4836 results for "*oma"

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• Whole-exome sequencing of intravascular large B-Cell lymphoma

  Intravascular large B-cell lymphoma (IVLBCL) is a unique form of diffuse large B-cell lymphoma (DLBCL) characterized by extranodal cell growth especially in small vessels without systemic lymphadenopathy. The limitation in obtaining sufficient tumor materials hampers understanding the molecular pathogenesis of IVLBCL. We performed whole-exome sequencing of IVLBCL using plasma-derived cell-free DNA (cfDNA) and patient-derived xenograft (PDX) samples.

  Study EGAS00001003970

• The mutational landscape of primary central nervous system lymphoma (Hipo H050, A050, XD013)

  ]Primary lymphomas of the central nervous system (PCNSL) are diffuse large B-cell lymphomas (DLBCLs) which are confined to the central nervous system (CNS). Despite extensive research, the molecular alterations leading to PCNSL have not been fully elucidated. In order to provide a comprehensive description of the mutational landscape in PCNSL, we here performed integrative whole genome and transcriptome sequencing analysis of 51 lymphomas presenting in the CNS, including 42 EBV-negative PCNSL, 6 secondary CNS lymphomas (SCNSL) and 3 EBV+ CNSL.

  Study EGAS00001005339

• Single cell exome sequencing of lung adenocarcinoma

  Single cell exome sequencing was performed on 200 single cells isolated from a lung adenocarcinoma, female, non-smoker patient. The cells were derived from two distant tumour sectors and a far normal sector. The single cells were amplified on the Fluidigm C1 machine using the GE Healthcare illustra GenomiPhi V2 DNA Amplification Kit prior to sequencing library preparation. In addition, bulk exome sequencing was also conducted for each tumour sectors. For this study, somatic variations were detected from the single cells and phylogenetic clustering was conducted to elucidate the evolutionary trajectory of lung cancer.

  Study EGAS00001002972

• Myeloma WGS

  Most patients with multiple myeloma (MM) die from progressive disease after relapse. To advance our understanding of MM evolution mechanisms, we performed whole-genome sequencing of 80 tumour-normal newly diagnosed pairs and 24 matched relapse tumours from the Myeloma XI trial.

  Study EGAS00001004000

• Tumor-specific expression of let-7i and miR-192 is associated with resistance to cisplatin-based chemoradiotherapy in patients with larynx and hypopharynx cancer

  Background: The majority of patients with locally advanced larynx or hypopharynx squamous cell carcinoma are treated with organ preserving chemoradiotherapy (CRT). Clinical outcome following CRT varies greatly. We hypothesized tumor microRNA (miRNA) expression is predictive for outcome following CRT. Methods: Next-generation sequencing (NGS) miRNA profiling was performed on 37 formalin fixed paraffin embedded (FFPE) tumor samples. Patients with a recurrence free survival (RFS) of less than 2 years (“poor outcome”) and patients without recurrence within 2 years (“good outcome”) were compared by differential expression analysis. Tumor-specific miRNAs were selected based on normal mucosa miRNA expression data from The Cancer Genome Atlas database. A model was constructed to predict outcome using group-regularized penalized logistic ridge regression. Candidate miRNAs were validated in the initial sample set by RT-qPCR as well as in 46 additional tumor samples.Results: 1,938 known mature miRNAs were detected. Thirteen miRNAs were differentially expressed (p<0.05, FDR<0.1) according to outcome group. Initial class prediction in the NGS cohort (n=37) resulted in a model combining five miRNAs and disease stage, able to predict CRT outcome with an area under the curve (AUC) of 0.82. In the RT-qPCR cohort (n=83), 25 patients (30%) experienced early recurrence (median RFS 8 months; median follow-up 42 months). Class prediction resulted in a model combining let-7i-5p and miR-192-5p and disease stage, able to discriminate with an AUC of 0.80 patients with good versus poor clinical outcome.Conclusion: The combined miRNA expression and disease stage prediction model is superior to using either factor alone. ¬¬¬This study indicates NGS miRNA profiling using FFPE specimens is feasible, resulting in clinically relevant biomarkers.

