4748 results for "*oma"

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• Genomic Landscape of Human Skin at a Single-Cell Resolution

  Every cell in the human body has a unique set of somatic mutations, yet it remains difficult to comprehensively genotype an individual cell. Here, we developed solutions to overcome this obstacle in the context of normal human skin, thus offering the first glimpse into the genomic landscapes of melanocytes at single-cell resolution. We comprehensively genotyped 133 melanocytes from 19 sites across 6 donors. As expected, sun-shielded melanocytes had fewer mutations than sun-exposed melanocytes. However, within sun-exposed sites, melanocytes on chronically sun-exposed skin (e.g. the face) displayed a lower mutation burden than melanocytes on intermittently sun-exposed skin (e.g. the back). Melanocytes from donors with a history of skin cancer had higher mutation burdens than melanocytes from donors without skin cancer, implying that the mutation burden of normal skin can be harnessed to measure cumulative sun damage and skin cancer risk. Moreover, melanocytes from healthy skin commonly harbor pathogenic mutations, likely explaining the origins of the melanomas that arise in the absence of a pre-existing nevus. Phylogenetic analyses identified groups of related melanocytes, suggesting that melanocytes spread throughout skin as fields of clonally related cells, invisible to the naked eye. Overall, our study offers an unprecedented view into the genomic landscapes of individual melanocytes, revealing key insights into the causes and origins of melanoma.

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• Molecular Basis of Neuroendocrine Prostate Cancer (Trento/Cornell/Broad 2015)

  A subset of advanced prostate cancers can progress from an androgen receptor (AR)-driven state to AR independence, often associated with low or absent AR expression and extensive neuroendocrine differentiation. Once neuroendocrine prostate cancer (NEPC) develops, patients typically demonstrate an aggressive clinical course and poor overall survival. Early diagnosis is important but remains challenging as the clinical and pathologic features associate with AR independence and NEPC are poorly defined. We performed whole exome sequencing of 114 metastatic tumors from 81 patients (35 with morphologic features of NEPC). Serial or synchronous samples were included to characterize heterogeneity and the transition from adenocarcinoma to NEPC. Computational analysis of clonality and allele specific quantification were performed using CLONET. Quantitative mRNA assessment including AR signaling genes and DNA methylation were evaluated in the context of genomic changes.

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• A Whole Genome Association Scan for Myopia and Glaucoma Endophenotypes using Twin Studies

  Myopia and glaucoma are highly prevalent ophthalmic disorders worldwide and contribute significantly to ocular morbidity. There is substantial evidence that genetic factors play a significant role in the development of non-syndromic myopia and glaucoma. We propose to perform mapping studies for well-characterized twin populations in the United Kingdom and Australia in order to ultimately identify implicated genes for these disorders and related ocular parameters. This will provide a fundamental molecular understanding of how these disorders develop, and may lead to directed physiologic (i.e. pharmacologic, gene therapy) interventions. Our aim is to dissect the genetic basis of the eye disorders myopia and glaucoma. Instead of limited analyses of the trait/disease in a dichotomous manner, we are using continuous phenotypes of measures of refraction and intermediate phenotypes of glaucoma to analyze quantitative traits in unselected population samples of volunteer twins. Achievement of this goal requires cooperative efforts and large sample sizes. Thus, we have created an international collaboration of large complementary studies.

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• A New Pipeline to Predict and Confirm Tumor Neoantigens Predicts Better Response to Checkpoint Blockade

  Mutations that drive oncogenesis in cancer can generate neoantigens that may be recognized by the immune system. Identification of these neoantigens remains challenging due to the complexity of the major histocompatibility complex (MHC) antigen and T-cell receptor interaction. Here we describe the development of a systematic approach to efficiently identify and validate immunogenic neoantigens. Whole exome sequencing of tissue from a melanoma patient was used to identify nonsynonymous mutations, followed by MHC binding prediction and identification of tumor clonal architecture. The top 18 putative class I neoantigens were selected for immunogenicity testing via a novel in vitro pipeline in HLA-A201 healthy donor blood. Naive CD8 T cells from donors were stimulated with allogeneic dendritic cells pulsed with peptide pools and then with individual peptides. The presence of antigen-specific T cells was determined via functional assays. We identified one putative neoantigen that expanded T cells specific to the mutant form of the peptide and validated this pipeline in a subset of patients with bladder tumors treated with durvalumab (N = 5). Within this cohort, the top predicted neoantigens from all patients were immunogenic in vitro. Finally, we looked at overall survival in the whole durvalumab-treated bladder cohort (N = 37) by stratifying patients by tertile measure of tumor mutation burden (TMB) or neoantigen load. Patients with higher neoantigen and TMB load tended to show better overall survival.

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• National Cancer Institute Cancer Genome Characterization Initiative (CGCI)

