5250 results for "*oma"

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• 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

• Blood-based monitoring of relapsed/refractory cHL patients predict responses to PD-1 blockade treatment

  Hodgkin lymphoma (cHL) patients are uniquely susceptible to treatment with programmed cell death-1 (PD-1) treatment. However, monitoring with FDG-PET/CT, the current response detection standard, is challenging. Here, we address the potential applicability of tissue biomarkers and blood-based biomarkers in PD-1 treated cHL patients. We evaluated 9p24.1/PD-L1/PD-L2 alterations, and expression of PD-L1 and antigen presentation molecules (HLA class I/II) in 9 tissue biopsies of 4 patients. In addition, we assessed circulating tumor DNA (ctDNA), extracellular vesicle associated miRNAs (EV-miRNAs), soluble PD-L1 and serum TARC (sTARC) in 26 longitudinal blood samples of these patients during PD-1 treatment. We found that the predictive power of tissue biomarkers is dependent on the timing of the biopsy . The dynamics of blood-based biomarkers: sTARC, EV-miRNAs and ctDNA corresponded well immunotherapy treatment response. Therefore, blood-based biomarkers are promising monitoring strategies in PD-1 treated cHL patients and should be further explored in clinical trials or observational studies.

  Study EGAS00001005894

• Diagnostic Genomic Analysis is Prognostic in AYA ALL Patients Treated on a MRD-Stratified Paediatric Protocol

  Background: Over the last decade, next generation sequencing has enabled classification of multiple new recurrent genomic drivers of acute lymphoblastic leukemia (ALL). We provide a comprehensive genomic survey of adolescent and young adult (AYA) patients treated on the Australasian Leukaemia and Lymphoma Group (ALLG) ALL06 study. ALL06 clinical trial described the efficacy and tolerability of AYA ALL patients aged 15-39 years treated on a single minimal residual disease (MRD)-stratified platform. In this study we have taken the ALL06 cohort and retrospectively performed comprehensive genomic analyses assessing response of AYA patients with various genomic subtypes treated with a paediatric approach. Methods: Genomic risk classification of B- and T-ALL patients (n=57) enrolled to the study was based on mRNA-Sequencing, MLPA, immunophenotyping and cytogenetics. Results: Using this approach, 36/40 (90%) B- and 13/17 (76.5%) T-ALL patients were classified according to genomic risk. We have linked outcome data with each patient’s genomic risk and found a strong correlation between adverse genomic risk and MRD at the end of consolidation, translating to inferior overall and relapse free survival. Patients with adverse risk genomics who achieved negative MRD status had improved responses compared to those with persistent MRD. Patients with standard risk genomics had excellent responses regardless of their MRD status. Conclusion: Our data argue strongly for incorporation of a genomic risk classification into future ALL treatment paradigms at the time of diagnosis.

  Study EGAS50000000752

• Assessment of candidate high-grade serous ovarian carcinoma predisposition genes through integrated germline and tumour sequencing

  High-grade serous ovarian carcinoma (HGSOC) has a significant hereditary component, only half of which is explained. Previously, we performed germline exome sequencing on BRCA1 and BRCA2-negative HGSOC patients, revealing three proposed and 43 novel candidate genes enriched with rare loss-of-function variants. For validation, we undertook case-control analyses using genomic data from disease-free controls. This confirms enrichment for nearly all previously identified genes. Additionally, one-hundred-and-eleven HGSOC tumours from variant carriers were sequenced alongside other complementary studies, seeking evidence of biallelic inactivation as supportive evidence. PALB2 and ATM validate as HGSOC predisposition genes, with 6/8 germline carrier tumours exhibiting biallelic inactivation accompanied by characteristic mutational signatures. Among candidate genes, only LLGL2 consistently shows biallelic inactivation and protein expression loss, supporting it as a novel HGSOC susceptibility gene. The remaining candidate genes fail to validate. Integrating case-control analyses with tumour sequencing is thus crucial for accurate gene discovery in familial cancer studies.

  Study EGAS50000000770

• A Phase Ib/II Study of Regorafenib and Paclitaxel in Beyond First-line Advanced Esophagogastric Carcinoma (REPEAT)

  Regorafenib showed promising results in gastric cancer. We aimed to assess the tolerability of regorafenib and paclitaxel in advanced esophagogastric cancer (EGC) patients refractory to first-line treatment and explore potential biomarkers.. We performed enzyme-linked immunosorbent assay measurements of galectin-1, RNA sequencing, and shallow wholegenome sequencing of metastatic tumor biopsies for biomarker analyses.

