5524 results for "*oma"

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• Epstein-Barr Virus status drives morphological and molecular intra-tumour heterogeneity in gastric cancer: insights from a case report and literature review

  This case report describes a rare case of bi-phenotypic gastric cancer with two distinct, but clonally related, histological components. The first component, associated with Epstein-Barr virus (EBV) infection, exhibited the morphological features of gastric carcinoma with lymphoid stroma, suggesting that EBV, as an effective immunogenic factor, may trigger a prominent immune response within the tumour microenvironment. The second component, which was EBV-negative, displayed tubular/papillary morphology and features of increased biological aggressiveness, such as high-grade areas and lymphatic invasion. Immunohistochemical and molecular studies confirmed that, despite the differing morphologies and immunophenotypes, both components were clonally related, with especially the EBV-negative area showing more complex DNA aberrations, reminiscent of Chromosomally instable (CIN) lesions. This case describes clonally related EBV-positive and negative components within a single gastric cancer, contributing to a better understanding of EBV role in tumour heterogeneity and progression and highlighting the impact of EBV loss on tumour behaviour.

  Study EGAS50000000706

• MET amplification in gastric cancer

  Targeting MET in gastric and gastroesophageal junction adenocarcinoma (GC) with monoclonal antibodies or tyrosine kinase inhibitors has had limited success. We hypothesize that other prognostic and response determining genetic alterations explain the poor outcome and lack of response to MET-targeted therapies.

  Study EGAS50000000744

• The genetic footprint of the European Roma diaspora: Evidence from the Balkans to the Iberian Peninsula

  Our genomic approach focuses on: (i) the internal genetic structure of Roma and its correlation with geography; (ii) the relationships between Iberian Roma and other non-Roma populations to explore possible contacts during the period of population upheaval following the Roma’s arrival on the Iberian Peninsula; (iii) estimation of the admixture events in the Iberian Roma before and after their arrival to the Iberian Peninsula; and (iv) the assessment of endogamy patterns and assortative mating of the European Roma. Our study provides a detailed analysis of the intricate population history of the Iberian Roma, offering insights from both micro-geographical and large-scale perspectives on the population history of European Roma.

  Study EGAS50000000746

• Nivolumab plus chemotherapy or ipilimumab in gastroesophageal cancer: CheckMate 649 biomarker analyses

  First-line nivolumab-plus-chemotherapy demonstrated superior overall survival (OS) versus chemotherapy for advanced gastroesophageal adenocarcinoma (CheckMate 649). Nivolumab-plus-ipilimumab provided durable responses and higher survival rates versus chemotherapy; however, the prespecified OS significance boundary was not met. To identify biomarkers predictive of differential efficacy outcomes, exploratory analyses were performed using whole-exome sequencing and RNA sequencing. Nivolumab-based therapies demonstrated improved efficacy versus chemotherapy in hypermutated and, to a lesser degree, Epstein Bar Virus-positive tumors compared with chromosomally unstable and genomically stable tumors. Within the KRAS-altered subgroup, only patients treated with nivolumab-plus-chemotherapy demonstrated improved OS benefit versus chemotherapy. Low stroma gene expression signature scores were associated with OS benefit with nivolumab-based regimens; high regulatory T-cell signatures were associated with OS benefit only with nivolumab-plus-ipilimumab. Our analyses suggest that distinct and overlapping pathways contribute to the efficacy of nivolumab-based regimens in gastroesophageal adenocarcinoma.

  Study EGAS50000000747

• Development of a fully human glioblastoma-in-brain-spheroid model for accelerated translational research

  In glioblastoma (GBM) the intricate interplay between tumor cells and the surrounding microenvironment plays a crucial role in tumor progression, invasion, and therapeutic resistance. So far, studying these interactions in a controlled and representative model system has been challenging. Here, we report the development of hGliCS, a human glioma-cortical spheroid model that allows the elucidation of the biology of GBM cells and their interactions with a human-specific brain-like microenvironment and neurons. GBM cells efficiently invade the cortical spheroids, forming a well-connected network of communicating cells. The heterogeneous cellular states of the GBM cells within this model closely resembled findings previously observed in glioblastoma patients and in mouse xenografts. We observed a transition from predominantly mesenchymal-like cells to heterotopic states with a high diversity. In contrast to the substantial changes observed in the tumor cell population, the impact of the GBM cells on the neurons was minimal. We further demonstrate the suitability of hGliCS to test compounds targeting tumor-specific neurobiological features.

  Study EGAS50000000757

• Analysis of T cells in follicular lymphoma

  This study aimed to identify new heterogeneities in human T cells of follicular lymphoma. To do so, we performed scRNA-seq of human lymph node and follicular lymphoma samples. We identified minor T cell subsets expanding in follicular lymphoma.

  Study EGAS50000000778

• Genomic Profiling of an anti-PD-L1 treated cohort of Newly Diagnosed GBM patients

  Checkpoint inhibitor therapy has limited efficacy in the outcomes of patients with glioblastoma (GBM). This study involves whole exome sequencing of newly diagnosed glioblastoma patients treated with concurrent atezolizumab, radiation therapy, and temozolomide. By analyzing 29 tumor-normal pairs, the study aims to explore the correlation between tumor genomics and the efficacy of PD-L1 blockade treatment outcomes and further identify which patients may benefit more from such therapy.

  Study EGAS50000000783

• Transcriptomic Profiling of an Anti-PD-L1 Treated Cohort of Newly Diagnosed GBM Patients

  Checkpoint inhibitor therapy has limited efficacy in glioblastoma patient outcomes. This study involves RNA sequencing (RNA-seq) of newly diagnosed GBM patients treated with concurrent atezolizumab, radiation therapy, and temozolomide. By analyzing RNA-seq data from 39 tumors, the study aims to explore tumor transcriptomic features, including immune-based transcriptomic programs and immune infiltration, to understand their influence on PD-L1 blockade treatment efficacy and to identify which patients may benefit more from such therapy.

  Study EGAS50000000784

• Single-cell Analysis of Neoplastic Plasma Cells Identifies Novel Myeloma Pathobiology Mediators and Potential Targets

  Newly diagnosed symptomatic and relapsed/refractory myeloma is a clonal plasma cell (PC) dyscrasia that arises from precursors which have been studied utilizing bulk or single-cell (sc) techniques. By combining scRNA-sequencing with scB-cell receptor (BCR)-sequencing, we found more dysregulated genes in monoclonal PCs compared with analyses of the entire CD138+ population, which includes non-neoplastic/polyclonal PCs. Paired tumor and non-tumor WGS was performed to evaluate the presence of IgH-associated translocations and hyperdiploidy events, initially detected by FISH, in a subset of samples included in this study.

  Study EGAS50000000801

• Genomic analysis of head and neck squamous cell carcinoma upon acquired resistance to cetuximab

  Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (cetuximab) remain the only FDA-approved targeted therapy for patients with recurrent/metastatic head and neck squamous cell carcinoma (HNSCC). Unfortunately, most patients develop acquired resistance to cetuximab and there is currently no further therapeutic option for these patients (unmet clinical need), thereby highlighting the need to better understand resistance-causing mechanisms. Here, we carried out whole-exome sequencing on 2 cetuximab-sensitive and -resistant patient-derived xenograft models of HNSCC. Our data reveal several genetic alterations (mutations and copy number variations) associated with acquired resistance to anti-EGFR therapy.

  Study EGAS50000000800