3796 results for "*oma"

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• Immuno-genomic landscape of osteosarcoma

  Osteosarcoma is an orphan disease affecting children and young adults that has seen little to no progress in survival outcomes for >30 years. Despite having heavily rearranged genomes, to date, clinical trials with immunotherapy have shown no benefit for patients with osteosarcoma. In this study, we conducted the first multi-platform immune profiling (whole genome, transcriptome, T-cell receptor sequencing, immunohistochemistry and reverse phase protein array) on every available pediatric and adult osteosarcoma patients from our institution (N = 48) with the goal of describing immune features that may contribute to immunotherapy resistance.

  Study EGAS00001004197

• Pancreatic tropism of metastatic renal cell carcinoma

  Renal cell carcinoma (RCC) is characterized by a particularly broad metastatic swath, and enigmatically, when the pancreas is a destination, the disease is associated with improved survival. Intrigued by this observation, we sought to characterize the clinical behavior, therapeutic implications, and underlying biology. While pancreatic metastases (PM) are infrequent, we identified 31 patients across two institutional cohorts and show that improved survival is independent of established prognostic variables, that these tumors are exquisitely sensitive to anti-angiogenic agents and resistant to immune checkpoint inhibitors (ICI), and that they are characterized by a distinctive biology. Primary tumors of patients with PM exhibited frequent PBRM1 mutations, 3p loss, and 5q amplification, along with a lower frequency of aggressive features such as BAP1 mutations and loss of 9p, 14q, and 4q. Gene expression analyses revealed constrained evolution with remarkable uniformity, reduced T-effector gene signatures and increased angiogenesis. Similar findings were observed histopathologically. Thus, RCC metastatic to the pancreas is characterized by indolent biology, heightened angiogenesis, and an uninflamed stroma, likely underlying its good prognosis, sensitivity to anti-angiogenic therapies, and refractoriness to ICI. These data suggest that metastatic organotropism may be an indicator of a particular biology with prognostic and treatment implications for patients.

  Study EGAS00001004208

• Analysis of exonic somatic variants in light-chain amyloidosis (ALA) and ALA concomitant with multiple myeloma

  We aim to provide the very first insight into ALA+MM molecular profiles and compare the results with ALA and with MM. Our detailed study of ALA and ALA+MM represents an important step towards improved understanding of their genetic and transcriptomic background, which is a prerequisite for development of optimal treatment strategies in the future.

  Study EGAS00001004214

• Exome sequencing of familial high-grade serous ovarian carcinoma reveals heterogeneity for rare candidate susceptibility genes

  High-grade serous ovarian carcinoma (HGSOC) has a significant hereditary component, approximately half of which cannot be explained by known genes. To discover genes, we analyse germline exome sequencing data from 516 BRCA1/2-negative women with HGSOC, focusing on genes enriched with rare, protein-coding loss-of-function (LoF) variants. Overall, there is a significant enrichment of rare protein-coding LoF variants in the cases (p < 0.0001, chi-squared test). Only thirty-four (6.6%) have a pathogenic variant in a known or proposed predisposition gene. Few genes have LoF mutations in more than four individuals and the majority are detected in one individual only. Forty-three highly-ranked genes are identified with three or more LoF variants that are enriched by three-fold or more compared to GnomAD. These genes represent diverse functional pathways with relatively few involved in DNA repair, suggesting that much of the remaining heritability is explained by previously under-explored genes and pathways.

  Study EGAS00001004235

• Pediatric Low-Grade Glioma RNA and Targeted Sequencing

  Pediatric low-grade gliomas (pLGG) are frequently driven by genetic alterations in the RAS/MAPK pathway yet show unexplained variability in their clinical outcome. To address this, we characterized a cohort of >1,000 clinically annotated pLGG. 84% of cases harbored a driver alteration, while those without an identified alteration also often exhibited up-regulation of the RAS/MAPK pathway. pLGG could be broadly classified based on their alteration type. Rearrangement-driven tumors were diagnosed at a younger age, enriched for WHO grade I histology, infrequently progressed, and rarely resulted in death as compared to SNV-driven tumors. Further sub-classification of clinical-molecular correlates stratified pLGG into risk categories. These data highlight the biological and clinical differences between pLGG subtypes and opens avenues for future treatment refinement.

