3855 results for "*geneti*"

in 36.30 milliseconds.

• Single Cell and Spatial Transcriptomics Studies of Fibrosis in Prospective Registry in IBD Study at MGH and GI Disease and Endoscopy Registry

  Stricturing disease or fibrosis is a common complication of inflammatory bowel disease (IBD), often requiring surgical intervention. This process is caused by the abnormal deposition of extracellular matrix in the context of inflammation, and thus involves crosstalk between multiple cell types including fibroblasts and immune cells. To understand the cellular interactions involved in fibrosis, we performed single cell and spatial transcriptomic analyses of biopsy or resection samples from IBD patients, diverticulitis patients or controls.For single cell analyses, intestinal samples were processed within three hours of collection by first stripping the epithelial layer with EDTA and then enzymatically digesting the underlying tissue. Cells from both the epithelial and tissue fractions were separately loaded in two channels on a 10x Chromium controller and libraries were generated with the 3'v3 Chemistry pipeline before sequencing on an Illumina sequencer. The resulting sequence data was demultiplexed and analyzed with the CellRanger pipeline to generate raw fastq files and processed gene-count matrices for each sample.For spatial transcriptomic analyses, intestinal resection samples were snap frozen in OCT (optimal cutting temperature embedding medium). Blocks were cut into 10μm sections in a cryostat and transferred to a 10x Genomics Visium slide v1. Spatially barcoded libraries were prepared according to manufacturer's instructions and sequencing on an Illumina sequencer. The resulting sequence data was processed with the SpaceRanger pipeline to generate fastq files and processed barcode-count matrices. Using the samples deposited here, we defined 68 fine-grained cell types across the ileum and colon of control and fibrotic intestinal tissues. We show that intestinal strictures were characterized by increased immune cells - including IgG+ plasma cells and CCR7hiCD4+ T cells - and inflammatory fibroblasts. We also define the transcriptional differences associated with fibrosis, with inflammatory fibroblasts in particular showing broad changes in gene expression. Spatial transcriptomics showed that key subsets colocalize within diseased tissues and identified additional populations such as interstitial cells of Cajal and enteric neurons. Further, we mapped gene expression onto intestinal biogeography, finding that known genetic risk loci are enriched within discrete spatial modules, defined by the presence of inflammatory fibroblasts and lymphoid follicles. Altogether, our datasets chart the key transcriptomic and cellular networks in stricturing CD and highlight the spatial organization of multicellular genetic risk factors.

  Study phs003943

• Sequencing of 3D Organoids Derived From Colorectal Cancer Patients

  This study focuses on the whole-exome sequencing (WES) of patient-derived organoids (PDOs) established from colorectal cancer (CRC) tumors collected at Columbia University. CRC remains a major cause of cancer-related mortality due to its metastatic progression and resistance to therapy. To model CRC at the patient level, we generated 3D organoid cultures from primary and metastatic tumors, preserving their genetic and phenotypic characteristics. The study cohort consists of 9 CRC patients with microsatellite-stable adenocarcinomas from the ascending, transverse, and descending colon, as well as the rectum, with differentiation statuses ranging from well to moderate and moderate-poor. Notably, for one patient, we generated organoids from both the primary tumor and matched liver metastases, allowing for a comparative analysis of tumor evolution. PDOs were derived from these tumors and subjected to WES at early passage to profile somatic mutations, copy number variations, and other genomic alterations to identify mutational signatures. Mutations identified in the PDOs were cross-referenced and confirmed with mutational data from the Columbia Solid Tumor Panel, which was conducted on all tumor tissues prior to organoid establishment. Molecular technologies employed include next-generation sequencing (NGS) for WES, enabling high-resolution characterization of the genomic landscape of CRC PDOs. WES of PDOs allowed us to classify tumor samples based on oncogenic mutations and mutation types, with a specific focus on PIK3CA. Notably, the efficacy of PI3Kα-specific pharmacologic inhibitors in suppressing organoid growth was dependent on the mutational status of KRAS and PIK3CA, underscoring the importance of genomic context in therapeutic response. The dataset available through dbGaP includes raw WES data from CRC PDOs.

  Study phs003965

• Childhood Cancer Data Initiative (CCDI): Comprehensive Genomic Sequencing of Pediatric Cancer Cases (CMRI/KUCC)

  This study provides paired tumor normal genomic sequencing data from ~ 200 children with cancer, including both solid tumors and leukemias, done by the Children's Mercy Research Institute (CMRI) and University of Kansas Cancer Center (KUCC). These data include whole genome sequencing (generally, ~20x), whole exome sequencing (generally, ~300x), bulk RNA sequencing (generally, ~80 million reads), and single-cell RNA and ATAC sequencing (>50,000 reads/cell). Additional phenotypic, pathologic, and genetic data, gathered clinically for these samples, are also provided.

  Study phs002529

• Genomic Changes in Breast Cancer Among Chinese Women in Hong Kong

  Recently, tumor sequencing and profiling analyses have improved molecular classification and refined existing breast cancer subtypes. However, epidemiologic data are absent in most somatic profiling studies even in extensively studied Western populations. The expansion of genomic studies to understudied populations with the integration of etiologic factors will allow the capture of a much wider range of genetic structure and mutagenic exposures associated with breast cancer risk. We therefore conducted a detailed molecular characterization of paired breast tumor/normal tissues using fresh frozen tissues collected from breast cancer cases in an ongoing breast cancer case-control study in Hong Kong. These analyses included whole genome (WGS)/exome sequencing (WES), targeted DNA panel sequencing, RNA sequencing (RNA-Seq), and genome-wide methylation profiling analyses.

