4076 results for "*geneti*"

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• The landscape of Usher syndrome-associated transcript isoforms in the human neural retina

  Usher syndrome is an autosomal recessively inherited disorder characterized by the combination of progressive loss of visual function due to retinitis pigmentosa, sensorineural hearing loss and vestibular dysfunction in a subset of cases. Usher syndrome is clinically and genetically heterogeneous. To date, eleven genes have been identified that are associated with Usher syndrome. It is known that these genes express multiple isoforms, however, for most of the known isoforms their relative importance in the human retina is unknown. To fill this gap, using PacBio long-read mRNA sequencing we aimed to provide an overview of the Usher syndrome transcripts in the human retina.

  Study EGAS50000000504

• SCLC MeDIP

  Mimicry of neuronal features are emerging as malignant regulators of cancer growth and metastasis. Neuroendocrine (NE) cancers and small cell lung cancers (SCLC) in particular have been shown to share expression profiles marking various stages of neuronal differentiation. Here, methylation profile from SCLC patients' tumour and normal tissue has been investigated genome wise.

  Study EGAS50000000506

• Profiling Genome-Wide DNA Methylation Patterns in Human Aortic and Mitral Valves

  Study EGAS00001004559

• Plasma mutation profile of precursor lesions and colorectal cancer using the Oncomine Colon cfDNA Assay

  Colorectal cancer (CRC) is the second leading cause of cancer death worldwide. Early detection of precursor lesions or early-stage cancer could hamper cancer development or improve survival rates. Liquid biopsy, which detects tumor biomarkers, such as mutations, in blood, is a promising avenue for cancer screening. To assess the presence of genetic variants in plasma cell-free tumor DNA from patients with precursor lesions and colorectal cancer using the commercial Oncomine Colon cfDNA Assay. Cell-free DNA (cfDNA) samples from the blood plasma of 52 Brazilian patients were analyzed. Eight patients did not have any significant lesions (five normal colonoscopies and three hyperplastic polyps), 24 exhibited precursor lesions (13 nonadvanced adenomas, ten advanced adenomas, and one sessile serrated lesion), and 20 patients with cancer (CRC). The mutation profile of 14 CRC-associated genes were determined by next-generation sequencing (NGS) using the Oncomine Colon cfDNA Assay in the Ion Torrent PGM/S5 sequencer.

  Study EGAS50000000471

• ATACseq - Notch Signaling Maintains a Progenitor-Like Subclass of Hepatocellular Carcinoma

  To assess how Notch inhibition impacts chromatin accessibility and how chromatin changes relate to HNF4A and CEBPA activities, we performed Assay-for-Transposase-Accessible-Chromatin (ATAC) sequencing of LIV78 tumors, 72 hours after treatment with NOTCH2 blocking or control antibodies. Our TF activity and chromatin analyses thus lead to a model in which Notch inhibition leads to increased expression of CEBPA, thus enabling CEBPA to partner with HNF4A to jointly drive transcriptional programs and the underlying chromatin rearrangements that promote differentiation of progenitor-like tumor cells to a mature hepatocyte fate incompatible with tumor growth and maintenance.

  Study EGAS50000000516

• Contribution of specific cell types to the development of Barrett’s esophagus and carcinoma via germline genetic risk

  This study was designed to elucidate how individual cell types in Barrett’s esophagus (BE) and esophageal adenocarcinoma (EAC) contribute to disease development via germline genetic risk. We performed single cell RNA-sequencing (scRNA-seq) of BE, EAC and paired normal esophagus and gastric fundus tissue samples. After analyzing individual cell types, we integrated the scRNA-seq data and data of a genome-wide association study (GWAS) on BE/EAC to determine cell type-specific genetic risk. Raw data from the RNA-sequencing is provided here.

  Study EGAS50000000530

• Pipeline Olympics: Continuous benchmarking of computational workflows for DNA methylation sequencing data

  DNA methylation is a widely studied epigenetic mark and a powerful biomarker of cell type, age, environmental exposure, and disease. Genome-wide DNA methylation profiling is usually performed using whole-genome sequencing following selective conversion of unmethylated cytosines into thymines via bisulfite treatment or enzymatic methods. Numerous software tools facilitate processing of raw sequencing data for DNA methylation profiling, but a comprehensive benchmarking has been lacking. In this study, we systematically compared methods and tools for processing DNA methylation sequencing data. We established a dedicated benchmarking dataset comprising genome-wide DNA methylation profiling data for four reference samples using five experimental protocols each. The results of data processing were compared to highly quantitative locus-specific DNA methylation measurements available for 46 genomic loci. Based on this gold-standard reference dataset, we identified workflows that consistently demonstrated high performance. We present our results in an interactive application that provides a “living benchmark” ready for continuous updating as new workflows are proposed and require benchmarking against existing methods. In summary, our study provides guidance for any laboratory studying DNA methylation on a genome-wide scale.

