Search Results - EGA European Genome-Phenome Archive

The mutational landscape of skin tumours in CYLD cutaneous syndrome determined

Patients with germline mutations in CYLD can develop hundreds of benign skin tumours called cylindromas. The development of multiple tumours within a single patient at sun-protected and sun-exposed sites, varying tumour histological patterns and grades of malignancy allow for the testing of several genetic hypothesis in relation to cutaneous carcinogenesis. By adopting the unprecedented approach of whole genome sequencing of multiple benign skin tumours within individuals in multigenerational families, we set out to study the impact of mutational diversity on models such as multistep carcinogenesis as well as non-sequential carcinogenesis. Using non-negative matrix factorisation (NMF) to discover mutational signatures, we found distinct mutational signatures in identical benign tumours (N=2 patients; n=11 tumours) at sun exposed and sun protected skin tumours within a mother and her daughter. We found recurrent mutations in epigenetic modifying genes in CCS tumours which are known to have an oncogenic dependency on Wnt signalling. We also demonstrate that cutaneous tumours that metastasize to the lung carry a a UV signature, supporting the origin from the skin. Distinct malignant tumours, such as BCC and malignant spiradenocarcinoma carried unique driver mutations. These findings add new dimensions to the existing paradigms of UV-induced skin cancer and highlight the utility of studying rare disease to gain novel insights into genetic mechanisms of tumour formation.

Dataset EGAD00001004573

Genomic and transcriptomic analysis of thymic epithelial tumors

Thymic epithelial tumors (TETs), comprising various histologic types of thymomas and thymic carcinomas, originate from thymic epithelial cells. Each histologic type is typically associated with a distinct immune cell composition and clinical manifestation. A better understanding of the cellular origins and molecular pathways underlying this heterogeneity is needed to improve patient stratification and treatment. Here, we conducted an integrated genomic and transcriptomic analysis of 124 thymomas and 13 thymic carcinomas, including 20 newly sequenced cases combined with 117 cases from publicly available datasets. This approach stratified TETs into three subgroups with different possible origins: GTF2I-mutant (GTF2I-type) thymomas, copy number-altered (CN-type) thymomas, and thymic carcinomas.

Study EGAS00001004227

Integrated Single-Nucleus and Spatial Transcriptomics Elucidate Heterogeneity and Hypoxia-Driven Organization of Supratentorial Ependymoma

Supratentorial ependymomas are often life-threatening brain tumours that are characterised by significant molecular heterogeneity. In this study, single-nucleus (n = 63) and spatial transcriptomics (n = 30) was performed to delineate the cellular and spatial landscape of supratentorial ependymoma. This study characterises the transcriptional consensus programs of this entity and connects them to clinical outcome. Two previously undescribed programs – associated with the remodelling of the extracellular matrix and the ZFTA fusion identity – are shown to be related to highly unfavourable outcome and to be exclusive to ZFTA fusion-positive tumours. Also, Hypoxia is proposed as the potential driver of spatial organisation, which may affect treatment success.

Study EGAS50000001318

ROBUST (NCT02285062)

The ROBUST clinical trial is a Phase III, randomized, double-blind, placebo-controlled study designed to compare the efficacy and safety of lenalidomide plus R-CHOP chemotherapy (R2-CHOP) versus placebo plus R-CHOP in newly diagnosed Diffuse Large B-cell Lymphoma (DLBCL). Molecular data was collected for all patients at screening, but the only patients of the Activated B-cell (ABC) cell-of-origin subtype were eligible for study inclusion and clinical follow-up. We have performed unsupervised clustering on this cohort and identified 7 novel transcriptional subtypes of DLBCL, one of which represents a high-risk subset of patients with high MYC expression, ABC-associated biology, and low immune infiltration.