  Study phs001870

• A Comprehensive Genetic Study of Classical Hodgkin Lymphoma Using Circulating Tumour DNA

  This study on classical Hodgkin lymphoma (cHL) used advanced methods to analyse circulating tumour DNA (ctDNA) in 297 cases, offering insights into its genetic landscape and linking it to disease pathophysiology and clinical progression. Key findings include the identification of whole genome duplication as a predictor of poor chemotherapy response. Additionally, a highly recurrent somatic expression quantitative trait locus of the BCL6 gene was discovered, implicating regulatory mutations in cHL pathophysiology and highlighting BCL6 as both a vulnerability and therapeutic target. Consensus clustering identified two cHL subtypes distinguished by the underlying mechanisms of genetic instability, rather than by specific genetic mutations or EBV infection. The study also linked the number and clonality of neoantigens with tumour microenvironment and response to checkpoint blockade. Finally, our results suggested ctDNA analysis as a tool to distinguish ambiguous PET/CT-positive lesions persisting after treatment, aiming to reduce unnecessary medical interventions.

  Study EGAS50000000873

• Biopsy-Derived Organoids in Personalised Early Breast Cancer Care: Challenges of Tumour Purity and Normal Cell Overgrowth Cap Their Practical Utility

  The ability to establish organoids composed exclusively of tumour rather than healthy cells is essential for their implementation into clinical practice. Organoids have in recent years emerged as a powerful tool to expand patient material in culture and generate modifiable 3D models derived from humans or animal models. For translational research, they enable the creation of model systems for an ever-increasing number of cell types and diseases. And in personalised medicine, they potentially allow for functional drug testing with high predictive power in certain settings. We found that using biopsy material from untreated, early-stage primary breast cancer patients poses significant challenges for consistently culturing tumour cells as organoids. Specifically, we observed frequent outgrowth of genetically normal, non-cancerous epithelial cells. We analysed >100 biopsy samples from early-stage breast cancer and present our large collection of >70 organoid lines. We also show methods of assessing successful tumour cell culture in a time and cost-efficient manner, proving a high rate (>85%) of normal cell overgrowth in early-stage breast cancer organoids. Finally, we show a number of successful attempts to culture cancer organoids from mastectomy-derived tissue of advanced, metastatic breast cancer. We conclude that the usefulness of organoids from early breast cancer for translational research and personalised medicine, especially guidance of adjuvant or post-surgical maintenance therapy, is strongly limited by the low success rate of culturing cancerous cells under organoid conditions.

  Study EGAS50000000605

• The genomic basis of childhood T-lineage acute lymphoblastic leukemia

  T-lineage acute lymphoblastic leukemia (T-ALL) is a high-risk tumor that has eluded comprehensive genomic characterization, in part due to the high frequency of non-coding genomic alterations resulting in oncogenic dysregulation. Here we report integrated genome and transcriptome sequencing of T-ALL tumor and remission samples obtained from over 1300 uniformly treated children with T-ALL, coupled with epigenomic and single cell analysis of malignant and normal T cell precursors. Integrated analysis identified 15 subtypes with distinct genomic drivers, gene expression, developmental state and outcome. Integration with chromatin topology analyses enabled elucidation of multiple mechanisms of enhancer deregulation that involve enhancers and genes in a subtype-specific fashion. We show that the immunophenotypically-described, high-risk entity of early T-cell precursor ALL is superseded by a broader category of leukemias of variable immunophenotype with diverse genomic alterations of a core set of genes encoding regulators of hematopoietic stem cell development. Numerous genetic alterations and disease subtypes emerged as independent predictors of survival and treatment failure in univariable and multivariable outcome models. These findings provide a roadmap for the classification, risk stratification and mechanistic understanding of this disease.

  Study EGAS50000000016

• Identification and targeting of extremely high-risk gamma delta T-ALL in children

  Acute lymphoblastic leukemia expressing the gamma delta T cell receptor (γδ T-ALL) is an uncommon, poorly understood disease. We studied 200 pediatric γδ T-ALL enrolled on clinical trials to understand the clinical and genetic features of this disease, which showed variation in outcome according to age and genetic driver. γδ T-ALL diagnosed in children under three years of age was extremely high-risk and enriched for genetic alterations leading to both LMO2 activation and STAG2 inactivation. Using patient samples and isogenic cell lines, we show that inactivation of STAG2 profoundly perturbs chromatin organization by altering enhancer-promoter looping and results in deregulation of gene expression related to T-cell differentiation. High throughput drug screening identified a vulnerability in DNA repair pathways arising from STAG2 inactivation, which was efficaciously targeted by PARP inhibition. These data provide a diagnostic and therapeutic framework for classification and risk stratification of pediatric γδ T-ALL.

  Study EGAS50000000018

• Epigenetic memory of SARS-CoV-2 mRNA vaccination in monocyte-derived macrophages

  Immune memory is key to effective antimicrobial responses, but the impact of mRNA vaccines on this process is not fully understood. Our research shows that SARS-CoV-2 mRNA vaccines alter the epigenetic profile of human macrophages, specifically enhancing histone acetylation, which is linked to immune training. Significant epigenetic changes, along with increased cytokine release, require two vaccine doses. However, these effects diminish over time but can be restored with a booster dose six months later, maintaining a strong pro-inflammatory response.

  Study EGAS50000000341

• H3K27ac ChIP-seq of lung neuroendocrine tumors

  H3K27ac ChIP-seq of lung neuroendocrine tumors

  Study EGAS50000000057