  Study EGAS50000000541

• Single cell RNA and ATAC sequencing data from GBM patients

  Glioblastoma cells infiltrate and incorporate into the normal brain parenchyma. We conduct unbiased multimodal single-cell and spatial sequencing to capture GBM cells and the surrounding tumor microenvironment using a regional sampling strategy. For each patient, we profile the peritumoral region, tumor edge, and tumor core, providing a comprehensive characterization of the transcriptional and epigenetic landscape of GBM spatial heterogeneity, with a specific focus on infiltrative cells.

  Study EGAS50000000547

• Sex Differences in MAGEL2 Gene Promoter Methylation in High Functioning Autism - Trends from a Pilot Study Using Nanopore Cas9 Targeted Long Read Sequencing

  Using DNA extracted from peripheral blood, Cas9-targeted nanopore DNA sequencing was used to analyze MAGEL2 gene, including its entire regulatory construct (chr15:23639316-23651466), for sequence variation and 5-methyl-cytosine (5mC) modification in a cohort of adults with HFA compared to sex- and age-matched NC.

  Study EGAS50000000508

• Rapid brain tumor classification from sparse epigenomic data

  Although the intraoperative, molecular differential diagnosis of the approximately one hundred different brain tumor entities described to date has been a goal of neuropathology in the last decade, this has not yet been achieved in a clinically relevant time frame of less than one hour after biopsy collection. Recent advances in third-generation sequencing technologies have brought this once-elusive goal within reach. However, established machine learning techniques rely on concepts and methods, impractical for live diagnostic workflows in clinical applications. Here, we present MethyLYZR, a Naïve Bayesian framework enabling fully tractable live classification of cancer epigenomes. MethyLYZR can be run in parallel with an ongoing Nanopore experiment with negligible computational cost and provides clinically relevant and accurate cancer classification results within 15 minutes of sequencing. Therefore, only the time required for DNA extraction and the Nanopore sequencer's maximum parallel throughput remain limiting factors for even faster time-to-results. We demonstrate the potential utility of the MethyLYZR framework not only for the neurosurgical intraoperative use case but also for other oncologic indications and cell-free DNA from liquid biopsies.

  Study EGAS50000000559

• 3D genome topology distinguishes molecular subgroups of medulloblastoma

  Medulloblastoma (MB) has four molecular subtypes, but their 3D genome architecture differences are unclear. We used in situ Hi-C on 28 surgical specimens and a patient-derived xenograft to reconstruct the 3D genome architecture of MB subtypes, finding that topologically associating domain (TAD) insulation scores could distinguish MB subtypes.

  Study EGAS50000000540

• Genetic analysis of short stature using whole exome sequencing

  The aim of the study is to find the genetic aetiologies of short stature, using whole-exome sequencing technology.

  Study EGAS50000000578

• A prospective trial comparing adaptive long-read sequencing and short-read genome sequencing for genetic diagnosis of cerebellar ataxia

  This study evaluated the effectiveness of long- and short-read sequencing as diagnostic tools for CA. We recruited 110 individuals (48 females, 62 males) with a clinical diagnosis of CA. Short-read genome sequencing (SR-GS) was performed to identify pathogenic RE and also non-RE variants in 356 genes associated with CA. Long-read adaptive sequencing (LR-AS) was performed to identify pathogenic RE in 67 genes.

  Study EGAS50000000573

• Single-cell targeted DNA-sequencing and protein sequencing

  We performed single-cell targeted DNA sequencing (MissionBio) on 13 high hyperdiploid B-ALL patients at diagnosis to study the genetic heterogeneity. For a number of patients single-cell surface protein antibody sequencing was added (DAB-seq) to better characterize the different cell types. Furthermore, additional samples during treatment were collected and analysed for some patients. In this way we want to study the clonal heterogeneity of these B-ALL samples, based both on mutations and CNVs, and identify resistant clones that could be targeted after relapse.

  Study EGAS50000000580

• Lactate metabolism in cancer stem cell fate regulation

  Tumors arise as a result of uncontrolled cell proliferation driven by mutations in the signaling pathways that regulate the balance between cell division and differentiation. Despite of that, in the tumor, cancer stem cells seem to retain their capability to differentiate, which can lead to differential chemotherapy response. We previously showed that intestinal stem cells and differentiated cells display specific metabolic features and that they interact through metabolites. Moreover, we found that altering mitochondrial metabolism is sufficient to lead and define stem cell differentiation. In cancer, cellular metabolism is highly derailed. However, how metabolic changes in the cancer cell contribute to cell fate decisions remains unknown. Recently, the crosstalk between metabolism and epigenetics has emerged as one of the players in tumor development. Here we aim to address the impact of the altered metabolism of cancer cells on their epigenome as a regulatory axis of cell identity and fate. We use human-derived tumor organoids where we introduce genetic encoded fluorescent-based reporters to visualize cell identity and metabolism at single cell level. We combine 4D live imaging with a recently developed machine learning method to re-construct cell-lineages, trace stem cell state and metabolic changes during tumor organoid development. We find that, mimicking the tumor metabolic microenvironment (Warburg effect-driven low-glucose high-lactate) leads to changes cellular metabolism and histone acetylation. Strikingly, these alterations provoke profound changes in tumor development by increasing the population of cancer stem cells and their proliferation and differentiation dynamics.

