16599 results for "sec+and+unspecified+malignant+neoplasm"

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• Neuroblastoma relapse trio series from the AMC

  The majority of neuroblastoma patients have tumors that initially respond to chemotherapy, but a large proportion of patients will experience therapy-resistant relapses. The molecular basis of this aggressive phenotype is unknown. Whole genome sequencing of 23 paired diagnostic and relapsed neuroblastomas showed clonal evolution from the diagnostic tumor with a median of 29 somatic mutations unique to the relapse sample. Eighteen of the 23 relapse tumors (78%) showed RAS-MAPK pathway mutations. Seven events were detected only in the relapse tumor while the others showed clonal enrichment. In neuroblastoma cell lines we also detected a high frequency of activating mutations in the RAS-MAPK pathway (11/18, 61%) and these lesions predicted for sensitivity to MEK inhibition in vitro and in vivo. Our findings provide a rationale for genetic characterization of relapse neuroblastoma and show that RAS-MAPK pathway mutations may function as a biomarker for new therapeutic approaches to refractory disease.

  Study EGAS00001001183

• Whole exome sequencing of long-term, never relapse exceptional responders of trastuzumab-treated HER2+ metastatic breast cancer

  Trastuzumab has significantly improved the overall survival of patients with HER2+ metastatic breast cancer (MBC). However, outcomes can vary, with patients progressing within 1-year of treatment or exceptional cases of complete response to trastuzumab for ≥ 10 years. Identification of the underlying genomic aberrations of “exceptional responders (ExRs)” compared to “rapid non-responders (NR)” increases our understanding of the mechanisms involved in MBC progression and identification of biomarkers of trastuzumab response and resistance. Whole exome sequencing was performed on six ExRs compared to five NR. The overall fraction of genome copy number alteration (CNA) burden was higher in NR patients (P=0.07), while more significantly pronounced in copy number gains (P=0.03) in NR compared to ExRs. Delineation of the distribution of CNA burden across the genome identified a greater degree of CNA burden in NR within chr8 (P=0.02) and in chr17 (P=0.06) and conferred a statistically significant benefit in overall survival.

  Study EGAS00001004486

• MGMT genomic rearrangements contribute to chemotherapy resistance in gliomas

  Temozolomide (TMZ) is an oral alkylating agent used for the treatment of glioblastoma and is now becoming a chemotherapeutic option in patients diagnosed with high-risk low-grade gliomas1. The O-6-methylguanine-DNA methyltransferase (MGMT) is responsible for the direct repair of the main TMZ-induced toxic DNA adduct, the O6-Methylguanine lesion. MGMT promoter hypermethylation is currently the only known biomarker for TMZ response in glioblastoma patients2. Here we show that a subset of recurrent gliomas carry MGMT genomic rearrangements that lead to MGMT overexpression, independently from changes in its promoter methylation. By leveraging the CRISPR/Cas9 technology we generated some of these MGMT rearrangements in glioma cells and demonstrated that they lead to TMZ resistance both in vitro and in vivo. Lastly we showed that such fusions can be detected in tumor-derived exosomes and could potentially represent an early detection marker of tumor recurrence in a subset of patients treated with TMZ.

  Study EGAS00001004544

• UK renal cancer samples genotyped on Illumina OmniExpress BeadChip

  Renal cell carcinoma (RCC) cases comprised adult patients with histologically proven RCC were collected through two sources within the UK. First, 856 cases from SORCE, a MRC collection of surgically treated RCC cases ascertained through UK clinical oncology centres. Second, 189 RCC cases collected through the ICR and Royal Marsden NHS Hospitals Trust. Cases included 590 clear cell carcinomas (CCCs), 42 papillary carcinomas (PCs), 33 chromophobe carcinomas (CCs) and 19 mixed or other histological subtypes. DNA was extracted from EDTA-venous blood samples using the conventional methods and quantified using PicoGreen (Invitrogen). Cases were genotyped using the Human OmniExpress-12 BeadChip according to the manufacturer's recommendations (Illumina Inc, San Diego, CA, USA). After strict QC, 944 cases were retained. Data provided in plink format. Controls used were data from the Wellcome Trust Case Control Consortium 2 (WTCCC2) 1958 birth cohort and the UK Blood Service Control Group (available as EGAS00000000028).

  Study EGAS00001002336

• HSC_colony_many_years_post_allogeneic_bone_marrow_transplant_TGS

  This study looks at human donors and recipients of allogeneic blood & marrow marrow transplantation. Each transplant "pair" (donor & recipient) underwent the transplant procedure 10 -30 years prior to sampling - the majority for an underlying diagnosis of leukemia. We will perform whole-genome sequencing on tens to hundreds of single HSPC (haematopoietic stem and progenitor cell)-derived colonies per individual. We will infer the phylogeny of these cells (those from both donor & recipient within a pair) by analysing the somatically acquired mutations within each cell. The structure of the phylogeny will allow estimates of hitherto unknown parameters such as the number of HSCs that engraft long-term, the dynamics of the engraftment process on the HSC level, and the additional mutation burden acquired through the arduous transplant procedure. This TGS part of the study is used for assessing the contribution of clones to mature blood subsets, and better timing mutations relative to transplantation.

