3885 results for "*geneti*"

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• Poly(A) RNA sequencing of hepatocellular carcinoma tumors and their matched noncancerous liver tissues

  Background & Aims: The differentiation of distinct multifocal hepatocellular carcinoma (HCC): multicentric disease vs. intrahepatic metastases, in which the management and prognosis varies substantively, remains problematic. We aim to stratify multifocal HCC and identify novel diagnostic and prognostic biomarkers by performing whole genome and transcriptome sequencing, as part of a multi-omics strategy Methods: A complete collection of tumour and somatic specimens (intrahepatic HCC lesions, matched non-cancerous liver tissue and blood) were obtained from representative patientswith multifocal HCC exhibiting two distinct postsurgical courses. Whole-genome and transcriptome sequencing with genotyping were performed for each tissue specimen to con-trast genomic alterations, including hepatitis B virus integrations, somatic mutations, copy number variations, and structural variations. We then constructed a phylogenetic tree to visualise individual tumour evolution and performed functional enrichment analyses on select differentially expressed genes to elucidate biological processes involved in multifocal HCC development. Multi-omics data were integrated with detailed clinicopathological information to identify HCC biomarkers, which were further validated using a large cohort of HCC patients (n = 174).Results: The multi-omics profiling and tumour biomarkers could successfully distinguish the two multifocal HCC types, while accurately predicting clonality and aggressiveness. The dual specificity protein kinase TTK, which is a key mitotic checkpoint regulator with links to p53 signaling, was further shown to be a promising overall prognostic marker for HCC in the large patient cohort.Conclusions: Comprehensive multi-omics characterisation of multifocal tumour evolution may improve clinical decision-making, facilitate personalised medicine, and expedite identification of novel biomarkers and therapeutic targets in HCC.

  Study EGAS00001002337

• Germline biallelic mutation affecting the transcription factor Helios causes pleiotropic defects of immunity

  We studied a patient with recurrent respiratory infections and hypogammaglobulinemia and identified a germline homozygous missense mutation in IKZF2 encoding Helios (p.Ile325Val). We show that HeliosI325V retains DNA-binding and dimerization properties, but loses interaction with several partners, including epigenetic remodelers HDAC1, HDAC3 and the ATAC complex. Single-cell RNA-sequencing of peripheral blood mononuclear cells revealed gene expression signatures indicative of a shift towards pro-inflammatory, effector-like status in the patient’s T cells. We observed an upregulation of the anti-inflammatory gene, TSC22D3, encoding the glucocorticoid-induced leucine zipper (GILZ), whose expression was reported to increase upon IL-2 deprivation. We validated this finding in primary T cells, where we observed a pronounced reduction in IL-2 production upon their stimulation, together with a defect in their ability to proliferate, rendering them more anergic. Collectively, we identify a novel germline-encoded inborn error of immunity and define a role for Helios in conventional T cells, whereby interactions with specific binding partners is necessary to mediate the transcriptional programs that enable T-cell homeostasis in health and disease.

  Study EGAS00001005675

• In this study, we performed exon sequencing (WXS) of 80 paired Brain cancer tumors and adjacent normal tissues to identify novel potential biomarkers. We extracted mutational signatures which induce somatic mutations . Our study covers a comprehensive genetic framework that can be used in clinical trials and treatment modalities in Brain cancer.

  In this study, we performed exon sequencing (WXS) of 80 paired Brain cancer tumors and adjacent normal tissues to identify novel potential biomarkers. We extracted mutational signatures which induce somatic mutations . Our study covers a comprehensive genetic framework that can be used in clinical trials and treatment modalities in Brain cancer.

