5522 results for "*oma"

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• Characterization of copy number quiet oral cancer

  Copy number quiet head and neck squamous cell carcinoma are a distinct subset with relatively good prognosis. Previous work has indicated this subset is most commonly found in the oral cavity and is highly enriched for HRAS and CASP8 mutations. TP53 mutations are much less common than in CNA-quiet oral cancers. In this study we corroborate the validity of CNA-quiet tumors as a distinct subset in a large OSCC cohort and further chart clinical, genomic, and immunological characteristics of this subset.

  Study EGAS50000000558

• 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

• Cancer cell and tumor microenvironment biomarkers associated with disease-free survival with adjuvant nivolumab in the phase 3 CheckMate 274 trial

  In the CheckMate 274 trial, adjuvant nivolumab versus placebo demonstrated an improvement in the primary endpoint of disease-free survival (DFS) in patients with high-risk muscle-invasive urothelial carcinoma after radical resection. An extensive analysis of tumor biomarkers, including their associations with DFS, was performed. Analysis of genome-wide differential gene expression and known gene signatures found that immune-related genes and pathways, in particular an IFNγ signature, were predictive of DFS in nivolumab-treated patients. Predictive and prognostic associations, respectively, were found for tumor-infiltrating CD4 and CD8 T cells. Analysis of a composite predictive model suggested that CD4 gene expression and tumor cell PD-L1 expression had the greatest contributions to predicting outcomes in nivolumab-treated patients. These results reinforce recent studies establishing the importance of biomarkers of adaptive immunity, and in particular CD4 T cells, in influencing response to PD-1/PD-L1 blockade and establish the potential predictive rather than solely prognostic nature of such findings.

  Study EGAS50000000560

• Transcriptome analysis of leiomyosarcoma

  We performed transcriptome analysis of leiomyosarcoma

  Study EGAS50000000594

• Targeted gene panel sequencing of leiomyosarcoma

  We conducted MSK-IMPACT sequencing of leiomyosarcoma.

  Study EGAS50000000595

• Tumor Profiler Melanoma Study

  The Tumor Profiler Study is an observational trial combining a prospective diagnostic approach to assess the relevance of in-depth tumor profiling to support clinical decision-making with an exploratory approach to improve the biological understanding of the disease. Technologies used are digital pathology, targeted NGS, single-cell RNA, single-cell DNA, bulk RNA, bulk proteotyping, single-cell CyTOF, imaging mass cytometry, pharmacoscopy, 4i Drug Response Profiling, and cell-free DNA. These technologies were applied to 240 tumor samples collected over 3 years across three cancer indications: metastatic melanoma, metastatic epithelial ovarian cancer, and acute myeloid leukemia (AML). Here, we publish the scRNA, scDNA, and bkRNA data of the melanoma cohort.

  Study EGAS50000000599

• High-resolution profile of neoantigen-specific TCR activation links moderate stimulation to increased resilience of engineered TCR-T cells

  Neoantigen-specific T cell receptors (neoTCRs) promise safe, personalized anti-tumor immunotherapy. Previously, we identified diverse neoTCRs restricted to different neoantigens in a melanoma patient. In this work, we now combined single-cell TCR- and RNA-sequencing after neoantigen-specific restimulation of peripheral blood-derived CD8+ T cells of this patient. We detected novel neoTCRs with specificity to the previously detected neoantigens and observe a heterogeneous spectrum of TCR-intrinsic activation patterns in response to a shared neoepitope ranging from previously detected higher frequent neoTCRs with moderate activation to rare ones with initially stronger activation.