  Study EGAS00001006054

• Tumor-reactive heterotypic CD8 T cell clusters from clinical samples

  Emerging evidence suggests a correlation between CD8+ T cell-tumor cell proximity and anti-tumor immune response. However, it remains unknown whether these cells exist as functional clusters that can be isolated from clinical samples. By conventional and imaging flow cytometry, we show here that from 21/21 human melanoma metastases, we could isolate heterotypic clusters, comprising CD8+ T cells interacting with one or more tumor cells and/or antigen-presenting cells (APCs). Single-cell RNA-sequencing revealed that T cells from clusters were enriched for gene signatures associated with tumor reactivity and exhaustion. Clustered T cells exhibited increased TCR clonality indicative of expansion, while TCR-matched T cells showed more exhaustion and co-modulation when conjugated to APCs than to tumor cells. T cells that were expanded from clusters ex vivo exerted on average 9-fold increased killing activity towards autologous melanomas, which was accompanied by enhanced cytokine production. Upon adoptive cell transfer into mice, T cells from clusters showed improved patient-derived melanoma control, which was associated with increased T cell infiltration and activation. Together, these results demonstrate that tumor-reactive CD8+ T cells are enriched in functional clusters with tumor cells and/or APCs and that they can be isolated and expanded from clinical samples. Typically excluded by single cell gating in flow cytometry, these distinct heterotypic T cell clusters serve as a valuable source to decipher functional tumor-immune cell interactions, while they may also be therapeutically explored.

  Study EGAS50000000785

• 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. We identified a panel of genes that were over- or under-expressed in symptomatic states that could be putative oncogenic drivers or tumor suppressors, respectively.

  Study EGAS50000000803

• Measles oncolytic virus as an immunotherapy for recurrent/refractory pediatric medulloblastoma and atypical teratoid rhabdoid tumor

  Pediatric recurrent medulloblastoma (MB) and atypical teratoid rhabdoid tumor (ATRT) are largely incurable and warrant novel therapies. We investigated a) the safety of a measles virus variant, MV-NIS, in a pediatric phase 1 study and b) the mechanisms of MV-NIS and potential benefit of combination with immune checkpoint inhibition (ICI). Pediatric patients with recurrent MB or ATRT were treated with intratumoral injections for local recurrence or via lumbar puncture for disseminated recurrence. We evaluated local immune responses to MV-NIS with and without ICI via single-cell and bulk RNA sequencing in an intracranial, immunocompetent, syngeneic murine model. MV-NIS given intratumorally or via repeat intrathecal dosing was safe. MV-NIS prolonged survival in murine models but did not demonstrate additive benefit with ICI. No changes in tumor-infiltrating immune-cell composition or activation were observed in response to MV-NIS treatment; however, MV-NIS induced local expression of neutralizing antibodies, complement cascade, and phagocytosis-related genes.

  Study EGAS50000000811

• Integrative analysis reveals a macrophage-predominant, immunosuppressive immune microenvironment and subtype-specific therapeutic vulnerabilities in advanced salivary gland cancer

  Background Salivary gland cancers (SGC) are rare and heterogeneous malignant tumors. Advanced SGC lack established treatment options and show poor response to immunotherapy. Here, an integrative multi-omics analysis in a large cohort of advanced SGC revealed insights into the tumor immune microenvironment (TIM) and distinct mechanisms of immune evasion. Methods A total of 104 patients with recurrent/metastatic SGC from the DKTK MASTER program were included in this study. Whole-exome or whole-genome sequencing and RNA-sequencing was performed on fresh frozen tumor tissue. The tumor immune microenvironment was analyzed using CIBERSORT deconvolution analysis and immune gene expression scores in bulk RNA-sequencing data. Single-nuclei sequencing and immunohistochemistry analyses were performed in selected samples. Results were validated in bulk RNA-sequencing data of a previously published independent dataset. Results Bulk transcriptome analysis revealed an immune-deserted TIM in the majority of advanced SGC samples. Immune exclusion was most prominent in adenoid cystic carcinoma (ACC) subgroup 1 exhibiting a downregulation of the antigen processing machinery. Only a small subset of advanced SGC, including few adenoid cystic carcinoma, exhibited T-cell inflammation, which was correlated with tumor mutational burden in Non-ACC samples. Subtype specific expression of immune checkpoints as well as cancer testis antigens were identified with prominent expression of VTCN1 in luminal cells within ACC. Single-cell RNA-sequencing and bulk RNA-seq deconvolution analysis validated immune cell exclusion and revealed a TIM that was dominated by M2 macrophages across SGC subtypes. Among evaluable patients treated with immune checkpoint inhibitors, a high T-cell to macrophage ratio was associated with clinical benefit. Conclusions These data support biomarker-based development of immune-checkpoint inhibition and the development of novel immune-checkpoint inhibitors and cellular therapies in SGC.

  Study EGAS50000000809

• Whole Exome Sequencing of a Lung Adenocarcinoma Patient Across Three Time Points

  A 65-year-old female patient with a significant smoking history (40 pack-years) was first diagnosed with lung adenocarcinoma (LUAD) in the left lung in May 2020 (L1-T1). One year later, in May 2021, the patient progressed with a new LUAD in the right lung (L1-T2) and in May 2024, another LUAD emerged in the right lung (L1-T3). Whole Exome Sequencing (WES) analysis was conducted on three tumor biopsies obtained at different time points from the same patient to investigate clonal trajectories.

  Study EGAS50000000812