  Study EGAS50000000063

• Repeat expansions with small TTTCA insertions in MARCHF6 cause Familial Adult Myoclonus without Epilepsy

  Familial Adult Myoclonic Epilepsy (FAME) is a rare autosomal dominant disorder characterized by cortical tremulous myoclonus and generalized tonic clonic (GTCS) or myoclonic seizures. Intrafamilial variability regarding the prevalence of seizure has been reported. Despite apparent genetic heterogeneity, FAME is caused by the same TTTTA/TTTCA pentanucleotide repeat expansion in introns of seven different genes with no common function. Expansions containing only TTTTA repeats are benign, and only expansions including a TTTCA expansion insertion, which can be located 3' to the TTTTA expansion or in the middle of the TTTTA repeats, are pathogenic. We aimed to identify the underlying genetic cause of dominant cortical myoclonus without GTCS in two unrelated families. We used a combination of repeat-primed PCR, long-range PCR and nanopore sequencing to detect and characterize expansions at known FAME loci. We report a novel configuration of the FAME3 repeat expansion in MARCHF6 segregating with cortical myoclonus without epilepsy GTCS in both families. This expansion predominantly comprises elongated TTTTA repeats, ranging from 388 to 454 repeats, with the presence of only 5-11 TTTCA repeats at its 3' terminus (i.e., 5’-(TTTTA)~388-454(TTTCA)5-11-3’). This configuration exhibits greater stability upon meiotic transmission but somatic variability in TTTCA repeat number was detected at low level in blood. We observed an inverse correlation between the number of TTTCA repeats and the age at myoclonus onset. This study shows that as little as five TTTCA juxtaposed with expanded TTTTA expansions is sufficient to cause cortical myoclonus without GTCS. This finding has implications regarding possible pathophysiological mechanisms leading to FAME.

  Study EGAS50000000570

• Tumor Evolution Analysis Uncovered Immune-Escape Related Mutations in Relapsed Diffuse Large B-Cell Lymphoma

  More than 60% of patients with primary diffuse large B-cell lymphoma (DLBCL) achieve durable remissions upon the chemoimmunotherapy with R-CHOP. However, the outcome of the relapse patients is extremely poor. To characterize the molecular features that underlie treatment resistance, we performed whole-exome sequencing (n=44) and deep targeted sequencing (n=27) of 44 diagnosis-relapse DLBCL pairs. We found that the overall landscape of genetic alterations was concordant between diagnosis and relapse DLBCL. By a deep comparison of the longitudinal sequencings, we identified relapse-enriched mutations that involved in evasion of immune surveillance (CD58, TNFRSF14, PKD1, FAS), resistance to DNA damaging agents (ATM, TP53), and critical tumor suppressor gene (ZFHX3). Knockdown of ATM and ZFHX3 resulted in increased drug resistance in both germinal center B cell like (GCB) and activated B cell like (ABC) DLBCL cell lines in vitro, while the knockdown of TNFRSF14 and FAS conferred resistance specifically in GCB cell lines. Furthermore, we summarized two evolutionary patterns of DLBCL relapse as the “durable retention” model with stable clone structure, and the “selective sweep” model which exhibited significant clonal switch. Of note, genetic alterations leading to attenuated immune responses usually presented as trunk mutations in the “durable retention” model (7/12) while were newly acquired or expanded upon relapse in the “selective sweep” model (9/16). Overall, our study demonstrated that relapse DLBCL derives from distinct clonal evolutionary patterns, and highlighted immune escape as an important contributor of tumor relapse.

  Study EGAS50000000032

• Cas9-targeted-based long-read sequencing for genetic screening of RPE65 locus

  In order to compare sequencing performance of different technologies in a specific locus, we sequenced blood samples of five inherited retinal dystrophies (IRD) patients harboring a monoallelic variant in RPE65 that remained uncharacterized with: 1) Clinical exome targeted sequencing (CES), 2) whole genome sequencing (WGS), and 3) Long-read sequencing on a MinION platform where CRISPR-Cas9 guide RNA probes were designed to target a 31 kb region including the entire RPE65 locus.