  Study EGAS00001004242

• Short and long-read genome sequencing methodologies for somatic variant detection; genomic analysis of a patient with diffuse large B-cell lymphoma

  Recent advances in throughput and accuracy mean that the Oxford Nanopore Technologies (ONT) PromethION platform is a now a viable solution for WGS. New bioinformatic methods have been developed to take advantage of this long read data, however much of the validation of these tools has focussed on calling germline variants (both SNVs and structural variants). Somatic variants are outnumbered many-fold by germline variants and their detection is further complicated due to their frequency varying depending on tumour purity/subclonality. Here, we evaluate the extent to which Nanopore WGS enables genome-wide detection and analysis of somatic variation. We do this through sequencing tumour and germline genomes for a patient with diffuse B-cell lymphoma. We examine the capability of currently available tools for calling somatic variants in ONT data by comparing the data with results from 150bp short-read sequencing of the same samples. We then conduct a detailed analysis of the performance of multiple long-read mappers and structural variant callers for calling large, somatic structural variants (SVs) in ONT data. Our protocol achieved yields of up to 96 mapped Gb per PromethION flow cell with average read lengths of ~5kb. Calling germline SNVs from these data achieved good specificity and sensitivity. However, results of somatic SNV calling highlight the need for the development of specialized joint calling algorithms. Our analysis of structural variants shows that the comparative performance of different tools varies significantly between SV types, and suggest long reads are especially advantageous for calling large somatic deletions and duplications. Finally, we highlight the utility of long reads for phasing clinically relevant variants by using the ONT data to confirm that a somatic 1.6Mb deletion and a p.(Arg249Met) mutation involving TP53 are oriented in trans.

  Study EGAS00001004266

• Mutation signatures in melanocytic nevi reveal characteristics of defective DNA repair

  Nevi are common benign melanocytic neoplasms that can be found on any skin location and share many of the genomic hallmarks of melanoma. In our recent report involving whole-exome sequencing of acquired nevi (Stark et al., 2018), ultra-violet radiation (UVR) related somatic mutation signatures (“signature 7”) (Alexandrov et al., 2013) were frequently observed in all lesions that were located on sun-exposed sites. In the study presented herein, we sought to investigate whether an independent Spanish cohort (Valencia, Spain) of minimally sun exposed nevi had genomic features consistent with our previous findings.

  Study EGAS00001004274

• Multiplexed quantification of four neuroblastoma DNA targets in a single droplet digital PCR reaction

  Evaluation of quadruplex ddPCR-based copy number assessment in blood plasma samples paired with genomic DNA from the corresponding primary neuroblastoma from three patients and comparison with copy numbers determined by duplex and triplex ddPCR and re-analyzed from whole-exome sequencing (WES) data.

  Study EGAS00001004275

• Roma Sequencing Study

  Present day Roma genome were shaped by the extensive inbreeding and admixture during their Diaspora. Here, we shed light on the Roma demographic history by analyzing the whole genome sequence of 46 Roma individuals pertaining to four migrant groups in six European countries. The strong reduction in effective population size (~44%), that occurred around 2kya, was not masked by the subsequent high admixture in Middle Eastern and European countries.

  Study EGAS00001004287

• Interplay of somatic alterations and immune infiltration modulates response to PD-1 blockade in advanced clear cell RCC -- CA209-009

  Immune checkpoint inhibitors targeting the PD-1 pathway have transformed the management of many advanced malignancies, including clear cell renal cell carcinoma (ccRCC), but the drivers and resistors of PD-1 response remain incompletely elucidated. Here, we analyzed 592 tumors collected from advanced ccRCC patients enrolled in prospective clinical trials of treatment with PD-1 blockade (or mTOR inhibition as control arm) by whole-exome and RNA-sequencing, integrated with immunofluorescence analysis, to define the somatic alteration landscape of late-stage ccRCC and to uncover the immunogenomic determinants of therapeutic response. While conventional genomic markers (tumor mutation burden, neoantigen load) and degree of CD8+ T cell infiltration were not associated with clinical response, we discovered numerous chromosomal alterations in advanced ccRCC associated with response or resistance to PD-1 blockade. These advanced tumors were highly CD8+ T cell infiltrated, with only 22% and 5% with an immune desert and immune excluded phenotype, respectively. Our analysis revealed that CD8+ infiltrated tumors are depleted of favorable PBRM1 mutations and are enriched for unfavorable chromosomal losses of 9p21.3 when compared to non-infiltrated tumors. These data demonstrate how the interplay of somatic alterations and immunophenotypes impacts therapeutic efficacy.

  Study EGAS00001004290