4830 results for "*oma"

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• Orthotopic Patient-Derived Xenografts of Pediatric Solid Tumors

  Pediatric solid tumors arise from endodermal, ectodermal, or mesodermal lineages. Although the overall survival of children with solid tumors is 75%-80%, that of children with recurrent disease is below 30%. To capture the complexity and diversity of pediatric solid tumors and establish new models of recurrent disease, we developed a protocol to produce orthotopic patient-derived xenografts (O-PDXs) at diagnosis, recurrence, and autopsy. Tumor specimens were received from 168 patients, and 64 O-PDXs were established for 12 types of pediatric solid tumors. The origins of the O-PDX tumors were reflected in their gene-expression profiles and epigenomes. Genomic profiling of the tumors, including detailed clonal analysis, was performed to determine whether the clonal population in the xenograft recapitulated the patient’s tumor. We identified several drug vulnerabilities and showed that the combination of a WEE1 inhibitor (AZD1775), irinotecan, and vincristine can lead to complete response in multiple rhabdomyosarcoma O-PDX tumors in vivo.

  Study EGAS00001002528

• Single-cell RNA-seq of immune cells sorted from human melanoma tumors

  Tumor immune cell compositions play a major role in response to immunotherapy but the heterogeneity and dynamics of immune infiltrates in human cancer lesions remain poorly characterized. Here we identify conserved intratumoral CD4 and CD8 T cell behaviors in scRNA-seq data from 25 melanoma patients. We discover a large population of CD8 T cells showing continuous progression from an early effector "transitional" into a dysfunctional T cell state. CD8 T cells that express a complete cytotoxic gene set are rare, and TCR sharing data suggest their independence from the transitional and dysfunctional cell states. Notably, we demonstrate that dysfunctional T cells are the major intratumoral proliferating immune cell compartment and that the intensity of the dysfunctional signature is associated with tumor-reactivity. Our data demonstrate that CD8 T cells previously defined as exhausted, are in fact a highly proliferating, clonal and dynamically differentiating cell population within the human tumor microenvironment.

  Study EGAS00001003363

• Whole genome sequencing of Ewings Sarcoma

  Sarcomas are cancers of the bone and soft tissue often defined by their gene fusions. However, the timing, context, and processes by which these pathogenic fusions arise are unknown. We explored this in Ewing sarcoma, a cancer driven by EWSR1-ETS fusions, with very few cooperating mutations. Combining whole-genome sequencing with enhanced informatics, we found that the EWSR1-ETS fusion arose from striking rearrangement clusters in 42% of cases (52/124). Notably, these were organized in loops that universally contained the fusion at their center, while also weaving up to 18 genes together with it. We found the same pattern of rearrangements in three additional types of sarcoma. From these data, we define a new signature for sarcoma fusions that precedes other somatic changes, in the earliest replicating DNA of the genome. This dramatic, sudden process impinges on many genes – generating multiple coding changes that profoundly affect the transcriptome, with the disease-defining gene fusion at its core. These rearrangement loops emerge in an early ES clone from which both the primary tumor and the lethal relapse emerged, and then evolved in parallel until clinically detected.

  Study EGAS00001003385

• Deciphering Intratumoral Molecular Heterogeneity in Clear Cell Renal Cell Carcinoma with a Radiogenomics Platform

  Intratumoral heterogeneity (ITH) challenges the molecular characterization of clear cell renal cell Carcinoma (ccRCC) with percutaneous biopsies and is a confounding factor in selection of molecular-targeted versus immune-based therapy. Magnetic Resonance (MR) Imaging can noninvasively assess the spatial landscape of the entire tumor. To validate MRI for ITH assessment, we implemented a radiogenomic platform through a systematic imaging based co-localization approach for multi region tissue acquisition from single tumors. We investigated if the spatial changes in imaging can predict the molecular changes using transcriptome and histopathological correlatives. Our study confirmed imaging heterogeneity as a predictor of molecular heterogeneity in ccRCC.