  Study EGAS00001004001

• Mongolia Western HCC

  Mongolia has the world’s highest incidence of hepatocellular carcinoma (HCC), with ~100 cases/105 inhabitants. We molecularly characterize the Mongolian (n=192) compared to Western HCCs (n=187) by RNA-seq and WES. Mongolian patients were predominantly younger, female, with HBV-HDV non-cirrhotic livers. Mongolian HCCs had higher rates of protein-coding mutations (121 vs 70 mut /tumor in West), and mutations in known (i.e. APOB) and putative HCC drivers (TSC2). A novel mutational signature (SBS Mongolia) was identified in 25% of cases associated with the carcinogenic DMS genotoxic signature. Two unique molecular classes enriched in HBV-HDV infection, female gender and inflamed tumors are described.

  Study EGAS00001005364

• Host whole genome variations are associated with neurocognitive outcome in survivors of pediatric medulloblastoma

  Host whole genome analysis is a promising source of predictive information for long-term morbidity in cancer survivors. However, studies on genetic predictors of long-term outcome, particularly neurocognitive function following chemoradiation in pediatric oncology are limited. In the present study, we evaluated variations in host whole genome single nucleotide polymorphisms (SNPs) and their association with cognitive outcome. Whole-genome SNP analysis of host peripheral blood was conducted on 22 medulloblastoma long-term survivors, of whom 18 completed neuropsychological testing. First, unsupervised consensus clustering of the most variable SNPs within 409 genes involved in DNA repair was performed. Discrete variant groups were identified, although they were not associated with cognitive outcome, suggesting that variations in genes corresponding to a single functional group may be insufficient to predict long-term outcome alone. In support of this interpretation, unsupervised hierarchical clustering analysis using disease-associated gene variants by cognitive impairment status yielded two distinct variant clusters comprised of 36 variants, 34 of which were in noncoding regions. These findings illustrate for the first time that cognitively impaired survivors have a distinct variant profile compared to other medulloblastoma survivors. Future research in larger cohorts is needed to validate host genome predictors of cognitive impairment that may impact clinical management.

  Study EGAS00001002996

• Multi-omics of Richter syndrome

  Richter syndrome (RS) is the aggressive transformation of Chronic Lymphocytic Leukemia, mostly with Diffuse Large B-Cell Lymphoma histology. While histologically similar, RS and de novo DLBCLs present with different clinical courses. We characterized the RS epigenome by combining genome-wide DNA methylation with transcriptome-sequencing on a large RS cohort.

  Study EGAS00001005495

• Analysis of RAD51C promoter methylation using targeted bisulfite sequencing (amplicon sequencing) in ovarian cancer pre-clinical models and patient samples.

  In high-grade serous ovarian carcinoma (HGSC), deleterious mutations in the DNA repair gene RAD51C are established drivers of defective homologous recombination and are emerging biomarkers of PARP inhibitor (PARPi) sensitivity. RAD51C promoter methylation (meRAD51C) is detected at similar frequencies to mutations, yet its effects on PARPi responses remain unresolved. In this study, three HGSC patient-derived xenograft (PDX) models with methylation at most or all examined CpG sites in the RAD51C promoter show responses to PARPi. Both complete and heterogeneous methylation patterns were associated with RAD51C gene silencing and homologous recombination deficiency (HRD). PDX models lost meRAD51C following treatment with PARPi rucaparib or niraparib, where a single unmethylated copy of RAD51C was sufficient to drive PARPi resistance. Genomic copy number profiling of one of the PDX models using SNP arrays revealed that this resistance was acquired independently in two genetically distinct lineages. In a cohort of 11 patients with RAD51C-methylated HGSC, various patterns of meRAD51C were associated with genomic 'scarring', indicative of HRD history, but exhibited no clear correlations with clinical outcome. Differences in methylation stability under treatment pressure were also observed between patients, where one HGSC was found to maintain meRAD51C after 6 lines of therapy (4 platinum-based), whilst another HGSC sample was found to have heterozygous meRAD51C and elevated RAD51C gene expression (relative to homozygous meRAD51C controls) after only neo-adjuvant chemotherapy. As meRAD51C loss in a single gene copy was sufficient to cause PARPi resistance in PDX, methylation zygosity should be carefully assessed in previously treated patients when considering PARPi therapy.

  Study EGAS00001005395

• Cell type-specific transcriptomics of esophageal adenocarcinoma as a scalable alternative for single cell transcriptomics

  We developed a protocol for the separation of esophageal carcinoma tissue into leukocytes (using CD45 as a marker), epithelial cells (EpCAM), and fibroblasts (two out of PDGFRA, CD90, anti-fibroblast) by fluorescence-activated cell sorting followed by RNA-sequencing

  Study EGAS00001004053