  Study EGAS00001002352

• Botswana 15 autosomal unlinked microsatellites

  Population structure was investigated in 990 Botswana individuals according to ethno-linguistics, Bantu and Khoisan, and geography (the nine administrative districts) using the AmpFLSTR Identifiler autosomal microsatellite markers. Genetic diversity and forensic parameters were calculated for the overall population, and according to ethno-linguistics and geography. The overall combined power of exclusion (CPE) was 0.9999965412 and the combined match probability 6,28 x 10-19. CPE was highest for the Khoisan Tuu ethnolinguistic group and the Northeast District at 0.9999582029 and 0.9999922652 respectively. CMP ranged from 6.28 x 10-19 (Khoisan Tuu) to 1,02 x 10-18 (Northwest district). Using pairwise genetic distances (FST), analysis of molecular variance (AMOVA), factorial correspondence analysis (FCA), and the unsupervised Bayesian clustering method found in STRUCTURE and landscape genetics software TESS, ethno-linguistics were found to have a greater influence on population structure than geography. FCA showed clustering between Bantu and Khoisan, and within the Bantu. This Bantu sub-structuring was not seen with STRUCTURE and TESS, which detected clustering only between Bantu and Khoisan. The patterns of population structure revealed highlight the need for regional reference databases that include ethno-linguistic and geographic location information. These markers have important potential for bio-anthropological studies as well as for forensic applications.

  Study EGAS00001002380

• The identification of genetic vulnerabilities in head and neck cancers for the development of novel treatments.

  The global cancer burden is expected to double by the year 2030 and this will disproportionately affect the Asian continent. Head and neck squamous cell carcinoma (HNSCC) is endemic in Asia. It is the sixth most common cancer worldwide and the second most common in Malaysia, with approximately 600,000 new cases per year globally. Longterm survival remains less than 50%, underscoring the need for better therapeutic strategies. In this proposal we aim to bring new technological advancements in the identification of critical genes in HNSCC and the identification of compounds for the development of new therapies in HNSCC. We propose to genomically characterise 16 unique Asian H&N cancer cell lines, to classify sub groups where identification of essential genes that can be targeted for tumor control can be applied in a more rational way. Further, we propose to use zebrafish, an established drug discovery platform to identify promising pathway-specific compounds that could be further studied using CRISPR/Cas9 lethality screens and biological models to better identify novel therapeutic strategies to combat this major health problem in Asia.

  Study EGAS00001002682

• Chromatin_accessability_in_cytokine_induced_immune_cell_states

  We isolated T cells and monocotyes from healthy platelet donors and cultured them in resting and stimulated conditions with addition of a range of cytokines. We performed K27Ac ChM sequencing to assess the chromatin activity in different cytokines treated cells. These cellular profiles were used to map risk variants to the cytokine-induced cell states relevant for autoimmune diseases.

  Study EGAS00001002749

• Suppressors and activators of JAK-STAT signaling at diagnosis and relapse of acute lymphoblastic leukemia in Down Syndrome

  Children with Down Syndrome (DS) are prone to development of high risk B-cell precursor ALL (DS-ALL) that differs genetically from most sporadic pediatric ALLs. Increased expression of CRLF2, the receptor to thymic stromal lymphopoietin (TSLP) characterizes about half of DS-ALLs and also a subgroup of sporadic “Philadelphia-like ALLs”. To understand the pathogenesis of relapsed DS-ALL we performed integrative genomic analysis of 25 matched diagnosis remission and relapse DS-ALLs. We found that the CRLF2 rearrangements are early events during DS-ALL evolution and generally stable between diagnoses and relapse. Secondary activating signaling events in JAK-STAT/RAS pathway were ubiquitous but highly redundant between diagnosis and relapse, suggesting that signaling is essential but that no specific mutations are “relapse driving”. We further found that activated JAK2 may be naturally suppressed in 25% of CRLF2 positive DS-ALL by loss-of-function aberrations in USP9X, a deubuitinase previously shown to stabilize the activated phosphorylated JAK2. Interrogation of large ALL genomic databases extended our findings up to 25% of CRLF2 positive, “Ph like” ALLs. Pharmacological or genetic inhibition of USP9X as well as treatment with low-dose Ruxolitinib enhanced the survival of pre-B ALL cells overexpressing mutated JAK2. Thus, somehow counterintuitive, we found that suppression of JAK-STAT “hyper-signaling” may be beneficial to leukemic B cell precursors. This and the reduction of JAK mutated clones at relapse suggest that the therapeutic effect of JAK specific inhibitors may be limited. Rather, combined signaling inhibitors or direct targeting of the TSLP receptor may be a useful therapeutic strategy for DS-ALL.

