4895 results for "*oma"

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• Patient-derived tumor organoids for personalized medicine in a rare case of hepatocellular carcinoma with neuroendocrine differentiation.

  We report the case of a 74-year-old man with a very rare subtype of hepatocellular carcinoma with neuroendocrine differentiation (HCC-NED). The patient presented with two independent tumors, a gastrointestinal stromal tumor in the stomach and a hepatocellular carcinoma in the liver. Both tumors were surgically removed in curative intent. Histopathological work-up of the liver tumor revealed poorly differentiated hepatocellular carcinoma (Edmondson-Steiner grade IV) with diffuse expression of neuroendocrine markers synaptophysin (SYP) and chromogranin (CHGA). Three months after resection, multifocal recurrence of the HCC with neuroendocrine differentiation (HCC-NED) was observed. In the meantime, tumor organoids have been generated from the resected HCC-NED and extensively characterized. Sensitivity to a number of drugs approved for the treatment of HCC or neuroendocrine carcinomas was tested in vitro. Based on their in vitro efficacy, etoposide and carboplatin were used as first line palliative combination treatment. Because genomic analysis revealed a NTRK1-mutation (kinase domain) and tumor organoids were sensitive to entrectinib, a pan-TRK inhibitor, the patient received entrectinib as second line therapy. After only two weeks, treatment had to be discontinued due to deterioration of the patient’s general condition. In conclusion, we demonstrate for the first time that preclinical drug testing using organoids is feasible in selected HCC cases.

  Study EGAS00001005887

• Neuroblastoma and adrenal gland single-cell study

  Neuroblastoma is a pediatric tumor of the developing sympathetic nervous system. However, the cellular origin of neuroblastoma remains to be defined. Here, we study single-cell transcriptomes of neuroblastomas and normal human developing adrenal glands at various stages of embryonic and fetal development. We define normal differentiation trajectories during adrenal medullary development and identify the cellular origin of neuroblastoma. Importantly, adrenergic and mesenchymal neuroblastomas with varying clinical phenotypes match different temporal states along normal differentiation trajectories, with the degree of differentiation corresponding to clinical prognosis.

  Study EGAS00001004388

• Single cell copy number and chromatin accessibility in primary multiple myeloma cells

  Multiple myeloma is characterized by inter- and intra-clonal heterogeneity. We have used single cell profiling of the genome (scCNV) and epigenome (csATAC) of clonal plasma cells to delineate the clonal heterogeneity in serially collected samples.

  Study EGAS00001005382

• Integrative Profiling of T790M Negative EGFR Mutated NSCLC Reveals Pervasive Lineage Transition and Therapeutic Opportunities

  We performed whole exome and transcriptome analysis of 59 first- and second-generation EGFR TKI resistant metastatic EGFR mutated patients to characterize and compare molecular alterations mediating resistance in T790M positive and negative disease. Transcriptomic analysis revealed ubiquitous loss of adenocarcinoma lineage gene expression in T790M negative tumors, orthogonally validated using multiplex immunohistochemistry. There was enrichment of genomic features such as TP53 alterations, 3q chromosomal amplifications, whole genome doubling and non-aging mutational signatures in T790M negative tumors. Almost half of resistant tumors were further classified as Immunehot, with clinical outcomes conditional on immune cell infiltration state and T790M status. Finally, using a Bayesian statistical approach, we explored how T790M negative and positive disease might be predicted using comprehensive genomic and transcriptomic profiles of treatment-naïve patients.

  Study EGAS00001005389

• Functional dissection of inherited non-coding variation influencing multiple myeloma risk

  The project aimed at identification of genotype dependent chromatin accessibility in MM patients.

  Study EGAS00001005394

• A mechanistic classification of clinical phenotypes in neuroblastoma

  Clinical courses of the pediatric tumor neuroblastoma range from fatal progression to spontaneous regression. To gain insights into the pathogenesis of these divergent subtypes, we performed massively parallel sequencing of 416 pretreatment neuroblastomas and assessed telomere maintenance mechanisms in 208/416 cases. We observed that telomere maintenance and mutations in RAS or p53 pathway genes strongly affected disease courses. Fatal outcome occurred only in the presence of telomere maintenance, whereas patients whose tumors lacked such mechanisms had excellent outcome. In patients with telomere maintenance-positive tumors, survival was dramatically inferior when additional RAS/p53 pathway mutations were present. By contrast, spontaneous regression occurred both in the presence and absence of RAS/p53 pathway mutations in patients with telomere maintenance-negative tumors. Together, our data provide a precise mechanistic classification of clinical neuroblastoma phenotypes based on telomere maintenance mechanisms and genetic alterations of the tumor.