  Study EGAS50000000596

• IMPRESS: Improved methylation profiling using restriction enzymes and smMIP sequencing, combined with a new biomarker panel, creating a multi-cancer detection assay

  Background Despite the worldwide progress in cancer diagnostics, more sensitive diagnostic biomarkers are needed. The methylome has been extensively investigated in the last decades, but a low-cost, bisulfite-free detection method for multiplex analysis is still lacking. Methods We developed a methylation detection technique called IMPRESS, which combines methylation-sensitive restriction enzymes and single-molecule Molecular Inversion Probes. We used this technique for the development of a multi-cancer detection assay for eight of the most lethal cancer types worldwide. We selected 1791 CpG sites that can distinguish tumor from normal tissue based on DNA methylation. These sites were analysed with IMPRESS in 35 blood, 111 tumor and 114 normal samples. Finally, a classifier model was built. Results We present the successful development of IMPRESS and validated it with ddPCR. The final classifier model discriminating tumor from normal samples was built with 358 CpG target sites and reached a sensitivity of 0.95 and a specificity of 0.91. Moreover, we provide data that highlight IMPRESS’s potential for liquid biopsies. Conclusions We successfully created an innovative DNA methylation detection technique. By combining this method with a new multi-cancer biomarker panel, we developed a sensitive and specific multi-cancer assay, with potential use in liquid biopsies.

  Study EGAS50000000624

• Comprehensive molecular portrait reveals genetic diversity and distinct molecular subtypes of small intestinal neuroendocrine tumors

  This study aims to characterize neuroendocrine tumors of the small intestine (siNETs) from genomic, transcriptomic, epigenomic, and clinical perspectives. Involving 122 patients and 219 samples, we generated whole-genome sequencing data, RNA sequencing data, genotyping arrays, and methylation arrays to conduct an integrative analysis of this rare tumor type. Our findings identify distinct molecular subtypes that correlate with siNET clinical features.

  Study EGAS50000000642

• H3K27ac ChIP-seq of lung neuroendocrine tumors

  H3K27ac ChIP-seq of lung neuroendocrine tumors

  Study EGAS50000000057

• Bulk ATACseq 7days - Calprotectin in vitro effects on human early hematopoiesis

  To explore the effects of calprotectin (CAL) on early hematopoiesis, we incubated CD34+ cells from four healthy donors for 7 days in the presence of stem cell factor (SCF), FLT3-ligand and thrombopoietin (TPO) without and with CAL, interleukin-6 (IL6) and the IL6_CAL combination before collecting cells. We performed the same experiment with CD34+ cells collected from three patients with JAK2-V617F-mediated myelofibrosis (MF). A total of 135,545 cells from healthy donors and 111,725 cells from myelofibrosis patients were analyzed by single-cell RNA sequencing (scRNA-seq) using the 10X Chromium droplet-based platform. Bulk ATACseq 7days - Normal and tumor samples 4 conditons : -Control - Calprotectin - IL-6 - Calprotectin+IL-6

  Study EGAS50000000456

• Oncogenic FOXL2C134W has gain-of-function chromatin remodeling activity that reprograms glucocorticoid receptor occupancy to promote ovarian granulosa cell tumor growth

  Adult type ovarian granulosa cell tumors (AGCTs) are rare malignancies with near universal somatic mutation c.C402G (p.Cys134Trp) in FOXL2, a forkhead box-family transcription factor important for ovarian function. Relapsed AGCT is incurable and the mechanism of the unique FOXL2 mutation remains incompletely understood. To identify FOXL2C134W-dependent pharmacologic synergies, we created and characterized endogenous FOXL2 isogenic AGCT cells and an AGCT tumoroid biobank. A drug screen identified that glucocorticoids promote FOXL2C134W-dependent AGCT growth. Epigenetic investigation revealed that the Cys134Trp mutation exposes latent DNA sequence-specific pioneering activity in FOXL2, a unique oncogenic mechanism. FOXL2C134W pioneering activity redirects glucocorticoid receptor chromatin occupancy to drive hyaluronan synthase 2 gene expression and increase extracellular hyaluronan secretion. Treatment of AGCT models with hyaluronidase reduces viability and this effect can be rescued by dexamethasone. Thus, gain-of-function pioneering activity contributes to the oncogenic mechanism of FOXL2C134W and creates a potentially targetable synergy with glucocorticoid signaling.

  Study EGAS50000000622

• Changes in CRISPR/Cas9 Outcomes depending on the usage of Pifithrin-alpha

  Study of the effects of Pifithrin-alpha in the context of genetic-engineering in primary human T cells.

  Study EGAS50000000656

• The Genetic Basis of Preeclampsia in an Andean Population Adapted to High Altitude

  Study EGAS00001004625