5524 results for "*oma"

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• DAC for hepatoblastoma sequencing data

  Data Access Committee for sequencing data of hepatoblastoma PDX cell models sequenced under University of Helsinki.

  Dac EGAC50000000548

• Genomic Copy-Number Variants Drive Apoptotic Resistance and Relapses on Immune Checkpoint Inhibitors

  We investigated the genomic mechanisms underlying acquired resistance (AR) to immune checkpoint inhibitors (ICIs) across tumor types, specifically by examining how copy number variant (CNV)-driven subclonal evolution contributes to clinical relapses in melanoma patients. We analyzed longitudinal clinical melanoma samples from patients who experienced relapses on ICI therapy, complemented by isogenic human melanoma cell line models (M486) and murine melanoma tumor systems. Single-cell whole-genome sequencing (scWGS) was employed to resolve subclonal CNV patterns in AR tumors. The scWGS data revealed that AR-dominant subclones systematically deleted pro-apoptotic genes while amplifying anti-apoptotic genes and innate resistance pathway components. Notably, shared and private AR subclonal CNVs preexisted selective pressure, with convergent evolution targeting apoptosis-regulatory pathways and resulting in downregulated apoptotic/mitochondrial priming that enables ICI resistance. scWGS datasets from isogenic human melanoma cell lines, patient-matched tumor samples, and murine melanoma models will be made available through dbGaP, enabling researchers to access high-resolution subclonal CNV profiles that define the genomic landscape of acquired ICI resistance evolution.

  Study phs004102

• Dynamic Evolution of Fibroblasts Revealed by Single Cell RNA Sequencing of Human Pancreatic Cancer

  Understanding the constituents of the pancreatic ductal adenocarcinoma (PDAC) microenvironment may illuminate more efficacious targets for treating this aggressive malignancy. However, the compositional changes occurring in untreated and treated PDAC relative to both normal and inflamed pancreas have not been well characterized. To provide a more comprehensive understanding of the PDAC tumor microenvironment relative to the non-cancerous pancreas, we performed single-cell expression profiling (10X Genomics Chromium) on samples of upfront resectable PDAC, FOLFIRINOX-based treated PDAC, chronic pancreatitis, and normal pancreas specimens from 19 patients. Spatial gene expression profiling (10X Genomics Visium) was performed to gain additional insight into cell populations. Our analysis revealed that fibroblasts are central mediators of cell-cell communication in both inflamed and malignant settings and defined unique roles for these cell populations in different disease contexts.

  Study phs003751

• Molecular Correlatives from SU2C-SARC032

  SU2C-SARC032 was a phase II international, randomized trial for patients with localized, high-risk undifferentiated pleomorphic sarcoma or dedifferentiated or pleomorphic liposarcoma of the extremity and limb girdle. On the trial, the addition of perioperative pembrolizumab to preoperative radiotherapy and surgery improved disease-free survival compared to preoperative radiotherapy and surgery alone. Bulk RNA-sequencing was performed on pre-treatment and surgically resected tumor specimens.

  Study phs003921

• A Therapeutic Vaccine for Fibrolamellar Hepatocellular Carcinoma

  Fibrolamellar hepatocellular carcinoma (FLC) is a rare form of liver cancer affecting 33 children and young adults that is driven by a chimeric protein, DNAJ-PKAc. We conducted a phase 1 clinical trial of a therapeutic vaccine targeting DNAJ-PKAc 38 (FLC-Vac), in combination with nivolumab and ipilimumab, in children and adults with advanced FLC. Among 16 patients enrolled, 12 completed the vaccine priming phase and were evaluable for both immunological and clinical endpoints. Grade 3 treatment-related adverse events were reported by six patients (37.5%). DNAJ43 PKAc-specific T cell responses were detected in 9/12 patients after treatment. In the subset of patients who completed the initial priming phase the disease control rate (DCR) was 75% (9/12), with three partial responses (25%). All patients with clinical responses also had DNAJ-PKAc specific T cell responses, from which we identified multiple class II-restricted T cell receptors (TCRs) with specificity for DNAJ-PKAc. Correlates of response included both functional neoantigen reactivity and changes in TCR repertoire features over time. Immune escape in two patients corresponded with immune exhaustion rather than neoantigen escape or HLA loss.

