8215 results for "canc*"

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• Distinct genomic profiles and clinical outcomes in constitutional mismatch repair deficiency-associated high-grade gliomas: insights into mutational signatures and clonal evolution

  Constitutional mismatch repair deficiency (CMMRD) is a rare cancer-predisposition syndrome, yet the mutational processes and clonal evolution of CMMRD-associated high-grade gliomas (HGGs) remain incompletely understood. In this study, mutational signatures and tumor evolution were analyzed in 25 CMMRD-associated HGGs. Germline biallelic mutations were most frequently identified in MSH6 (56.0%), followed by PMS2 (36.0%) and MLH1 (8.0%). Affected patients showed very early disease onset (mean 5.8 years) and poor clinical outcomes, with a mean progression-free survival of 16 months. Distinct genomic and clinical differences were observed between MSH6- and PMS2-associated tumors. MSH6-deficient HGGs were enriched for SBS6, whereas PMS2-deficient tumors showed predominance of SBS21, and these mutational signatures were correlated with prognosis. Clonal evolution analyses revealed early involvement of POLE/POLD1 mutations and persistence of the founding clone at recurrence. Overall, the study highlights the importance of mutational signatures and clonal evolution in shaping tumor behavior and clinical outcomes in CMMRD-associated HGGs.

  Study EGAS50000001506

• Molecular investigation of BCC HHI-ICI combination therapy

  We collected skin biopsies and PBMCs of patients with advanced BCC who underwent HHI-ICI combination therapy. We analyzed the skin biopsies with STx and the PBMCs with scRNA-seq to characterize the response of the immune cells, tumor cells and the tumor microenvironment to this therapy. We were interested in immune activation upon HHI and how that synergises with subsequent ICI.

  Study EGAS50000001481

• Targeted next-generation sequencing of 13 chordoid gliomas of the third ventricle

  Study EGAS00001002733

• The Dynamic Immune Behavior of Primary and Metastatic Ovarian Carcinoma

  Patients with high-grade serous ovarian carcinoma are usually diagnosed at an advanced stage and often develop resistance to conventional therapy. Epithelial ovarian tumors have been shown to be rich in CD8+ lymphocytes, which infiltrate both primary and omental sites. In recent years, several prominent studies have highlighted a positive association between the presence of these immune cells and a good prognosis; however, clinical trials of immune checkpoint inhibitors have so far shown unsatisfactory results in ovarian cancer. In this study, we used an innovative combination of single-cell sequencing and spatial transcriptomics to identify the molecular mechanisms that lead to immunosuppression in primary and metastatic HGSC. Primary tumors consistently showed a more active immune microenvironment than did omental tumors. In addition, while several immune cell subtypes were present in all samples, their relative abundance differed between primary and omental tumors. Finally, we found that primary tumors were mostly populated by dysfunctional CD4 and CD8 T cells in later stages of differentiation, while omental tumors were mostly populated by naïve immune cells; this, in turn, was correlated with expression changes in the interferon α and γ pathways in epithelial cells, showing that cross-communication between the epithelial and immune compartments is important for immune suppression in ovarian cancer. These findings can impact the timing and choice of immune-modulating drugs and should be considered when planning treatment for patients with high-grade serous ovarian carcinoma.

  Study EGAS50000000038

• Molecular Classification of Lymph Node Metastases Subtypes Predict for Survival in Head and Neck Cancer

  Study EGAS00001003233

• Phenotypic characterization and prognostic impact of CD103+ tissue-resident memory T cells in diffuse large B cell lymphoma

  Tissue-resident memory T (TRM) cells are a population of memory T cells that stably occupy tissues and play a key role in immunosurveillance, having been linked to favorable survival outcomes in various solid tumors. While TRM cells have been identified in lymph nodes, their phenotype and prognostic significance in B-cell non-Hodgkin lymphoma (B-NHL), including diffuse large B-cell lymphoma (DLBCL), remains poorly characterized. The frequency of CD103 expressing T cells in patient samples with DLCBL was quantified by immunofluorescence (IF) staining of tissue biopsies (n=306) and flow cytometry (n=252) of cell disaggregates, and linked with clinical outcome. The phenotype of TRM cells was characterized by spectral flow cytometry (n=10 DLBCL and 2 reactive lymph node (rLN) samples) and single-cell RNA sequencing (scRNAseq) (n=12 aggressive B cell lymphomas and 4 rLN samples). An additional 51 samples from an external dataset were included to verify the single cell transcriptome findings. The flow cytometry and scRNAseq findings in DLBCL were extrapolated to additional B-NHL entities. Through analysis of these datasets we were able to characterize CD103+ TRM-like cells in DLBCL and other B-NHL entities and identified them to represent a prognostically favorable population with an activated/cytotoxic T cell phenotype.