Study EGAS50000000333

Guardians_of_the_genome__protecting_DNA_from_endogenous_sources_of_damage_

Analysis of mutational signatures caused by DNA repair defects in human induced pluripotent stem (iPS) cells. A reference human iPS cell line will be used for genetic manipulation to introduce homozygous knockouts of 100 genes known to be involved in or connected to DNA repair or DNA editing. Following a defined period of growth after homozygous knockout of each gene, sub clones will be generated and sequenced. The progenitor “parental” IPS cell line will be used to generate reference sequence data, in order to determine the mutational signature acquired due to the gene knockout. This is a pilot study to investigate the effects of oxygen conditions and growth period on mutations acquired

Study EGAS00001000874

Clonal selection after gene therapy in sickle cell disease

While gene therapy (GT) provides a potentially curative treatment option for patients with sickle cell disease (SCD), the occurrence of myeloid malignancies in clinical trials has prompted concern. To interrogate potential mechanisms underlying increased cancer risk, we used hematopoietic stem cell (HSC) clonal tracking by whole genome sequencing (WGS) to map the somatic mutation and clonal landscape of 2,592 gene modified as well as unmodified single stem and progenitor cells from six SCD patients undergoing gene therapy (7-26 years old, average 12.7× depth). Pre-GT phylogenetic trees in SCD were highly polyclonal and mutation burdens per cell were elevated in some, but not all, patients. Post-GT, no clonal expansions were identified. However, an increased frequency of driver mutations associated with myeloid neoplasms or clonal hematopoiesis (DNMT3A- and EZH2-mutated clones in particular) were seen in both genetically modified and unmodified cells suggested positive selection of mutant clones during gene therapy. This work sheds light on the mutation landscape and HSC clonal dynamics in gene therapy for SCD and highlights enhanced fitness of some HSCs harboring pre-existing driver mutations following gene therapy. Future studies should define the long-term fate of mutant clones including any contribution to expansions associated with myeloid neoplasms.

Dataset EGAD00001010914

Aspirin and Inflammation: Mutations, Genes, Pathways and Prevention in Barrett's Esophagus

Background: Use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) has been shown to protect against tetraploidy, aneuploidy, and chromosomal alterations in the metaplastic condition Barrett's esophagus (BE) and to lower the incidence and mortality of esophageal adenocarcinoma (EA). The esophagus is exposed to both intrinsic and extrinsic mutagens resulting from gastric reflux, chronic inflammation and exposure to environmental carcinogens such as those found in cigarettes. Here we test the hypothesis that NSAID use inhibits accumulation of point mutations/indels during somatic genomic evolution in BE. Methods: Whole exome sequences were generated from 82 purified epithelial biopsies and paired blood samples from a cross-sectional study of 41 NSAID users and 41 nonusers matched by sex, age, smoking, and continuous time using or not using NSAIDs. Results: NSAID use reduced overall frequency of point mutations across the spectrum of mutation types, lowered the frequency of mutations even when adjusted for both TP53 mutation and smoking status, and decreased the prevalence of clones with high variant allele frequency. Never smokers who consistently used NSAIDs had fewer point mutations in signature 17, which is commonly found in EA. NSAID users had on average a 50% reduction in functional gene mutations in nine cancer-associated pathways and also had less diversity in pathway mutational burden compared to nonusers. Conclusions: These results indicate NSAID use functions to limit overall mutations on which selection can act and supports a model in which specific mutant cell populations survive or expand better in the absence of NSAIDs. Galipeau PC, et al. Genome Med. 2018 Feb 27;10(1):17. PMID: 29486792.

Study phs001654

Kids First Pediatric Research Study in Familial Predisposition to Hematopoietic Malignancies (SJFAMILY-HM)

The Gabriella Miller Kids First Pediatric Research Program (Kids First) is a trans-NIH effort initiated in response to the 2014 Gabriella Miller Kids First Research Act and supported by the NIH Common Fund. This program focuses on gene discovery in pediatric cancers and structural birth defects and the development of the Gabriella Miller Kids First Pediatric Data Resource (Kids First Data Resource). All of the WGS and phenotypic data from this study are accessible through dbGaP and kidsfirstdrc.org, where other Kids First datasets can also be accessed. Acute lymphoblastic leukemia (ALL) is the commonest childhood tumor and a leading cause of cancer death in children, adolescents and young adults. Hodgkin and non-Hodgkin lymphoma are also important hematologic malignancies (HM) that occur in children. Each are genetic diseases with growing evidence for a germline predisposition of both familial and sporadic cases, however the inherited genetic basis of ALL/lymphoma are poorly understood. Such knowledge is essential to gain mechanistic insight into the basis of tumor formation, and to guide genetic counseling and genetic management. Here we have assembled a large collection of familial HM kindreds, and extended recurrence cohorts of ALL and HL which will be used to identify the genetic basis of familial HM, examine the frequency of germline variants in sporadic ALL and HL, and to integrate inherited and somatic genomic data. These studies have high potential to provide fundamental new insights into the inherited genetic basis of HM, to provide important information to guide clinical management, and to provide an invaluable public resource of genomic data.

