4748 results for "*oma"

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• High response rate to anti PD-1 therapy in desmoplastic melanoma

  Desmoplastic melanoma (DM) is a rare subtype of melanoma characterized by dense fibrous stroma, resistance to chemotherapy and a lack of actionable driver mutations, but is highly associated with ultraviolet light DNA damage. We analysed 60 patients with advanced DM treated with programmed cell death 1 (PD-1) or PD-1 ligand (PD-L1) blocking antibody therapy. Objective tumor responses were observed in 42 of the 60 patients (70%, 95% confidence interval 57-81%), including 19 patients (32% overall) with a complete response. Whole-exome sequencing revealed a high mutational load and frequent NF-1 mutations (14 out of 17 cases). Immunohistochemistry (IHC) analysis from 19 DM and 13 non-DM revealed a higher percentage of PD-L1 positive cells in the tumor parenchyma in DM (p = 0.04), highly associated with increased CD8 density and PD-L1 expression in the tumor invasive margin. Therefore, patients with advanced DM derive significant clinical benefit from PD-1/PD-L1 immune checkpoint blockade therapy despite being a cancer defined by its dense desmoplastic fibrous stroma. The benefit is likely derived from the high mutational burden and a frequent pre-existing adaptive immune response limited by PD-L1 expression.

  Study phs001469

• Intraductal transplantation models of human pancreatic ductal adenocarcinoma reveal progressive transition of molecular subtypes

  Pancreatic ductal adenocarcinoma (PDAC) is the most lethal common malignancy, with little improvement in patient outcomes over the past few decades. Recently, subtypes of pancreatic cancer with different prognoses have been elaborated. However, the inability to model these subtypes has precluded mechanistic investigation of their origins. Here, we present an orthotopic xenotransplantation model of human patient-derived PDAC organoids in which organoids are grafted via direct injection into the pancreatic duct of immunocompromised (NSG) mice. Tumors that arise from these intraductally grafted organoids (IGOs) enable the distinction of the two main PDAC subtypes: intraepithelial neoplasms from this model progress in an indolent or invasive manner representing the classical or basal-like subtypes of PDAC, respectively, depending on which organoid they originate from. RNA-sequencing was used to characterize the tumors that resulted from IGO xenografts, and to compare the fast- and slow-progressing IGO tumors. Tumors generated using a traditional orthotopic xenograft model, in which organoids are injected into the parenchyma of the pancreas (i.e. orthotopically grafted organoids, or OGOs), were also sequenced for comparison with the IGO tumors. To further characterize the model, laser-capture microdissection followed by RNA-sequencing was used to compare intraductal to invasive lesions resulting from IGOs. To better understand the connection between KRAS signaling and the fast-progressing phenotype, RNA-sequencing was used to compare cultured organoids in which oncogenic KRAS (GeneID: 3845) was hyperactivated to control organoids, and to compare laser-capture microdissected lesions derived from IGOs of KRAS-hyperactivated organoids to lesions derived from control organoids. To ascertain copy number, low-coverage, whole genome DNA-sequencing was performed on organoids cultured in vitro, and on laser-capture microdissected lesions derived from IGO tumors.

  Study phs002045

• Towards a Genomic Understanding of Myeloma

  This project was designed to describe genetic abnormalities in primary samples from patients with multiple myeloma by next generation sequencing. We generated sequence data from multiple myeloma (MM) patients analyzing DNA both from tumor cells (purified from bone marrow using CD138 selection as a marker of plasma cells) and from normal peripheral blood cells (either whole blood or Ficoll-purified mononuclear cells). Using massively parallel sequencing technology (Illumina GA-2 or HiSeq)), we performed whole-genome sequencing (WGS) and/or whole-exome sequencing (WES). The initial set currently deposited contains data from 38 MM patients (23 patients surveyed by WGS and 16 patients by WES, with one patient analyzed by both approaches). Genomes were sampled to high depth, obtaining an average of 33X coverage and 104X coverage for WGS and WES tumors, respectively. The normal samples had similar coverage. Our goal is to help researchers understand the complex genetic landscape of multiple myeloma and provide a resource for the generation of biological hypotheses.

  Study phs000348

• Genentech whole genome and transcriptome sequencing of four hepatocellular carcinoma patients

  Hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC). In this study we sequenced the whole genome (~80X) and transcriptome of tumor and non-tumor samples from four HCC patients and identified over two hundred HBV integration sites. We found significant clonal expansion of HBV-integrated hepatocytes specifically in the tumor samples. We observed a diverse collection of genomic perturbations near viral integration sites, including gene disruption, viral promoter-driven human transcription, viral-human transcript fusion and DNA copy number alteration. We also sequenced one patient at ultra-high coverage (~240X) to build the most comprehensive HBV-integration landscape yet attempted. Our data suggest that the viral integration significantly expands carcinogenic opportunities in HBV-infected individuals.

