3922 results for "*geneti*"

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• WES Analysis of precancerous lesions in Lynch Syndrome

  The project focuses on identifying the genetic alterations involved in the early stages of tumor development in individuals with Lynch Syndrome. Using Whole Exome Sequencing (WES), the study aims to characterize somatic mutations and molecular pathways that drive the transformation from normal tissue to precancerous lesions. This research contributes to a better understanding of tumorigenesis in hereditary colorectal cancer syndromes.

  Study EGAS50000001546

• RBMX functional retrocopy safeguards brain development

  Retrotransposition has generated thousands of intronless gene copies in mammalian genomes, yet their contribution to brain development and evolution remains largely unexplored. We investigated the role for RBMX retrocopy in shaping neurodevelopment and modulating disease. First, we reported 8 distinct pathogenic variants in RBMX, an X-linked splicing regulator, in 11 males presenting with intellectual disability, microcephaly, and cortical malformations. Then, we combined transcriptomic profiling, protein–protein and protein–RNA interaction studies both in human cellular models and mouse embryonic cortices to assess the functional redundancy between RBMX and its retrocopy RBMXL1. Finally, we use mouse genetics to dissect RBMX function and its compensation by RBMXL1 in corticogenesis. We show that RBMX pathogenic variants disrupt cortical development through both loss- and gain-of-function mechanisms. Surprisingly, despite severe phenotypes in humans, Rbmx-deficient mice display only mild cortical abnormalities, a discrepancy likely due to compensation by Rbmxl1, a retrocopy that arose independently in mice and humans. We demonstrate that RBMX and RBMXL1 share protein and RNA partners and act redundantly in brain development, with RBMXL1 buffering the impact of RBMX deficiency. Together, these findings establish that RBMXL1 functions as a functional paralog of RBMX safeguarding neurodevelopment by buffering deleterious variation. More broadly, these results identify retrocopies as active contributors to neurodevelopmental robustness and suggest that functional retrocopies may have facilitated the evolutionary diversification of the mammalian brain.

  Study EGAS50000001650

• Monosomy 7 delineates a primitive acute myeloid leukemia with adverse prognosis and responsiveness to epigenetic therapy

  The mechanistic basis for adverse risk associated with monosomy 7 remains undetermined in AML. In contrast to del(7q), monosomy 7 conferred adverse prognosis independent of TP53 and complex karyotype. Single-cell RNA and ATAC-seq revealed an epigenetically remodeled landscape and expansion of multipotent progenitor (MPP)-like cells. Monosomy 7 derived progenitors were distinguished by reduced chromatin accessibility and expression of STK17A and NT5C3A, which conferred resistance to cytotoxic and venetoclax-based therapy. To circumvent resistance mediated by monosomy 7 and deficient TP53, histone deacetylase inhibitors (HDACi) effectively restored apoptotic potential and augmented the activity of venetoclax. In a randomized clinical trial including older unfit patients with AML and monosomy 7, responses were observed in the majority that received low-dose cytarabine, venetoclax and the HDACi pracinostat, some with durable remissions exceeding 3 years. Longitudinal studies highlighted diminution of MPP-like cells, linking epigenetic remodeling to clinical response and therapeutic vulnerability of monosomy 7 AML.

  Study EGAS50000001641

• Monosomy 7 delineates a primitive acute myeloid leukemia with adverse prognosis and responsiveness to epigenetic therapy

  The dataset comprises 27 single-cell multiome (ATAC + GEX) datasets generated from 13 patients with AML, collected across different stages of disease progression. In addition, matched long-read sequencing data from 5 samples were used to enable longitudinal analyses throughout the manuscript. Finally, bulk RNA-seq and ATAC-seq datasets from the cell line used in this study are also included.

  Dataset EGAD50000002359

• Translational analyses from a phase II study of pembrolizumab and epigenetic modification with azacitidine in platinum-resistant epithelial ovarian cancer

  Epigenetic modulators may sensitize platinum-resistant ovarian cancer (PROC) to immune checkpoint inhibition by reprogramming the tumor microenvironment. We report clinical and translational findings from a phase II non-randomized study of pembrolizumab and oral azacytidine in 34 women with PROC (NCT02900560). The effect of combined epigenetic and immunotherapy was evaluated by transcriptomic analyses of serially biopsied tumors. Differential gene expression analyses revealed an upregulation of inflammatory and cytolytic genes and co-inhibitory checkpoints 6 weeks on-therapy. Upregulation of interferon signaling, antigen presentation and immune cell adhesion and migration gene sets was prominent on-therapy, together with an increased density of CD8+ T -cells. Patients with a CA-125 and/or clinical response showed an enrichment of adaptive and conserved immune response gene sets on-therapy.