  Study EGAS00001003846

• Analysis of four key cell types (epithelial, fbroblast, myeloid and T cells)

  Alterations of the normal prostate epithelial cell genome trigger the emergence of carcinoma, however cancer-only analyses of genomic aberrations have resulted in little clinical translation. A deep understanding of the tumor microenvironment is likely to inform on key drivers of disease progression and novel therapeutic opportunities. We investigated the role of key cell types along disease progression, profiling the RNA abundance of 52 samples from 13 patients enriched for one of four key cell types, spanning a wide CAPRA-S risk score range. Using a novel differential transcription Bayes method, TABI, we avoided a priori patient stratification, and mapped transcriptional alteration events to specific risk scores. The developmental and cell-type resolution yielded a landscape of concurrent transcriptional alterations from the tumour microenvironment, including key hallmarks. These transcriptional signatures permitted the identification of a “high survival” patient cluster in an independent prostate cancer dataset. Most importantly, together with our integrated transcriptional analysis, differential tissue composition analysis provided evidence for a key role for monocytes and macrophages in prostate cancer progression and disease recurrence.

  Study EGAS00001003579

• Analysis of copy number variation landscape of glioma by shallow coverage whole genome sequencing

  We reported shallow coverage whole genome sequencing (WGS) is an economic method for identification of whole genome somatic copy number variation (SCNV). Combining with a Taqman low density array (TLDA) designed for molecular subtyping of glioma, it enabled classification of glioma into biological entities with different cellular origin and genomic alterations. Further, we also showed shallow-coverage WGS enabled systematic identification of clonal and subclonal SCNV in glioma genomes and the burden and pattern of SCNV can serve as an objective marker of tumor progression and predict risk and relapse.

  Study EGAS00001003690

• Mesothelioma_Whole_Genomes

  Genomic architecture of mesothelioma parent study is project 925. This project is set up in parallel to project 925 in order to Whole genome sequence ten of the 59 tumours in that project.

  Study EGAS00001000830

• Whole genome shotgun sequencing and somatic mutations data in Hepatocellular carcinoma

  Hepatocellular carcinoma (HCC) is the most common malignancy of the liver. Genomic analysis is conducted to identify genetic alterations in driver genes which are all druggable targets for cancer therapy.

  Study EGAS00001002578

• Whole genome and whole transcriptome sequencing of patients diagnosed with angiosarcoma.

  Angiosarcomas are rare, clinically-aggressive tumors with a predilection for the elderly and immunosuppressed, which has incited suspicion of an oncogenic virus. We studied the metagenomic landscape of angiosarcomas and identified reads mapping to human herpesvirus-7 (HHV-7). Overall, HHV-7 was present in two-thirds of angiosarcomas, particularly in cases with low tumor mutation burden and lacking signatures of ultraviolet-induced DNA damage. Transcriptomic profiling revealed the enrichment of tumor inflammation signatures in HHV7-positive angiosarcomas. In conclusion, we identified a distinct “inflammatory” subtype of angiosarcoma associated with HHV-7.

  Study EGAS00001003895

• Pan-neuroblastoma analysis reveals age- and signature-associated driver alterations

  Neuroblastoma is a pediatric malignancy with heterogeneous clinical outcomes depending on age and other factors. To better understand neuroblastoma pathogenesis, here we analyze whole-genome, whole-exome and/or transcriptome sequencing data from 702 neuroblastoma samples, half of which are new data. Over 95% of samples harbor at least one recurrent driver alteration and most aberrations, including MYCN, ATRX, and TERT alterations, differ in frequency by age. MYCN alterations occur at median 2.3 years of age, TERT at 3.8 years, and ATRX at 5.6 years, suggesting age-specific susceptibility to genetic alterations. Mutational signature analysis shows that reactive oxygen-species (ROS)-induced mutations are the most common cause of single nucleotide variant (SNV) drivers in neuroblastoma, including most ALK and Ras pathway SNVs. ROS-induced mutagenesis is both an early event, as it causes truncal variants, and continuous as it also induces relapse-specific mutations. ROS-induced mutations are more abundant in neuroblastomas with MYCN amplification, 17q gains, and increased expression of mitochondrial ribosome genes. We observe recurrent FGFR1 N546K or internal tandem duplication variants in 6 patients and ALK N-terminal structural alterations in 5 samples, identifying additional patients amenable to precision therapy.

  Study EGAS00001003931