7252 results for "canc*"

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• Breast Cancer - Subtype defined by an amplification of the HER2 gene

  Clinically positive HER2 (cHER2+) breast cancers (BC) are defined by the amplification and overexpression of the human epidermal growth factor receptor (HER2/ERBB2) gene on chromosome region 17q12 and represent 15% of all BCs. Although anti-HER2 targeted therapies have improved BC’s natural history, the magnitude of their benefit varies widely between patients and deciphering the genomic heterogeneity of cHER2+ BC may provide a basis to better understand patients’ outcome. As part of the ICGC Breast Cancer Working Group effort, we combined whole genome sequencing and transcriptomic analyses of 64 cHER2+ primary invasive carcinomas.

  Study EGAS00001001431

• Genetic ancestry contributes to somatic mutations in lung cancers from admixed Latin American populations

  Inherited lung cancer risk, particularly in non-smokers, is poorly understood. Genomic and ancestry analysis of 1,153 lung cancers from Latin America revealed striking associations between Native American ancestry and their somatic landscape, including tumor mutational burden (TMB), and specific driver mutations in EGFR, KRAS, and STK11. A local Native American ancestry risk score predicted EGFR and KRAS mutation frequency more strongly than global ancestry, suggesting that germline genetics (rather than environmental exposure) underlie these disparities.

  Study EGAS00001004752

• Whole-exome sequencing of human pancreatic cancers and characterization of genomic instability caused by MLH1 haploinsufficiency and complete deficiency

  Whole-exome sequencing (Exome-Seq) has been successfully applied in several recent studies. We here performed Exome-Seq of 15 pancreatic tumor-normal pairs. We captured 162,073 exons of 16,954 genes and sequenced the targeted regions to a mean coverage of 56 folds. This study identified a total of 1,517 somatic mutations and validated 934 of them by transcriptome sequencing. We detected recurrent mutations in 56 genes. Among them, 41 have not been described. The mutation rates varied widely among tumors. The diversity of mutation rates was significantly correlated with the distinct MLH1 copy-number status. Exome-Seq revealed intensive genomic instability in a tumor with MLH1 homozygous deletion, indicated by a dramatically elevated mutation rate of somatic substitutions, small insertions/deletions (indels), as well as indels presented at microsatellites. Notably, we detected MLH1 allelic loss in 4 tumors. MLH1 expression was decreased by nearly half in these cases. While they were negative in the conventional microsatellite instability assay, they showed a 10.5-fold increase in the mutation rate of somatic indels, e.g. truncating indels in TP53 and TGFBR2, indicating MLH1 haploinsufficiency in correction of DNA indel errors. We further analyzed the exomes of 15 renal cell carcinomas (RCCs) and confirmed MLH1 haploinsufficiency. We observed a significant increase in the mutation rate of somatic indels in affected cases and identified recurrent truncating indels in several cancer genes such as VHL, PBRM1 and JARID1C. Together, our data suggest that MLH1 hemizygous deletion, through increasing the mutation rate of somatic indels, could drive the development and progression of sporadic cancers.

  Study EGAS00001000149

• Glioblastoma_CRISPR_Screen

  This is an in vitro genome-wide CRISPR/cas9 screen in human glioblastoma stem cells, screening for genes essential for survival of these cells. These cells express cas9 and have been transfected with a guide RNA library causing gene knockouts. We will analyse the sequencing data for depletion of guide RNAs.

  Study EGAS00001001519

• A comprehensive assessment of somatic mutation detection in cancer using whole genome sequencing

  As whole genome sequencing for cancer genome analysis becomes a clinical tool, a full understanding of the variables affecting sequencing analysis output is required. Using tumor-normal sample pairs from two different types of cancer, chronic lymphocytic leukemia and medulloblastoma, we conducted a benchmarking exercise within the context of the International Cancer Genome Consortium. We compare sequencing methods, analysis pipelines, and even validation methods. Here we show that using PCR-free methods and increasing sequencing depth to ~100x showed benefits, as long as the tumor:control coverage ratio remains balanced. We observe widely varying mutation call rates and low concordance among analysis pipelines, reflecting the artifact-prone nature of the raw data and lack of standards for dealing with the artifacts. However, armed with the benchmark mutation set we have created, we show that many issues are in fact easy to remedy and have an immediate positive impact on mutation detection accuracy.

  Study EGAS00001001539

• Whole genome sequencing of primary and metastatic Melanoma cases in an Australian cohort.

  Melanoma is the fourth most common cancer in Australia and the leading cause of cancer death in young adults. The Australian Melanoma Genome Project (AMGP) is analysing whole genomes from melanomas. We include the results of whole genome sequencing (WGS) for a number of datasets that include cutaneous, acral and mucosal melanoma subtypes.