  The Office of Cancer Genomics at the National Cancer Institute sponsored a series of studies as part of the Cancer Genome Characterization Initiative (CGCI) to assess novel emerging sequencing technologies in cancer. The CGCI program included comprehensive characterization of the genetic aberrations found in different pediatric and/or adult tumors. CGCI characterized a number of B-cell non-Hodgkin lymphomas (including diffuse large B-cell lymphoma (DLBCL) from patients with and without HIV+ infection, follicular lymphoma (FL), as well as adult and pediatric Burkitt lymphomas), and additional HIV-associated tumors (including DLBCL, lung, and cervical cancers). All data from these projects is available at the NCI Genomic Data Commons. Individual project descriptions are available by disease on the substudy pages (links are included at the top of this page). Brief summaries are as follows: Non-Hodgkin Lymphoma (NHL) - CGCI investigators probed genomic alterations more deeply than had previously been possible by using state-of-the-art RNA sequencing (mRNA-seq) and whole genome shotgun sequencing (WGS) coupled with leading edge bioinformatics, data management and analysis approaches. The project sequenced tumor DNA and/or RNA from 117 NHL tumor samples and 10 cell lines. This included the genomes or exomes of 1 Follicular Lymphoma (FL) and 13 diffuse large B-cell lymphoma (DLBCL) cases, all with matched constitutional DNA sequenced to comparable depths, RNA-sequencing (mRNA-seq) of 92 DLBCL, 12 FL and 8 B-cell NHL cases with other histologies and 10 DLBCL-derived cell lines. The DLBCL cases and cell-lines are from the two major subtypes of DLBCL: germinal center B-cell (GCB) and activated B-cell (ABC). HIV+ Tumor Molecular Characterization Project (HTMCP) - This project was a joint effort of the Office of Cancer Genomics (OCG) and the Office of HIV and AIDS Malignancy (OHAM). Its goals were to characterize HIV-associated cancers (obtained from HIV-infected patients) and compare them to the same types of cancers from patients without HIV infection. Investigators performed 30X genome sequencing of 100 cases of paired tumor and germline DNA, along with transcriptome sequencing in each of 3 types of HIV+ tumors (DLBCL, lung and cervical cancers). These platforms allow discovery of mutations both in coding and non-coding genomic regions, gene expression and genomic alterations (including translocations, insertions and deletions). Comparing tumors of cancer patients both with and without HIV-infection provides insight into the potential function of this virus in certain cancers. Burkitt Lymphoma Genome Sequencing Project (BLGSP) - This project was a collaborative effort between the National Cancer Institute and the Foundation for Burkitt Lymphoma Research to develop a databank of the many alterations found in Burkitt lymphoma (BL), an uncommon type of Non-Hodgkin lymphoma that occurs most often in children and young adults. The goal of the BLGSP was to explore potential genetic changes in patients with BL that could lead to better prevention, detection and treatment of the cancer. The project characterized the alterations of the tumors' genomes (with matched normal as control) and transcriptomes by sequencing the DNA and RNA of each case. Using the data generated, the ultimate goals of the project was to discover the molecular changes that are present in BL patients and then determine how those changes correlate with treatment regimen and outcome. CGCI data is accessible at the NCI's Genomic Data Commons (GDC) via the GDC's Data Portal and from each of the CGCI Publication Pages at the GDC (Please see the "Supplemental Links" section of any CGCI publication's "Publication Information and Associated Data Files page" at the GDC.). Available datasets include raw sequencing data, datasets generated by the original CGCI research teams (fully annotated clinical information and higher-level/analyzed molecular characterization data), as well as higher level data generated by the GDC. Please see the CGCI Use and Publication Guidelines for updated details on the sharing of any CGCI substudy data, including how to cite CGCI.To learn more about the CGCI studies, please visit the CGCI Program website.

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• Genomic and transcriptomic characterization of chordoma

  In this study, we performed paired tumor/normal whole exome and shallow long insert whole genome sequencing, as well as tumor RNAseq, from archival chordoma specimens collected from four patients at the Barrow Neurological Institute in Phoenix, AZ. The purpose of this analysis was to identify potential therapeutic targets. In three patients, we observed that although different DNA and RNA changes were present in each tumor, alterations fell on converging pathways. In the fourth patient, constitutional DNA demonstrated potentially pathogenic alterations that may have predisposed the patient to chordoma.

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• Multiregional Single-Cell Transcriptomic Analysis of Liver Cancer

  In this study, we performed single-cell transcriptomic profiling of human liver tissues collected from hepatocellular carcinoma and intrahepatic cholangiocarcinoma patients. A total of seven primary liver cancer patients enrolled in this study. Samples were collected from multiple regions, including tumor core, tumor border and adjacent non-tumor tissue. The 10x Genomics platform was used to generate single cell 5' libraries. The Illumina NovaSeq 6000 platform was employed for sequencing.

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• Germline Genetic Variants in Cancer-Susceptibility Genes in Patients with Osteosarcoma

  We conducted whole-exome sequencing of germline DNA from patients with osteosarcoma to estimate the frequency of pathogenic/likely pathogenic germline genetic variants in known cancer-susceptibility genes in a large population of osteosarcoma patients unselected for family history.

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• Tumor heterogeneity and acquired drug resistance in FGFR2 fusion-positive cholangiocarcinoma through rapid research autopsy

  Whole exome sequencing was performed on blood and tumor specimens (collected from biopsy or rapid research autopsy) from a patient with FGFR2 fusion positive cholangiocarcinoma.

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• Study of Tumor Recurrence Related to the Expression of the PAX3-FOXO1 Oncogenic Transcription Factor in Fusion-Positive Rhabdomyosarcoma

  Alveolar rhabdomyosarcoma (ARMS) is a highly aggressive pediatric soft tissue cancer characterized by a recurrent 2;13 chromosome translocation. This translocation generates a PAX3-FOXO1 (P3F) fusion gene, which encodes a chimeric transcription factor with oncogenic activity. Using a human myoblast system that models targeted therapy directed against P3F, we demonstrated that the expression of the fibroblast growth factor 8 (FGF8), a direct transcriptional target of P3F, is necessary and sufficient for PAX3-FOXO1-independent tumor recurrence in addition to be required for the tumorigenic activity of primary tumors expressing P3F. In addition, we showed that FGF8 is expressed in human rhabdomyosarcoma cell lines that express P3F. We also demonstrated that FGF8 contributes to their proliferation and transformation in vitro, and is sufficient to maintain their oncogenicity after the loss of P3F expression. We suggest that targeting the expression of the PAX3-FOXO1 transcription factor can generate resistance and recommend that additional anticipated therapeutic approaches, such as targeting FGF8 pathway, may avoid this resistance mechanism.

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