  Study EGAS00001002410

• H3Africa - Genomic and Environmental Risk Factors for Cardiometabolic Disease in Africans

  The long-term vision of the AWI-Gen Collaborative Centre (CC) is to build sustainable capacity in Africa for research that leads to an understanding of the interplay between genetic, epigenetic and environmental risk factors for obesity and related cardiometabolic diseases (CMD) in sub-Saharan Africa. The CC will be consolidated under the auspices of the University of the Witwatersrand (Wits) and the International Network for the Demographic Evaluation of Populations and Their Health in Developing Countries (INDEPTH). It will capitalize on the unique strengths of existing longitudinal cohorts, including the urban Soweto and rural Agincourt studies in South Africa (Wits based), and the well established INDEPTH demographic health and surveillance centers in Kenya, Ghana, Burkina Faso and South Africa. The centers offer established infrastructure, trained fieldworkers, long-standing community engagement, and detailed longitudinal phenotypic data, focusing on obesity and cardiometabolic health. Key strengths are harmonized phenotyping across sites, building on strong existing cohorts, and representation of the geographic and social variability of African populations. We aim to: 1. Build sustainable infrastructure (biobanks and laboratories) and capabilities (well characterized population cohorts, genotyping and bioinformatics) for genomic research on the African continent; 2. Understand the genomic architecture of sub-Saharan populations from west, east and south Africa to guide genomic studies (genome sequencing and high throughput SNP and CNV arrays using unrelated individuals and family trios to improve the accuracy of haplotype analyses) and; 3. Investigate the independent and synergistic genomic contributions to body fat distribution (BMI, hip/waist circumference, subcutaneous and visceral fat) in these populations considering the relevant environmental and social contexts (rural/urban communities, quickly transitioning obesity prevalence, differential HIV, TB, and malaria infection histories). We will investigate the effect of obesity and fat distribution on the risk for CMD in the longitudinal cohorts.

  Study EGAS00001002482

• Cell fate mapping of human glioblastoma reveals an invariant stem cell hierarchy pre- and post-treatment

  Human glioblastomas (GBMs) are thought to harbour a subpopulation of glioblastoma stem cells (GSCs) that initiate tumour formation and regrowth following treatment. However, the origin of their proliferative heterogeneity during tumour growth pre- and post-treatment remains poorly understood. Here we study the clonal evolution of DNA barcoded GBMs following their serial propagation in xenograft mouse models to define the fate behaviour of individual GBM cells. Through quantitative analysis of clone sizes scored across multiple passages, we show that the growth of GBM clones in vivo are consistent with a remarkably neutral process resulting from a conserved proliferative hierarchy. In this model, slow-cycling stem-like cells give rise to a more rapidly cycling progenitor population with extensive self-maintenance capacity, that in turn generates short-lived cells that lack proliferative ability. We also identify rare "outlier" clones that deviate from these dynamics, and further show that chemotherapy reproducibly facilitates the selective expansion of pre-existing drug-resistant GBM lineages. Finally, we show that coexisting, functionally distinct GSCs may be targeted separately with epigenetic compounds. These findings show that, independent of an evolving mutational signature, the clonal dynamics of human GBM can be surprisingly robust, with intratumoural heterogeneity derived primarily from the defined stochastic fate behaviour of tumour cells within a conserved proliferative hierarchy.

  Study EGAS00001002424

• Integrative genomic and transcriptomic analysis of adult leiomyosarcoma (HIPO-028, HIPO-018, HIPO-021)

  Leiomyosarcoma (LMS) is an aggressive mesenchmyal malignancy with few therapeutic options. The mechanisms underlying LMS development, including clinically actionable genetic vulnerabilities, are largely unknown. We performed genomic and transcriptomic profiling of a large cohort of LMS tumors and identified substantial mutational heterogeneity, near-universal inactivation of TP53 and RB1, widespread DNA copy number alterations, chromothripsis, and frequent whole-genome duplication. Furthermore, we discovered recurrent alterations in telomere maintenance genes such as ATRX, RBL2, and RPA1, resulting in alternative lengthening of telomeres in 78% of cases. Finally, most tumors displayed hallmarks of “BRCAness”, including alterations in various homologous recombination DNA repair genes, multiple structural rearrangements, and enrichment of specific mutational signatures, and cultured LMS cells were sensitive towards olaparib and cisplatin treatment. This first comprehensive study of genetic alterations in LMS has uncovered key biological features that may inform future experimental research and enable the design of novel therapeutic strategies for this disease.

  Study EGAS00001002437