  Study EGAS50000000600

• Reconstructing oral cavity tumor evolution through brush biopsy

  Oral potentially malignant disorders (OPMDs) with genomic alterations have a heightened risk of evolving into oral squamous cell carcinoma (OSCC). Currently, genomic data are typically obtained through invasive tissue biopsy. However, brush biopsy is a non-invasive method that has been utilized for identifying dysplastic cells in OPMD but its effectiveness in reflecting the genomic landscape of OPMDs remains uncertain. This pilot study investigates the potential of brush biopsy samples in accurately reconstructing the genomic profile and tumor evolution in a patient with both OPMD and OSCC. We analyzed single nucleotide variants (SNVs), copy number aberrations (CNAs), and subclonal architectures in paired tissue and brush biopsy samples. The results showed that brush biopsy effectively captured 90% of SNVs and had similar CNA profiles as those seen in its paired tissue biopsies in all lesions. It was specific, as normal buccal mucosa did not share these genomic alterations. Interestingly, brush biopsy revealed shared SNVs and CNAs between the distinct OPMD and OSCC lesions from the same patient, indicating a common ancestral origin. Subclonal reconstruction confirmed this shared ancestry, followed by divergent evolution of the lesions. These findings highlight the potential of brush biopsies in accurately representing the genomic profile of OPL and OSCC, proving insight into reconstructing tumor evolution.

  Study EGAS50000000602

• Recurrent CLTC::SYK fusions and CSF1R mutations in juvenile xanthogranuloma of soft tissue

  In this study, the genomic landscape of extracutaneous juvenile xanthogranuloma (JXG) was analyzed. By leveraging the Dutch Nationwide Pathology Databank (Palga), tumor samples were obtained from different academic medical centers in the Netherlands. The study was approved by the Palga Scientific Council and Privacy Committee (LZV-2016-183) and the Institutional Review Board of Leiden University Medical Center (B19.074). In addition, the study was approved by the Biobank and Data Access Committee of the Princess Máxima Center for Pediatric Oncology (PMCLAB2024.0512). Provided are whole transcriptome sequencing (WTS) data of 3 histiocytic tumors with CLTC::SYK fusions. WTS was performed in the routine workflow of the Princess Máxima Center for Pediatric Oncology (as described in Hehir-Kwa, et al. JCO Precis Oncol 2022). RNA was derived from formalin-fixed paraffin-embedded tumor tissue (n=1) or from frozen tumor tissue (n=2).

  Study EGAS50000000584

• Diversity of the immune microenvironment and response to checkpoint inhibitor immunotherapy in mucosal melanoma

  Mucosal melanoma (MucM) is a rare cancer with a poor prognosis and low response rate to immune checkpoint inhibition (ICI) compared to cutaneous melanoma (CM). To explore the immune microenvironment and potential drivers of MucM’s relative resistance to ICI drugs, we characterized 101 MucM tumors (43 head and neck, 31 female urogenital, 13 male urogenital, 11 anorectal, and 3 other gastro-intestinal) using bulk RNA-sequencing (RNAseq). The original publication is written by JL Vos, JJH Traets, et al. and published in JCI Insight in 2024.

  Study EGAS50000000631

• Ultra-sensitive ctDNA monitoring required for predicting response and resistance to immunotherapy in advanced melanoma

  Circulating tumor DNA (ctDNA) monitoring in peripheral blood has shown promise for disease surveillance and prognostication of ICI response. Yet even in the metastatic context, ctDNA signals can be missed, suggesting the need for increased assay sensitivity. We used a tumor-informed ctDNA assay capable of detection down to 1 part-per-million (PPM) ctDNA to profile 188 plasma samples from 23 melanoma patients receiving ICI over several years. Residual disease was detected in ctDNA over a broad range, from 130,000 PPM down to 2.3 PPM, with approximately a quarter of detections below 50 PPM. Early on-treatment increases in ctDNA level, and both ctDNA-based molecular clearance (mCR) and molecular progression (mPD) were all prognostic of both OS and PFS. Additionally, mCR consistently preceded radiographic imaging. Our results show the importance and utility of an ultra-sensitive ctDNA assay in advanced melanoma treated by ICI with potential implications for other cancers.