  Study EGAS50000000943

• Linked-Read Whole Genome Sequencing Profiles Structural Variant Landscape of Gliomas with Barcode-Level Evidence

  Structural variants (SVs) play essential roles in glioma oncogenesis and offer prognostic insights, yet the SV landscape of gliomas has not been completely characterized due to previous technological limitations. To comprehensively profile the SV landscape of gliomas, we performed linked-read whole genome sequencing (LR-WGS) on 31 tumour samples from 20 glioma patients. Using barcode-level evidence, we validated known SVs and identified the presence of extrachromosomal DNA containing the EGFR sequence, which correlates with elevated EGFR expression. Additionally, we uncovered rare SVs affecting genes typically mutated by single nucleotide variants (SNVs), including those in the SWI/SNF chromatin remodeling complex. Our analysis also reveals selective chromosomal vulnerabilities to SVs, highlighting certain chromosomes as hotspots for SV accumulation. Collectively, our results demonstrate the utility of LR-WGS in accurately detecting SVs and thoroughly profiling SV landscapes using barcode-level evidence. The insights gained into the synergistic effects of SNVs and SVs on oncogenes further underscore the importance of integrating SV analysis when examining mutations in gliomas.

  Study EGAS50000000947

• Genome-wide analyses of cell-free DNA for therapeutic monitoring of patients with pancreatic cancer

  Determining response to therapy for patients with pancreatic cancer can be challenging. We evaluated methods for assessing therapeutic response using cell-free DNA (cfDNA) in plasma samples from 40 patients with metastatic pancreatic cancer as part of the CheckPAC trial (NCT02866383). Patients were evaluated before and after initiation of therapy using tumor-informed plasma whole-genome sequencing (WGMAF), and genome-wide cfDNA fragmentation profiles and repeat landscapes (ARTEMIS-DELFI). Of those assessed with WGMAF, molecular responders had a median overall survival (OS) of 319 days compared to 126 days for non-responders (HR=0.29, 95% CI=0.11–0.79, p=0.011). For ARTEMIS-DELFI, patients with low scores after therapy initiation had a longer median OS than patients with high scores (233 days versus 172 days, HR=0.12, 95% CI=0.046-0.31, p<0.0001). We validated ARTEMIS-DELFI in a separate cohort of 40 patients with pancreatic cancer who were part of the PACTO trial (NCT02767557). These analyses suggest that non-invasive mutation and fragmentation-based cfDNA approaches can identify therapeutic response of individuals with pancreatic cancer.

  Study EGAS50000000923

• Genetic alterations in metastatic uveal melanoma

  Study EGAS00001003303

• Enhancer profiling identifies epigenetic markers of endocrine resistance and reveals therapeutic options for metastatic castration-resistant prostate cancer patients (LuCaP cell line data)

  Androgen Receptor (AR) signaling inhibitors, including enzalutamide, are treatment options for patients with metastatic castration-resistant prostate cancer (mCRPC), but resistance inevitably develops. Using metastatic samples from a prospective phase II clinical trial, we epigenetically profiled enhancer/promoter activities with H3K27ac chromatin immunoprecipitation followed by sequencing, before and after AR-targeted therapy. We identified a distinct subset of H3K27ac-differentially marked regions that associated with treatment responsiveness. These data were successfully validated in mCRPC patient-derived xenograft models (PDX). In silico analyses revealed HDAC3 as a critical factor that can drive resistance to hormonal interventions, which we validated in vitro. Critically, we identified the pan-HDAC inhibitor, vorinostat to be effective in decreasing tumor cell proliferation both in vitro and in vivo. Moreover, we uncovered evidence for HDAC3 working together with Glucocorticoid Receptor (GR) as a potential mechanism for this therapeutic effect. These findings demonstrate rationale for new therapeutic strategies including HDAC inhibitors to improve patient outcome in advanced stages of mCRPC. Project Goal: We identified H3K27ac regions associated with resistance in patient samples. Extensive analysis of these regions suggested that HDAC3 may play a role in resistance. To test this, we analyzed ChIP-seq and RNA-seq from cell lines generated from PDX LuCaP samples (recapitulating resistant and non-resistant) to validate findings in patient samples. ChIP-seq samples were used to verify the signals identified from specific factors, such as H3K27ac, AR, FOXA1, GR and HDAC3, their association with resistance and possible mechanisms of action. RNA-seq samples were analyzed to determine the effect of AR signaling in these samples in specific genes in the H3K27ac resistance-associated regions.

  Study EGAS50000000917