  Study phs003970

• Deciphering the aggressive nature of morphoeic basal cell carcinoma

  Morphoeic basal cell carcinoma (mBCC) has a high risk of local recurrence compared to the more indolent nodular subtype reflected by a different set of driver mutations including FLNB and HECTD4. Surrounding mBCC stroma is abnormal, containing mutations such as EPHA3. Hedgehog pathway over-expression is seen in both the tumour and stroma of morphoeic tissue with the latter potentially being partly responsible for its aggressive nature and risk of recurrence.

  Study EGAS00001001915

• Comprehensive genetic landscape, immune checkpoint profiling, and establishment of patient-derived xenograft (PDX) of metachronous brain tumors from constitutive mismatch repair deficiency with a biallelic variant on MSH6

  Constitutional mismatch repair deficiency (CMMRD) syndrome is a rare genetic disorder caused by biallelic pathogenic variants in mismatch repair genes (PMS2, MSH6, MLH1, or MSH2) resulting in the development of a variety of different tumors, including brain neoplasms. This study molecularly characterized a Brazilian child with CMMRD, harboring two metachronous brain tumors (medulloblastoma and high-grade glioma), and established a patient-derived xenograft (PDX) of the CMMRD-associated brain tumor. Keywords: Brazil, Constitutional mismatch repair deficiency syndrome, exome, MSH6, medulloblastoma, high-grade glioma.

  Study EGAS50000000351

• TTFields Glioblastoma Data Access Committee, Charité – Universitätsmedizin Berlin

  This Data Access Committee is responsible for reviewing and approving data access requests for genomic and associated clinical data from patients with glioblastoma, IDH wildtype, treated with surgery, standard chemoradiotherapy and Tumor Treating Fields at Charité – Universitätsmedizin Berlin. The DAC ensures that any data use is consistent with the patients’ informed consent, the study’s ethical approval and applicable data protection regulations. Approved applicants may use the data only for biomedical research on brain tumours and related methods, must not attempt re-identification of participants, and may not share the data with unauthorized third parties

  Dac EGAC50000000843

• DAC for study CMMRD–associated high-grade glioma

  This Data Access Committee (DAC) is responsible for de-identified, summarized somatic variant call data derived from paired tumor–blood Whole-exome sequencing of human samples in a glioma research study. Access requests are approved without additional restrictions and are granted solely for health-related research purposes.

  Dac EGAC50000000855

• Relapse CHL study

  Classical Hodgkin Lymphoma (CHL) is characterized by a complex tumor microenvironment (TME) that supports disease progression. While immune cell recruitment by Hodgkin and Reed–Sternberg (HRS) cells is well-documented, the role of non-malignant B cells in relapse remains unclear. Using single-cell RNA sequencing (scRNA-seq) on paired diagnostic and relapsed CHL samples, we identified distinct shifts in B cell populations, particularly an enrichment of naïve B cells and a reduction of memory B cells in early-relapse compared to late-relapse and newly diagnosed CHL. The enrichment of naïve B cells in early relapse biopsies was confirmed in independent validation cohorts using scRNA-seq and immunohistochemistry. Notably, naïve B cells in early-relapse samples exhibited high expression of LGALS9, an immunosuppressive molecule known to interact with T cell immunoglobulin and mucin domain 3 (TIM-3) on regulatory T cells (Tregs). Cell-cell interaction analysis revealed the importance of interactions between LGALS9+ naïve B cells and TIM-3+ Tregs in the early-relapse setting. Spatial analysis by imaging mass cytometry confirmed close proximity of LGALS9+ naïve B cells with TIM-3⁺ CD4⁺ T cells and HRS cells, pointing to their role in shaping an immunosuppressive niche. Our findings highlight a previously unrecognized population of LGALS9⁺ naïve B cells with immunoregulatory potential in early-relapse CHL and provide new insights into the spatial and transcriptional architecture of the relapsed TME in CHL.

  Study EGAS00001008222