  Study EGAS00001001552

• PSCP_mutation_analysis_in_hESCs

  Many studies over the past 10 years, culminating in the recent report of the International Stem Cell Initiative (ISCI, 2011) have shown that hPSC acquire genetic and epigenetic changes during their time in culture. Many of the genetic changes are non-random and recurrent, probably because they provide a selective growth advantage to the undifferentiated cells. Some are shared by embryonal carcinoma cells, the malignant counterparts of ES cells. The origins of these growth advantages are poorly understood, but may come from altered cell cycle dynamics, resistance to apoptosis or altered patterns of differentiation. Less is known about the nature and consequences of epigenetic changes, but it is likely that these similarly affect hPSC behaviour; e.g., enhanced expression of DLK1, an imprinted gene, is associated with altered hPSC growth (Enver et al 2005). Inevitably, these genetic and epigenetic changes will impact on our ability to use hPSC for regenerative medicine, either because malignant transformation of the undifferentiated cells or their differentiated derivatives to be used for transplantation compromises safety, or because they impede the function of those differentiated derivatives, or because they affect the efficiency with which the undifferentiated cells can be expanded and differentiated into desired cell types. Focusing initially upon the existing clinical grade hESC lines, later moving to iPSC, we will Consolidate and extend knowledge of the rate, type and functional impact of the genetic variations that occur during hPSC culture. We will use whole genome and exome sequencing as well as SNP arrays, together with clonal analysis and other cytogenetics techniques. Common changes will be compared with those found in the normal human population, at low frequency in the original cell population or observed during iPSC generation in the HIPSCI project currently based at the WTSI. These studies will provide a better understanding of the range of genetic changes that occur in hPSC beyond the CNVs already identified. In conjunction with cancer genome resources and expertise at WTSI, bioinformatic analyses of these hPSC data will allow us to assess potential impact on hPSC behaviour pertinent to applications in regenerative medicine, notably the likelihood that specific changes arising in undifferentiated PSC cultures may be associated with potential malignant transformation of differentiated progeny. This data is part of a pre-publication release. For information on the proper use of pre-publication data shred by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/

  Study EGAS00001001561

• The_genetic_evolution_of_precursor_lesions_in_pancreatic_cancer

  Mapping genetic evolution of pancreatic cancer precursor lesions such as IPMNs and PanINs.

  Study EGAS00001001573

• Rucaparib in patients presenting a metastatic breast cancer with Homologous Recombination Deficiency, without germline BRCA1/2 mutation, pronostic value of high LOH genomic score and predictive value of HRDetect (microarray)

  Breast cancer may present genomic alterations leading to homologous recombination deficiency. PARP inhibitors have proved their efficacy in patients with HER2-negative metastatic breast cancer (mBC) harboring germline (g) BRCA1/2 mutations. We conducted the phase 2 RUBY trial to assess the efficacy of rucaparib in HER2-negative mBC with high genomic loss of heterozygosity (LOH) score or somatic, without gBRCA1/2 mutation. 220 of 711 patients with mBC screened for LOH presented high LOH score which was associated with a higher likelihood of death (HR = 1.39, 95% CI: 1.11-1.75, p = 0.005). The primary objective was not reached with a clinical benefit rate (objective response or SD>16 weeks) of 13.5%. Two LOH-high patients, without somatic BRCA1/2 mutation, presented a complete and durable response (14 and 32 months). HRDetect tended to be associated with response to rucaparib, whithout reaching statistical significance (median HRDetect responders versus non responders: 0.465 versus, 0.040, p = 0.2135). Our data suggests that a small subset of patients with high LOH score could derive benefit from PARP inhibitors.

  Study EGAS00001004755

• Super enhancers define regulatory subtypes and cell identity in neuroblastoma

  Half of the children diagnosed with neuroblastoma have high-risk disease, disproportionately contributing to overall childhood cancer-related deaths. In addition to recurrent gene mutations, there is increasing evidence supporting the role of epigenetic deregulation in disease pathogenesis. Yet, comprehensive cis-regulatory network descriptions from neuroblastoma tissues are lacking. Here, using genome-wide H3K27ac profiles across 60 neuroblastomas, covering the different clinical and molecular subtypes, we identified four major super enhancer-driven epigenetic subtypes and their underlying master regulatory networks. Three of these subtypes recapitulated known clinical groups, namely MYCN amplified, MYCN non-amplified high-risk and MYCN non-amplified low-risk neuroblastomas. The fourth subtype, exhibiting mesenchymal characteristics, shared features with multipotent Schwann cell precursors, was induced by RAS activation and enriched in relapsed disease. Notably, CCND1, a disease essential gene, was regulated by both mesenchymal and adrenergic regulatory networks converging on distinct super-enhancer modules. Together, this reveals subtype-specific super-enhancer regulation in neuroblastoma.

  Study EGAS00001004551