  Study EGAS00001003244

• Pediatric Papillary Thyroid Carcinoma RNA-Seq

  Papillary thyroid carcinoma (PTC) is the most common malignancy amongst adolescent and young adult women. Clinical and genomic features of PTC in children differ from those in adults. Historically, a substantial proportion (~50%) of pediatric PTC (PPTC) lack any of the common driver mutations typical of adult PTC. Thus, molecular diagnostics developed for adults may not be valid in children. We applied novel bioinformatic pipelines to RNASeq analysis of pediatric thyroid tumors to identify known and novel fusion oncogenes as drivers of tumorigenesis and to define gene expression patterns among tumors. Analysis of 38 samples resulted in identification of 16 previously reported oncogenic fusions and three novel candidate fusions. In conducting these analyses, we reduced the proportion of cancers with unknown drivers from approximately 50% to 6%. Gene expression analysis identified three distinct categories of tumors. These studies represent the first unbiased genomic approach to childhood PTC. Novel bioinformatic pipeline. GEC Identified 3 distinct classes. DICER1, PTEN segregated with benign tumors. >90% of PPTC carry identifiable ongognic driver variants, however, the landscape differs from that in adults and existing tools for tumor genotyping in adults may not be applicable to pediatric tumors. BACKGROUND: Papillary thyroid carcinoma demonstrates clinically distinct behaviour in pediatric patients when compared to adults, with increased regional and distal metastases, more frequent recurrence, yet overall highly favourable prognosis. Recent tumor genotyping has demonstrated that in pediatric tumors, ***-*** do not carry the most common genomic variants found in adult PTC, leaving a substantial proportion of driver-unknown or “dark matter” tumors. METHODS: We established a cohort of 52 pediatric PTC and performed quantitative-PCR genotyping followed in a subset by whole exome and whole transcriptome (RNASeq) sequencing using a novel, robust bioinformatic pipeline to identify oncogenic fusion transcripts. Gene expression analysis was used to derive distinct clusters. RESULTS: In 52 pediatric PTC, genotyping identified BRAFV600E(21%), NRASQ61R(2%), RET/PTC1 (21%), RET/PTC3 (17%) or PAX8-PPAR in 33 (63%) of tumors. Among the remaining 19 tumors, oncogenic variants were identified in /19 (%). The variants included SNVs in DICER1, ETV6-NTRK3, PTEN and 9 additional oncogenic fusions including two previously-undescribed fusion transcripts, *** and ***. CONCLUSIONS: The genomic landscape of PTC differs between children and adults. In children, there is a substantial fraction of tumors that are unexplained by variants typical of adult PTC. This discrepancy is explained largely by uncommon oncogenic fusions which can be identified by whole-transcriptome analysis.

  Study EGAS00001005182

• Overactivation of the IGF signalling pathway in osteosarcoma

  Tumour samples (low coverage WGS) from 35 patients with osteosarcoma were included. All samples were re-evaluated by an experienced bone pathologist who confirmed the diagnosis and a tumour content >50% per sample. All tumours represented conventional high-grade osteosarcomas.

  Study EGAS00001004767

• Characterizing the immune and genome landscapes for osteosarcoma

  Osteosarcoma have heavily rearranged genomes and moderate tumor mutation burden, which suggests that the patients may express neoantigens that could be targeted by immune cells. To characterize the immunogenomic landscape of this disease, we performed genome, transcriptome, immune and proteomic profiling of 48 patients comprised largely of relapsed and metastatic cases from both pediatric and adult patients.

  Study EGAS00001003247

• Single-cell analysis for metastatic gastric adenocarcinoma

  Intra-tumoral heterogeneity (ITH) is the fundamental property of cancer, however, the origins of ITH remain poorly understood. Here we performed single-cell RNA sequencing of peritoneal carcinomatosis (PC) from patients with advanced gastric adenocarcinoma (GAC), constructed a transcriptome map of 45,048 PC cells, profiled the transcriptome states of diverse tumor cell lineages and types, incisively explored ITH of PC tumor cells, and identified significant correlates with patient survival.

  Study EGAS00001004443