22938 results for "ega"

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  Dac EGAC00001000487

• Pharmacological improvement of CFTR function rescues airway epithelial homeostasis and host defense in cystic fibrosis children

  Rationale: Recent clinical trials have shown that elexacaftor/tezacaftor/ivacaftor (ETI) provides significant benefit to patients with cystic fibrosis (CF) by improving CFTR function. Despite these promising clinical findings, the specific effects on the airway inflammatory status leading to structural damage and impaired lung function, remain elusive. Objectives: We investigated the transcriptional changes at the single cell level of airway epithelial and immune cells that underlie the clinical improvement by ETI therapy in children with CF. Methods: Nasal swabs from thirteen children with CF and at least one F508del allele aged 6 to 12 years were collected at baseline and three months after initiation of ETI and subjected to scRNA-seq. In addition, we collected nasal swabs from 12 age- and sex-matched controls. Sweat chloride concentrations, spirometry and multiple breath washout were used for clinical evaluation of CF children. Measurements and main results: ETI significantly reduced sweat chloride concentrations (-52.2 ± 14.3 mmol/L, P < 0.001) and improved the lung clearance index (-1.3 ± 1.8, P < 0.05). Single cell transcriptomics revealed an impaired interferon signalling in epithelial cells of CF children at baseline, which was partially restored by ETI in conjunction with an ETI-induced increase in expression of MHC I and II encoding genes similar to control levels. Additionally, ETI markedly reduced the inflammatory phenotype of immune cells, particularly of neutrophils and macrophages. Conclusions: Improvement of CFTR function by ETI restores epithelial homeostasis and reduces immune cell inflammatory responses in the upper airways of children with CF, highlighting the potential of early initiation of ETI therapy.

  Study EGAS50000000128

• Systemic Lupus Erythematosus Serum Stimulation of Human Intestinal Organoids Induces Barrier Leakiness and Changes in Goblet Cell Differentiation

  Human intestinal epithelial cells are the interface between potentially harmful luminal content and basally residing immune cells. Their role is not only nutrient absorption but also the formation of a tight monolayer that constantly secretes mucus creating a multi-layered protective barrier. Alterations in this barrier can lead to increased gut permeability which is frequently seen in individuals with chronic extraintestinal autoimmune diseases, such as Systemic Lupus Erythematosus (SLE). Despite recent advances in identifying alterations in gut microbiota composition in SLE patients, not much attention has been given to the epithelial barrier itself. To date, it remains largely unexplored which role and function intestinal epithelial cells have in SLE pathology. Here, we present a unique near-physiologic in vitro model specifically designed to examine the effects of SLE on the epithelial cells. We utilize human colon organoids that are stimulated with serum obtained from SLE patients. Combining bulk and single-cell RNA transcriptomic analysis with functional assays revealed that SLE serum stimulation induced a unique expression profile marked by a reduction of goblet cell marker expression and mucus composition. Additionally, organoids exhibited imbalanced cellulat composition along with enhanced paracellular permeability,mitochondrial function, and a type I interferon gene signature. Similarly, transcriptomic analysis of SLE human colon biopsies revealed a downregulation of epithelial secretory markers. Our work uncovers a crucial connection between SLE and intestinal homeostasis that might be promoted in vivo through the blood, offering insights into the causal connection of barrier dysfunction and autoimmune diseases.

  Study EGAS50000000012

• Carboxylesterase 1 mediates a distinctive metabolic profile of dendritic cells to attain an inflammatory phenotype

  The metabolic profile of dendritic cells (DCs) shapes their phenotype and functions. Carboxylestrase 1 (CES1) enzyme is highly expressed in mononuclear myeloid cells however its exact role in DCs is elusive. We used a CES1 inhibitor (WWL113) and genetic overexpression to explore the role of CES1 in DCs differentiation in inflammatory models. CES1 expression was analyzed during CD14+ monocytes differentiation to DCs (MoDCs) using quantitative PCR. CES1 Inhibitor (WWL113) was applied during MoDCs differentiation. Surface markers, secreted cytokines, lactic acid production, phagocytic and T cell polarization capacity were analyzed. Transcriptomic and metabolic profile were assessed with RNA-sequencing and mass spectrometry. Cellular respiration was assessed with seahorse respirometry. Transgenic mice were used to assess CES1 overexpression in DCs in inflammatory models. CES1 expression peaks early during MoDCs differentiation. Pharmacological inhibition of CES1 led to higher expression of CD209, CD86 and MHCII. WWL113 treated MoDCs secreted higher quantities of IL6, IL8, TNF and IL10 and demonstrated stronger phagocytic ability and higher capacity to polarize Th17 differentiation in autologous DCs-T cells co-culture model. Transcriptomic profiling revealed enrichment of multiple inflammatory and metabolic pathways. Functional metabolic analysis shows impaired maximal mitochondrial respiration capacity, increased lactate production and decreased intracellular amino acids and TCA intermediates. Transgenic human CES1 overexpression in murine DCs generated less inflammatory phenotype and increased resistance to T cell mediated colitis. In conclusion, CES1 inhibition directs DCs differentiation towards more inflammatory phenotype, that shows stronger phagocytic capacity and supports Th17 skewing. This is associated with disrupted mitochondrial respiration and amino acids depletion.

