4055 results for "*oma"

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• Predictor_ChemoNEAR_TNBC

  In this study a collection of core biopsies from breast cancer patients receiving neoadjuvant chemotherapy as part of the ChemoNEAR trial will be investigated. The study is intended to detect early acquired resistance in women with diagnosed breast carcinoma. Samples will undergo whole genome sequencing and analysis, including use of HR Predict.

  Study EGAS00001002806

• Angiosarcoma_follow_up_2_validation_study

  A bespoke targeted pulldown experiment will be performed on patients with Angiosarcoma. the resulting products will be sequenced to determine the prevalence of previously found mutations in these patients.

  Study EGAS00001000518

• Discovery_of_resistance_mechanisms_to_the_BRAF_inhibitor_vemurafenib_in_metastatic_BRAF_mutant_melanoma

  Discovery of resistance mechanisms to the BRAF inhibitor vemurafenib in metastatic BRAF mutant melanoma by massively-parallel sequencing of tumour samples. Comparison of genomic characteristics of pretreatment ‘sensitive’ to recurrence ‘resistant’ tumours to identify the genetics of drug resistance.

  Study EGAS00001000551

• Integrative genomic and transcriptomic analysis of adult leiomyosarcoma (HIPO-028, HIPO-018, HIPO-021)

  Leiomyosarcoma (LMS) is an aggressive mesenchmyal malignancy with few therapeutic options. The mechanisms underlying LMS development, including clinically actionable genetic vulnerabilities, are largely unknown. We performed genomic and transcriptomic profiling of a large cohort of LMS tumors and identified substantial mutational heterogeneity, near-universal inactivation of TP53 and RB1, widespread DNA copy number alterations, chromothripsis, and frequent whole-genome duplication. Furthermore, we discovered recurrent alterations in telomere maintenance genes such as ATRX, RBL2, and RPA1, resulting in alternative lengthening of telomeres in 78% of cases. Finally, most tumors displayed hallmarks of “BRCAness”, including alterations in various homologous recombination DNA repair genes, multiple structural rearrangements, and enrichment of specific mutational signatures, and cultured LMS cells were sensitive towards olaparib and cisplatin treatment. This first comprehensive study of genetic alterations in LMS has uncovered key biological features that may inform future experimental research and enable the design of novel therapeutic strategies for this disease.

  Study EGAS00001002437

• Chondromyxoid_fibroma

  Chondromxoid fibroma is a benign tumour of bone with unknown underlying pathogenesis. To determine pathognomic genomic event in chondromyxoid fibroma whole genome sequencing will be undertaken to reconstruct rearrangements and find underlying mutations.

  Study EGAS00001000533

• Cell fate mapping of human glioblastoma reveals an invariant stem cell hierarchy pre- and post-treatment

  Human glioblastomas (GBMs) are thought to harbour a subpopulation of glioblastoma stem cells (GSCs) that initiate tumour formation and regrowth following treatment. However, the origin of their proliferative heterogeneity during tumour growth pre- and post-treatment remains poorly understood. Here we study the clonal evolution of DNA barcoded GBMs following their serial propagation in xenograft mouse models to define the fate behaviour of individual GBM cells. Through quantitative analysis of clone sizes scored across multiple passages, we show that the growth of GBM clones in vivo are consistent with a remarkably neutral process resulting from a conserved proliferative hierarchy. In this model, slow-cycling stem-like cells give rise to a more rapidly cycling progenitor population with extensive self-maintenance capacity, that in turn generates short-lived cells that lack proliferative ability. We also identify rare "outlier" clones that deviate from these dynamics, and further show that chemotherapy reproducibly facilitates the selective expansion of pre-existing drug-resistant GBM lineages. Finally, we show that coexisting, functionally distinct GSCs may be targeted separately with epigenetic compounds. These findings show that, independent of an evolving mutational signature, the clonal dynamics of human GBM can be surprisingly robust, with intratumoural heterogeneity derived primarily from the defined stochastic fate behaviour of tumour cells within a conserved proliferative hierarchy.

  Study EGAS00001002424

• Successful immune checkpoint blockade in a patient with advanced stage microsatellite unstable biliary tract cancer (H021)

  Cancers acquire multiple somatic mutations that can lead to the generation of immunogenic mutation-induced neoantigens. These neoantigens can be recognized by the host’s immune system. However, continuous stimulation of immune cells against tumor antigens can lead to immune cell exhaustion, which allows uncontrolled outgrowth of tumor cells. Recently, immune checkpoint inhibitors have emerged as a novel approach to overcome immune cell exhaustion and re-activate anti-tumor immune responses. In particular, antibodies blocking the exhaustion-mediating programmed death receptor (PD-1)/PD-L1 pathway have shown clinical efficacy. The effects were particularly pronounced in tumors with DNA mismatch repair deficiency and a high mutational load, which typically occur in the colon and endometrium. Here, we report on a 24-year old woman diagnosed with extrahepatic cholangiocarcinoma who showed strong and durable response to the immune checkpoint inhibitor pembrolizumab, although treatment was initiated at an advanced stage of disease. The patient’s tumor displayed DNA mismatch repair deficiency and microsatellite instability (MSI), but lacked other features commonly discussed as predictors of response towards checkpoint blockade, such as PD-L1 expression or dense infiltration with cytotoxic T cells. Notably, high levels of HLA class I and II antigen expression were detected in the tumor, suggesting a potential causal relation between functionality of the tumor’s antigen presentation machinery and the success of immune checkpoint blockade. We suggest determining MSI status in combination with HLA class I and II antigen expression in tumors potentially eligible for immune checkpoint blockade even in the absence of conventional markers predictive for anti-PD-1/PD-L1 therapy and in entities not commonly linked to MSI phenotype. Further studies are required to determine the value of these markers for predicting the success of immune checkpoint blockade. (H021)

  Study EGAS00001002441

• ICGC PedBrain DNA methylation sequencing

  DNA methylation profiling of 107 medulloblastoma and 8 control samples by high-coverage whole-genome bisulfite (WBGS) sequencing and Illumina Infinium HumanMethylation450k array.

  Study EGAS00001000561

• ICGC medulloblastoma whole genome sequencing data, ICGC release 16

  ICGC medulloblastoma whole genome sequencing data, ICGC release 16

  Study EGAS00001000744

• Angiosarcoma_whole_exome

  Extension of angiosarcoma whole genome sequencing study

  Study EGAS00001000588