). The mutational landscape found in cfDNA samples was highly consistent with that shown in the tissue and allowed genetic classification in 43% of the cases. A higher amount of ctDNA significantly correlated with clinical parameters related to tumor burden (elevated LDH and β2-microglobulin serum levels, advanced stage, and high-risk IPI) and total metabolic tumor volume assessed by PET/CT. In patients treated with curative intent, high ctDNA levels (&amp;gt;2.5 log hGE/mL) were associated with lower complete response (65% vs. 96%, P&amp;lt;0.004), shorter progression-free survival (65% vs. 85%, P=0.038) and overall survival (73% vs. 100%, P=0.007) at 2 years, although it did not maintain prognostic value in multivariate analyses. Conclusions: In a population-based prospective DLBCL series, cfDNA resulted an alternative source to estimate tumor burden and to determine the tumor mutational profile and genetic classification, which have prognostic implications and may contribute to a future tailored

  Study EGAS00001004733

• SDR-seq_06_BCL

  Multiomic targeted scDNA-scRNA-seq (SDR-seq) of primary B-cell non-Hodgkin lymphomas. Aim is to link genomci variants to gene expression in single cells. Profiled two follicular lymphoma (FL) primary patient samples and one germinal center subtype diffuse large B-cell lymphoma (GCB) primary patient sample.

  Study EGAS50000000374

• MEMORI WES bams

  This project stores bam files from deep whole exome sequencing from oesophageal adenocarcinoma at different timepoints during neoadjuvant treatment (prior, during, post treatment), which were used to analyse evolutionary and phenotype dynamics in oesophageal adenocarcinoma during neoadjuvant treatment.

  Study EGAS50000000240

• Whole exome sequencing of FFPE material from 41 pediatric BCP-LBL patients.

  This study contain the results of whole exome sequencing analyses of FFPE material from 41 pediatric B-cell precursor lymphoblastic lymphoma patients. Samples were sequenced with a target coverage of 200x. Data are provided as Fastq files.

  Study EGAS50000000290

• Whole exome RNA sequencing of FFPE material from 49 pediatric BCP-LBL patients.

  This study contain the results of whole exome-targeted transcriptome analyses of FFPE material from 49 pediatric B-cell precursor lymphoblastic lymphoma patients. Data are provided as Fastq files.

  Study EGAS50000000289