  Study EGAS50000000230

• Cerebrospinal fluid cfDNA sequencing for classification of central nervous system glioma

  Primary central nervous system (CNS) gliomas can be classified by characteristic genetic alterations. In addition to solid tissue obtained by surgery or biopsy, cell-free DNA (cfDNA) derived from cerebrospinal fluid (CSF) is an alternative source of material for genomic analyses. Experimental design: We performed targeted next-generation sequencing (NGS) of CSF cfDNA in a representative cohort of 85 patients presenting with with suspicion of primary or recurrent glioma at two neurooncological centers. Copy-number variation (CNV) profiles, single nucleotide variants (SNVs), and small insertions/ deletions (indels) were combined into a molecular-guided tumor classification. Comparison with the solid tumor was performed for 38 cases with matching solid tissue available. Results: Cases were stratified into four groups: glioblastoma (n = 32), other glioma (n = 19), non-malignant (n = 17) and no confirmed diagnosis available (n = 17). We introduce a molecular-guided tumor classification, enabling identification of tumor entities and/ or cancer specific alterations in 75.0 % (n = 24) of glioblastoma and 52.6 % (n = 10) of other glioma cases. The overlap between CSF and matching solid tissue was highest for CNVs (26-48 %) and SNVs at pre-defined gene loci (44 %), followed by SNVs/indels identified via uninformed variant calling (8-14 %). A molecular-guided tumor classification was made 23.5 % (n = 4) of cases with no confirmed diagnosis available. Conclusions: We developed a workflow for targeted sequencing of CSF cfDNA as well as a strategy for interpretation and reporting of sequencing results based on a molecular-guided tumor classification in glioma.

  Study EGAS50000000060

• Circulating tumor DNA dynamics reveal KRAS G12C mutation heterogeneity and response to treatment with the KRAS G12C inhibitor divarasib in solid tumors

  Purpose: To inform prognosis, treatment response, disease biology, and KRAS G12C mutation heterogeneity, we conducted exploratory circulating tumor DNA (ctDNA) profiling on 134 patients with solid tumors harboring a KRAS G12C mutation treated with single-agent divarasib (GDC-6036) in a phase 1 study. Experimental design: Plasma samples were collected for serial ctDNA profiling at baseline (Cycle 1 Day 1 prior to treatment) and multiple on-treatment time points (Cycle 1 Day 15 and Cycle 3 Day 1). Results: KRAS G12C ctDNA was detectable from plasma samples in 72.9% (43/59) and 92.6% (50/54) of patients with non-small cell lung cancer and colorectal cancer, respectively, the majority of whom were eligible for study participation based on a local test detecting the KRAS G12C mutation in tumor tissue. Baseline ctDNA tumor fraction was associated with tumor type, disease burden, and metastatic sites. A decline in ctDNA level was observed as early as Cycle 1 Day 15. Serial assessment showed a decline in ctDNA tumor fraction associated with response and progression-free survival. Except for a few cases of KRAS G12C sub-clonality, on-treatment changes in KRAS G12C variant allele frequency mirrored changes in the overall ctDNA tumor fraction. Conclusion: Across tumor types, the KRAS G12C mutation likely represents a truncal mutation in the majority of patients. Rapid and deep decline in ctDNA tumor fraction was observed in patients responding to divarasib treatment. Early on-treatment dynamics of ctDNA were associated with patient outcomes and tumor response to divarasib treatment.

  Study EGAS50000000315

• Lactate metabolism in cancer stem cell fate regulation

  Tumors arise as a result of uncontrolled cell proliferation driven by mutations in the signaling pathways that regulate the balance between cell division and differentiation. Despite of that, in the tumor, cancer stem cells seem to retain their capability to differentiate, which can lead to differential chemotherapy response. We previously showed that intestinal stem cells and differentiated cells display specific metabolic features and that they interact through metabolites. Moreover, we found that altering mitochondrial metabolism is sufficient to lead and define stem cell differentiation. In cancer, cellular metabolism is highly derailed. However, how metabolic changes in the cancer cell contribute to cell fate decisions remains unknown. Recently, the crosstalk between metabolism and epigenetics has emerged as one of the players in tumor development. Here we aim to address the impact of the altered metabolism of cancer cells on their epigenome as a regulatory axis of cell identity and fate. We use human-derived tumor organoids where we introduce genetic encoded fluorescent-based reporters to visualize cell identity and metabolism at single cell level. We combine 4D live imaging with a recently developed machine learning method to re-construct cell-lineages, trace stem cell state and metabolic changes during tumor organoid development. We find that, mimicking the tumor metabolic microenvironment (Warburg effect-driven low-glucose high-lactate) leads to changes cellular metabolism and histone acetylation. Strikingly, these alterations provoke profound changes in tumor development by increasing the population of cancer stem cells and their proliferation and differentiation dynamics.