Study phs001738

A Missense SNP in the Tumor Suppressor SETD2 Reduces H3K36me3 and Mitotic Spindle Integrity in Drosophila

While examining DNA from renal cell carcinoma (RCC) patients we observed a single nucleotide polymorphism (SNP; rs58906143,chr3:47163422 C→G (hg19); E902Q*) within SETD2 that was overrepresented in kidney cancer patients compared to control patients. This original study utilized directed sequencing of 14 genes. In an expanded study using a Taqman assay to study the specific SNP, a G allele was found in 72/493 cases (14.6%) and 24/356 (6.7%) controls. Analysis by ancestry revealed that there was there was a G allele in 50/119 (42.0%) cases and 21/71 (29.6%) controls in patients with African Ancestry while there was a G allele in 19/335 cases (5.7%) and 3/269 (1.1%) controls in patients with European Ancestry. These differences did not reach statistical significance. Concurrently, we studied the functional effect of this SNP in a Drosophila model. The homologous amino acid substitution at E741Q reduces H3K36me3 levels which could be rescued by wild type Set2. Additionally, the mutation resulted in significant defects in spindle morphogenesis, consistent with a role for SETD2 in alpha-tubulin methylation during mitosis. Data available through dbGAP include the 14 gene sequence files of 52 control and 128 RCC patients, the results of Taqman SNP (rs58906143) analysis in text files for 221 controls and 357 RCC patients, and compiled phenotype data including age and assigned race. Due to data use limitations, genotyping data for 8 RCC patients and 83 controls as well as GWAS data for ancestry determination will not be available on dbGaP, but will be made available on request.

Study phs003474

Immunohistochemical and molecular pathological search in gastrointestinal tumors

Purpose: RSPO fusions are recently identified recurrent genetic alterations in colorectal cancer (CRC), which lead to WNT pathway activation and are potential therapeutic targets. We aimed to investigate the clinicopathological and molecular features of RSPO fusion-positive CRCs. Experimental Design: We screened 1019 CRCs for RSPO fusions using multiplex reverse transcription polymerase chain reaction. RSPO fusion-positive tumors were characterized for their clinicopathological features and subjected to whole exome sequencing (WES). Results: Our analysis identified 29 CRCs with RSPO fusions (2.8%), consisting of 5 with an EIF3E-RSPO2 fusion and 24 with PTPRK-RSPO3 fusions. The patients were 17 females and 12 males with the median age of 64 years. Thirteen tumors were located in the right colon, 8 were in the left colon, and 8 were in the rectum. Histologically, most of the tumors (24/29, 83%) were classified as adenocarcinomas, not otherwise specified. However, about half of the tumors (13/29, 45%) had a focal or extensive mucinous component, which is significantly more frequent compared with RSPO fusion-negative tumors (13%; p = 8.1 �� 10-7). Four tumors (14%) were mismatch repair-deficient, three of which were associated with MLH1 promoter methylation. WES identified KRAS, BRAF, and NRAS mutations in a total of 27 cases (93%). In contrast, pathogenic mutations in major WNT pathway genes other than RSPO fusions were virtually absent. The presence of an RSPO fusion tended to show shorter overall and recurrence-free survivals in stage II and III patients although the differences were not significant. Conclusions: RSPO fusion-positive CRCs constitute a rare subgroup of CRCs with several characteristic clinicopathological and genetic features. The mutual exclusivity with other WNT pathway gene alterations supports RSPO fusions as valid therapeutic targets in CRC.

Study JGAS000538

12167 results for "cancer rna-seq"

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