  Study EGAS50000000550

• Single cell multi-omics analysis of chromothriptic medulloblastoma highlights genomic and transcriptomic consequences of genome instability

  Chromothripsis is a form of genome instability, whereby a presumably single catastrophic event generates extensive genomic rearrangements of one or few chromosome(s). However, little is known about the heterogeneity of chromothripsis across different clones from the same tumor, as well as changes in response to treatment. We analyzed single-cell genomic and transcriptomic alterations linked with chromothripsis in human p53-deficient medulloblastoma (n=7). We reconstructed the order of somatic events, identified early alterations likely linked to chromothripsis and depicted the contribution of chromothripsis to malignancy. We characterized subclonal variation of chromothripsis and its effects on double-minute chromosomes, cancer drivers and putatively druggable targets. Furthermore, we highlighted the causative role and the fitness consequences of specific rearrangements in neural progenitors.

  Study EGAS00001005410

• RNA sequencing data from glioblastoma primary cell lines treated with indisulam

  This study aimed to develop NovumRNA, a bioinformatics pipeline designed to predict non-canonical tumor-specific antigens (ncTSAs) from human tumor RNA-sequencing data, potentially broadening the target pool for cancer neo-epitope-based immunotherapies. The splicing-modulating drug indisulam was investigated for its potential to induce aberrant transcriptomes, potentially increasing ncTSAs, subsequently predicted by NovumRNA. Four glioblastoma primary cell lines were derived from patient Cavitron Ultrasonic Aspirator (CUSA) material, cultured as neurospheres, and treated with indisulam or vehicle control. RNA was extracted at 6 and 16 hours post-treatment and sequenced using the NovaSeq platform. The resulting RNA-seq data was analyzed with NovumRNA, using healthy brain GTEx samples as controls, to identify and validate ncTSAs induced by indisulam treatment. NovumRNA is available at: https://github.com/ComputationalBiomedicineGroup/NovumRNA.

  Study EGAS50000000680

• Fragmentomic features of individuals with different cfDNA concentrations

  The goal of this study is to explore fragmentomic patterns that vary between individuals of different concentrations of total cell-free DNA in plasma. We have selected a large cohort of individuals (ethnically Chinese men with a median age of 54 years, IQR 49-57) who were part of a screening of a large-scale clinical study to screen for nasopharyngeal carcinoma. Differences in fragmentomic features provided insights into the modulation of cfDNA levels in blood circulation. Fragmentomic and machine learning systems adopted in this study have also been applied to assess the quantity of cfDNA species of clinical interest, including the fraction of circulating fetal and tumor DNA, from pregnancy cases and individuals with hepatocellular carcinoma, respectively.

  Study EGAS50000000692

• RNA sequencing of follicular T cell lymphoma

  Study EGAS00001004646

• WGS of CTCs enriched using high-throughout microfluidic device from entire cancer patient leukopak

  Single-cell low-pass WGS analysis (illumina platform, PE150, 1-2x coverage) was performed on CTCs enriched using high-throughout microfluidic device from entire leukopak from patients with metastatic prostate cancer (GU-1 and GU-2) and metastatic hepatocellular carcinoma (HCC-1 and HCC-2).

  Study EGAS50000000723

• RNAseq samples of patients with anti-PD-1 resistant HNSCC from a non-randomized, open-label phase 1b clinical trial

  Immune checkpoint blockade (ICB) is an effective treatment for a subset of patients with head and neck squamous cell carcinoma (HNSCC); however, the majority remain refractory. In a nonrandomized, open-label Phase 1b clinical trial, participants with recurrent and/or metastatic (R/M) HNSCC who had progressed on ICB were treated with low-dose 5-azacytidine (5-aza) daily for either 5 or 10 days, in combination with durvalumab and tremelimumab. The primary objective was to determine the biologically effective dose of 5-aza. In this study, RNA sequencing (RNA-seq) was performed on baseline and on-treatment samples from eight participants, and transcriptomic changes were analyzed to assess the impact of low-dose 5-aza treatment.