  Study EGAS50000000063

• Tumor Evolution Analysis Uncovered Immune-Escape Related Mutations in Relapsed Diffuse Large B-Cell Lymphoma

  More than 60% of patients with primary diffuse large B-cell lymphoma (DLBCL) achieve durable remissions upon the chemoimmunotherapy with R-CHOP. However, the outcome of the relapse patients is extremely poor. To characterize the molecular features that underlie treatment resistance, we performed whole-exome sequencing (n=44) and deep targeted sequencing (n=27) of 44 diagnosis-relapse DLBCL pairs. We found that the overall landscape of genetic alterations was concordant between diagnosis and relapse DLBCL. By a deep comparison of the longitudinal sequencings, we identified relapse-enriched mutations that involved in evasion of immune surveillance (CD58, TNFRSF14, PKD1, FAS), resistance to DNA damaging agents (ATM, TP53), and critical tumor suppressor gene (ZFHX3). Knockdown of ATM and ZFHX3 resulted in increased drug resistance in both germinal center B cell like (GCB) and activated B cell like (ABC) DLBCL cell lines in vitro, while the knockdown of TNFRSF14 and FAS conferred resistance specifically in GCB cell lines. Furthermore, we summarized two evolutionary patterns of DLBCL relapse as the “durable retention” model with stable clone structure, and the “selective sweep” model which exhibited significant clonal switch. Of note, genetic alterations leading to attenuated immune responses usually presented as trunk mutations in the “durable retention” model (7/12) while were newly acquired or expanded upon relapse in the “selective sweep” model (9/16). Overall, our study demonstrated that relapse DLBCL derives from distinct clonal evolutionary patterns, and highlighted immune escape as an important contributor of tumor relapse.

  Study EGAS50000000032

• Surgery in combination with immune checkpoint therapy as an effective treatment for patients with metastatic cancer.

  Abstract Surgical removal of primary tumors was shown to reverse tumor-mediated immune suppression in pre-clinical models with metastatic disease. However, how cytoreductive surgery in the metastatic setting modulates the immune responses in patients, especially in the context of immune checkpoint therapy (ICT)-containing treatments is not understood. Here, we report the first prospective, non-comparative clinical trial (N=104) using three different ICT-containing strategies plus cytoreductive or “debulking” surgery to remove the primary tumor-bearing kidney or a metastatic lesion as a treatment for patients (N=43) with metastatic clear cell renal cell carcinoma (mccRCC). For those patients (N=61) who were not candidates for cytoreductive surgery, a biopsy was obtained instead for correlative biological studies. Our data demonstrated that the combination of ICT with cytoreductive surgery was safe and feasible in patients with mccRCC. The 2-year overall survival was 84% with a median OS of 54.7 months for patients who received ICT containing regimens plus surgery. Immune-monitoring studies with co-detection by indexing (CODEX) identified distinct tumor spatial conformation of cellular subsets as a novel and improved predictor of response to ICT. Importantly, single-cell RNA-sequencing data demonstrated that surgical removal of the tumor increased antigen-presenting dendritic cell population with a concurrent reduction in KDM6B expressing immune-suppressive myeloid cells in the peripheral blood. Together, this study highlighted the feasibility of combining ICT with cytoreductive surgery in a metastatic setting and demonstrated potential enhancement of immune responses following ICT plus cytoreductive surgery in patients with metastatic disease.

  Study EGAS00001005667

• Impact of Glycolysis Inhibition on the Epigenome of Synovial Fluid T Cells in Juvenile Idiopathic Arthritis

  Juvenile Idiopathic Arthritis (JIA) encompasses a group of childhood-onset autoimmune conditions characterized by joint inflammation and mononuclear cell infiltration, especially of activated CD4+ memory/effector T (Tmem/Teff) cells in synovial fluid (SF). JIA CD4+ T cells exhibit a distinct inflammation-associated epigenomic profile, though the underlying molecular mechanisms remain unclear. This study investigates the role of glycolysis in shaping the epigenomic landscape of JIA SF CD4+ T cells, with a focus on H3K27ac histone modifications. Using an ex vivo model of antigen stimulation, CD4+ T cells were isolated from peripheral blood (PB) of healthy controls (HC) and synovial fluid from JIA patients. Cells were activated in vitro with anti-CD3/CD28 for 24 hours, and changes in H3K27ac were assessed by chromatin immunoprecipitation followed by sequencing (ChIP-seq). To explore the specific role of glycolysis, cells were also treated with 2-deoxyglucose (2DG), an inhibitor of glucose-6-phosphate production. This inhibition impacted both H3K27ac acetylation patterns and gene expression associated with the activated epigenomic regions. Additionally, HC CD4+ T cells were activated in vitro in the presence of 30% SF or 30% plasma from JIA patients. RNA sequencing (RNA-seq) was performed to examine SF-induced transcriptional changes, providing insight into the metabolic dysregulation and epigenomic alterations observed in JIA SF CD4+ T cells. This dataset includes ChIP-seq and RNA-seq data that collectively advance our understanding of how glycolysis and the SF environment contribute to the epigenetic and transcriptional regulation in JIA CD4+ T cells.

  Study EGAS50000000808