  Study EGAS00001005298

• Rare occurrence of Aristolochic Acid Mutational Signatures in Oro-Gastrointestinal Tract Cancers

  Aristolochic Acids (AAs) are a family of carcinogenic phytochemical compounds commonly found in plants of Aristolochia and Asarum genus. Comprehensive genomic profiling of genitourinary and hepatobiliary cancers has highlighted the widespread prevalence of Aristolochic Acid (AA) signatures in cancer patients across parts of Asia, particularly in Taiwan. The aim of our study was to determine in Oro-Gastrointestinal Tract (OGITC) cancers, the prevalence, role and significance that AA plays as a driver of tumorigenesis as AA containing products are commonly administered orally. This would suggest a possible etiological relationship between cancers of OGITC. However, in this study the rarity of AA mutational signatures in OGITC suggests that AA is unlikely to drive carcinogenesis in OGITC through direct exposure. Our study is valuable to show that AA exposure is not an equal driver of tumorigenesis in different organs and represents an important piece of information in the field.

  Study EGAS00001005909

• Somatic_mutation_profiling_of_intestinal_crypts_from_IBD_Full_STDY

  Following on from our pilot study we will investigate further the role that somatic mutations in intestinal stem cells play in IBD. We will use laser capture microdissection to ascertain epithelial cells from an individual crypts/vilus. We will extract DNA from these and use a new low-input material library prep methods to make accurate libraries for sequencing. We will perform 15X whole-genome sequencing of crypts biopsied from patients. Biopsies have been taken from inflammed and noninflammed patches to compare mutation rates and mutational signatures. We will also test if crypts from inflammed patches of a single patient are clonal (either within a given inflammed patch or across inflammed patches). We will quantify the rate of cancer driver mutations in inflammed and non-inflammed crypts. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/

  Study EGAS00001003249

• HSC_colony_many_years_post_allogeneic_bone_marrow_transplant___Bait_set_2

  This study looks at human donors and recipients of allogeneic blood & marrow marrow transplantation. Each transplant "pair" (donor & recipient) underwent the transplant procedure 10 -30 years prior to sampling - the majority for an underlying diagnosis of leukemia. We will perform whole-genome sequencing on tens to hundreds of single HSPC (haematopoietic stem and progenitor cell)-derived colonies per individual. We will infer the phylogeny of these cells (those from both donor & recipient within a pair) by analysing the somatically acquired mutations within each cell. The structure of the phylogeny will allow estimates of hitherto unknown parameters such as the number of HSCs that engraft long-term, the dynamics of the engraftment process on the HSC level, and the additional mutation burden acquired through the arduous transplant procedure. This TGS part of the study is used for assessing the contribution of clones to mature blood subsets, and better timing mutations relative to transplantation.

  Study EGAS00001005534

• Oncogenic cooperation in a human de novo T-ALL model

  We previously modelled T-cell acute lymphoblastic leukemia (T-ALL) by over-expressing four oncogenes (activated NOTCH1, LMO2, TAL1, and BMI1) in healthy human umbilical cord blood cells through lentiviral transduction (Kusakabe et al, Nat Commun 10, 2913 (2019). https://doi.org/10.1038/s41467-019-10510-8). We have now tested individual effects of the four oncogenes by transducing human cells with all possible combinations of one, two, three, and four oncogenes. We also tested the effects of additional known T-ALL oncogenes including HOXA9, LYL1, MEF2C, NXK2.1, TLX1, and TLX3. In addition to culture in vitro on OP9-DL1 feeders, we also injected transduced cells into immunodeficient NSG mice. We observed differing abilities of the various oncogene combinations to support growth in vitro and frank leukemia in vivo. This study includes RNA-seq data from samples of transduced cells cultured in vitro as well as cells harvested from clinically moribund mice after development of leukemia in vivo.

  Study EGAS00001006055

• Dissecting features of epigenetic variants underlying cardiometabolic risk using full-resolution epigenome profiling in regulatory elements

  Sparse profiling of CpG methylation in blood by microarrays have identified epigenetic links to common diseases. We apply methylC-capture sequencing (MCC-Seq) in a clinical population of ~200 adipose tissue and matched blood samples (Ntotal ~400), providing high-resolution methylation profiling (>1.3M CpGs) at regulatory elements. We link methylation to cardiometabolic risk through associations to circulating plasma lipid levels and identify lipid-associated CpGs with unique localization patterns in regulatory elements. We show distinct features of tissue-specific versus tissue-independent lipid-linked regulatory regions by contrasting with parallel assessments in ~800 independent adipose tissue and blood samples from the general population. We follow-up on adipose-specific regulatory regions under (1) genetic and (2) epigenetic (environmental) regulation via integrational studies. Overall, the comprehensive sequencing of regulatory element methylomes reveals a rich landscape of functional variants linked genetically as well as epigenetically to plasma lipid traits.

  Study EGAS00001003415