  Study EGAS50000001165

• Case Report: Pre-Clinical Combination Targeting VEGF and PI3K in a Rare, Aggressive Mixed Endometrial Carcinoma

  We report a rare case of a young patient (VENUS 167) initially diagnosed with grade 1 endometrioid endometrial cancer, which, following endocrine treatment, presented with mixed aggressive carcinoma with three distinct histologic patterns: grade 1 endometrioid, large cell neuroendocrine, and undifferentiated carcinoma. The surgical specimen at the time of disease progression was used to establish OPTO.85, a patient-derived organoid (PDO), followed by a corresponding organoid-derived xenograft (ODX). Multi-omic analyses confirmed that OPTO.85 accurately reflected the patient’s tumor characteristics. WES analysis identified oncogenic alterations in PIK3CA, ARID1A, and CTNNB1. Further RNA-seq and ATAC-seq analyses revealed enrichment in VEGF and Wnt signaling pathways, suggesting therapeutic vulnerabilities. A high-throughput drug screen was conducted using ApexBio-Approved and Epigenetic Drug Libraries, along with Kinase Inhibitor and Tool Compound Libraries developed at the Ontario Institute of Cancer Research. The OPTO.85 PDO exhibited sensitivity to PI3K inhibitors and responsiveness to VEGF inhibition. Cediranib demonstrated synergy with BKM120, significantly reducing organoid growth. This combination also showed in vivo efficacy in the ODX model, where dual inhibitors significantly suppressed tumor growth compared to single compounds. This case exemplifies the impact of genomic profiling and patient-derived models in identifying actionable molecular changes in rare cancers with limited therapeutic options and poor prognosis. It highlights that high-throughput sequencing for individual patient tumors and generation of patient-derived models are feasible in endometrial cancer. This preclinical model may assist clinical decision and personalized therapy requiring validation in prospective studies.

  Study EGAS50000001665

• Khoe-San Genome Project

  The dataset contains BAM files of whole genome sequencing data of African Khoe-San population (n=169, 30X coverage) recruited from South Africa and Namibia. The population captured the true extent of human genetic diversity as represent the earliest diverged human population. The project described a detailed divergence of human population and identified positive selections associated forager lifestyles in Khoe-San population. These findings emphasise an inclusive catalogue with better representation of the earliest human genomic diversity to better advance biomedical research.

  Study EGAS50000001408

• Single-cell multi-omics and mtDNA genotyping of human peripheral blood cells

  In this study, we characterize human peripheral blood cells using mitochondrial single-cell ATAC-seq (mtscATAC-seq), which simultaneously profiles mitochondrial genomes and chromatin accessibility at single-cell resolution. This submission includes PBMCs from one healthy pediatric donor and one 80-year-old patient diagnosed with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome.

  Study EGAS50000001020

• Whole genome sequencing data of paediatric hyperdiploid acute lymphoblastic leukemia

  The hyperdiploid (HeH) subtype with 51–67 chromosomes is the most common subtype in childhood, presented in 25–30% of the cases, and is associated with excellent prognosis . The HeH subtype harbors relatively few additional genetic alterations, suggesting that extra chromosomes are the driving event for leukemia onset. Secondary hits usually affect the RAS signaling pathway and histone modifiers.

  Study EGAS50000001690

• Recurrent somatic DICER1 mutations in non-epithelial ovarian tumors

  Background: Germline truncating mutations in DICER1, an RNase III-type endoribonuclease essential for processing of microRNAs, are seen in families with the pleuropulmonary blastoma-family tumor and dysplasia syndrome; these individuals have a propensity to develop non-epithelial ovarian tumors (i.e. sex-cord stromal and germ cell tumors). Methods: We sequenced the whole transcriptomes or exomes of 14 non-epithelial ovarian tumors and noted closely clustered mutations in the RNase IIIb domain of DICER1 in four cases. Using Sanger sequencing, we then analyzed additional ovarian tumors for mutations in this region. The impact of the mutations on the enzymatic activity of Dicer1 was determined using in vitro RNA cleavage assays. Results: RNase IIIb domain DICER1 mutations were found in 30/102 non-epithelial ovarian tumors (29%), predominantly Sertoli-Leydig cell tumors (26/43, 60%), including 4/4 from individuals with germline DICER1 mutations. The mutations were restricted to metal binding sites within the RNase IIIb catalytic centres critical for miRNA interaction and cleavage, and were somatic in all 14 cases where germline DNA was available for testing. Of 266 epithelial ovarian and endometrial cancers tested, one case, an ovarian carcinosarcoma, had a hotspot mutation. In vitro, the mutant DICER proteins showed reduced RNase IIIb activity but retained RNase IIIa activity. Conclusions: Somatic missense mutations of the RNase IIIb domain of DICER1 are common in non-epithelial ovarian tumors. Genetic, pathologic, and functional evidence suggest that these mutations do not obliterate DICER1 function, rather, they alter it in specific cell types, a novel mechanism through which perturbed microRNA expression is oncogenic.

  Study EGAS00001000135