  Study phs000384

• Preclinical Modeling of Leiomyosarcoma Identifies Susceptibility to Transcriptional CDK Inhibitors through Antagonism of E2F-Driven Oncogenic Gene Expression

  Leiomyosarcoma (LMS) is a smooth muscle-derived mesenchymal cancer commonly found to have recurrent loss of tumor suppressor genes and a poorly defined oncogenic program. Empiric cytotoxic chemotherapy is the standard systemic treatment for LMS, and while more targeted and effective therapies are urgently needed, insights into therapeutic vulnerabilities in LMS have been limited by available preclinical models. We generated a panel of LMS patient-derived xenograft (PDX) models and evaluated fidelity to their tumors of origin using RNA sequencing and ultra-low passage whole-genome sequencing (ULP-WGS). Data available at dbGaP include RNA sequencing and ULP-WGS of primary tumors and early and late passages of PDX. 

  Study phs002587

• A Pilot Study of Rapid Autopsy and Procurement of Tissue in Thoracic Malignancy Cancer Patients to Investigate Tumor Heterogeneity

  Integrated proteo-genomics studies to characterize tumor heterogeneity of metastatic lung adenocarcinoma and thymic carcinoma are lacking. We carried out whole exome sequencing, RNA sequencing, copy number estimation and mass spectrometry-based proteomics of 40 tumors from five rapid/warm autopsy patients. We found highly variable mutational heterogeneity that was largely driven by APOBEC-mutagenesis with the expression of APOBEC3B (Gene ID: 9582) and APOBEC3A_B (Gene ID: 100913187) due to underlying APOBEC3 region germline variants as the likely mediating mechanism. APOBEC3A_B expression was associated with increased immune tumor microenvironment and CD274 (Gene ID: 29126) expression while smoking was associated with increased APOBEC-mutagenesis in TP53 (Gene ID: 7157) mutant tumors with high APOBEC3B expression. Heterogeneity at the level of the transcriptome and proteome occurred in association with copy number heterogeneity, not APOBEC-induced mutational heterogeneity. Arm and focal copy number alterations (CNAs) occurred as an evolutionarily late event in a subset of patients, with corresponding changes in the transcriptome and proteome, implicating CNAs as a driving force of heterogeneity in the evolution of metastatic disease.

  Study phs001432

• Integrative Genomic and Transcriptomic Analyses of Refractory Multiple Myeloma

  This study reports results from integrative sequencing analyses that combine capture transcriptome sequencing with a comparative analysis of exome capture between the malignant plasma cells and normal cells of patients with relapsed and refractory multiple myeloma (RRMM). This approach has enabled the detection of point mutations, insertions/deletions, gene fusions and rearrangements, amplifications/deletions, and outlier expressed genes among other classes of alterations that contribute to disease progression and drug resistance in the RRMM patients. 

  Study phs002498

• Gene Fusion Discovery through RNA Sequencing of Human Glioblastoma Stem Cell Lines

  We used massively parallel, paired-end sequencing of expressed transcripts (RNA-seq) to detect novel gene fusions in short-term cultures of glioma stem-like cells freshly isolated from nine patients carrying primary glioblastoma multiforme (GBM). The culture of primary GBM tumors under serum-free conditions selects cells that retain phenotypes and genotypes closely mirroring primary tumor profiles as compared to serum-cultured glioma cell lines that have largely lost their developmental identities.

  Study phs000505

• Childhood Cancer Data Initiative (CCDI): Clonal Evolution During Metastatic Spread in High-Risk Neuroblastoma

  The goal of this study is to deliver a detailed characterization of the patterns of disease dissemination at diagnosis, during progression and in response to therapy in high-risk neuroblastoma. Longitudinal and spatially distinct tumors were collected from patients. Clinical data includes diagnosis and treatment information. Biospecimen data includes whole genome sequencing (WGS) and whole transcriptome sequencing (WTS).

  Study phs003111

• Intercepting Progression from Pre-Invasive to Invasive Lung Adenocarcinoma

  An improved understanding of the biology of lung cancer is needed to intercept the disease at an early point in its progression. In this project we have used multidimensional methods to profile the tumor microenvironment (TME) and to determine the crosstalk between cancer cells and the TME in pre-invasive to invasive human lung non-solid adenocarcinomas. Comparative analysis of the cellular and molecular events associated with the distinct histological stages will lead to identification of the critical events triggering progression and thereby identify targets to intercept disease progression. The data being submitted represents the genomic profiles of patient samples with pre-invasive and invasive human lung adenocarcinomas.

  Study phs002818