  Study EGAS50000000728

• Molecular correlates for HPV-negative head and neck cancer engraftment prognosticate patient outcomes

  Head and neck squamous cell carcinoma (HNSCC) tumors were sampled from 88 patients. Samples were implanted subcutaenously into the flank of NOD/SCID/IL2R-/- mice. Mice were then monitored weekly for tumor growth and the time of initial palpation was recorded. Mice were euthanized when tumors reached 15 mm in diameter or after 6 months. If no tumor formed by 6 months, the patient tumor was defined as Non-engrafter (N). RNA-seq was performed on all primary tumor samples and successfully engrafted patient-derived xenograft (PDX) samples.

  Study EGAS50000000714

• Distinct immune cell infiltration patterns in PDAC exhibit divergent immune cell selection and immunosuppressive mechanisms

  Pancreatic ductal adenocarcinoma has a dismal prognosis. A comprehensive analysis of single-cell multi-omic data from matched tumour-infiltrated CD45+ cells and peripheral blood in 12 patients, and two published datasets, reveals a complex immune infiltrate. Patients have either a myeloid-enriched or adaptive-enriched tumour microenvironment. Lymphocyte enrichment is intrinsically linked with highly distinct B and T cell clonal selection, diversification, and differentiation. Using TCR data, we see the largest clonal expansions in CD8 effector memory, senescent cells, and highly activated regulatory T cells which are induced within the tumour from naïve cells. We identify pathways that potentially lead to a suppressive microenvironement, including targets of immunotherapy and checkpoints including TIGIT/PVR and SIRPA/CD47. PDAC patient tumors from the APACT clinical trial revealed that patients with myeloid enrichment had the shorter overall survival compared to those adaptive cell enrichment. We identify multiple therapeutic targets that should form the basis for rational design including boosting of B cell responses, targeting immunosuppressive macrophages, and specific Treg depletion approaches. The dataset is scRNA-seq data from PDAC patients.

  Study EGAS50000000726

• Phase 1/2 Study of the Indoleamine 2,3-Dioxygenase 1 Inhibitor Linrodostat Mesylate Combined With Nivolumab or Nivolumab and Ipilimumab in Advanced Solid Tumors or Hematologic Malignancies

  Purpose: To evaluate the safety, efficacy, pharmacokinetics, pharmacodynamics, and biomarker data of linrodostat mesylate, a selective, oral indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor, combined with nivolumab ± ipilimumab in advanced solid tumors and hematologic malignancies. Patients and Methods: In this phase 1/2 study, patients received once-daily (QD) linrodostat (part 1 [escalation], 25-400 mg; part 2 [expansion], 100 or 200 mg) plus nivolumab (480 mg every [Q] 4 weeks [W] or 240 mg Q2W) or triplet therapy (part 3, linrodostat 20-100 mg QD; nivolumab 360 mg Q3W or 480 mg Q4W; ipilimumab 1 mg/kg Q6W or Q8W). Endpoints included safety and efficacy (co-primary; parts 2, 3), pharmacokinetics, pharmacodynamics, biomarkers, and efficacy (part 1). Results: Fifty-five, 494, and 41 patients were enrolled in parts 1, 2, and 3, respectively. Linrodostat exposures exceeded predicted therapeutic target concentrations starting at 50 mg. Rates of grade 3/4 adverse events were 50.1%-63.4%. The maximum tolerated linrodostat dose was 200 mg; dose-limiting toxicities were primarily immune related. Responses were observed across different cohorts, study parts, and tumor types, particularly in immunotherapy-naive patients. Kynurenine decreased with linrodostat + nivolumab, regardless of response. In contrast, interferon gamma (IFN-γ) gene expression signature was associated with response; in nonmelanoma patients, a composite of low tryptophan 2,3-dioxygenase (TDO2) gene expression plus high IFN-γ signature was associated with response. Conclusions: Linrodostat + nivolumab ± ipilimumab demonstrated a manageable safety profile. Kynurenine changes supported IDO1 pathway inhibition but did not correlate with response. A composite biomarker of low TDO2 expression plus high IFN-γ gene expression may predict response to linrodostat + nivolumab.

  Study EGAS50000000710

• 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