3288 results for "ovarian cancer"

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• National Cancer Institute - Population Structure and Natural Selection in the Epidemiology of Burkitt Lymphoma in East African Children and Minors (EMBLEM) study in Uganda

  A genome-wide analysis of genetic structure, gene flow, and natural selection was conducted in populations in the endemic Burkitt lymphoma (eBL) belt in Ghana and Northern Uganda, both subject to a high incidence of falciparum malaria and eBL. These populations have different ethnolinguistic ancestries and are located 2400 miles apart in sub-Saharan Africa. We characterized genetic composition of these populations in the context of 22 additional African populations and present evidence for gene flow events that occurred in the last 3000 years, possibly related to regional migrations in Western Africa and major migrations involving Nilotic, Cushitic, and Bantu groups. The Ugandan population was comprised of 758 children (mean age ~7 years) from 17 Western Nilo-Saharan tribes. The current dataset includes 561 healthy children and 197 children with eBL from northern Uganda.

  Study phs001705

• Childhood Cancer Data Initiative (CCDI): Identification and Targeting of Treatment Resistant Progenitor Populations in T-cell Acute Lymphoblastic Leukemia

  Our goal with this study was to identify the mechanisms of treatment resistance in T-cell acute lymphoblastic leukemia (ALL) using single-cell genomics. We profiled 40 T-ALL cases from the Children's Oncology Group AALL0434 clinical trial using CITE-seq/snATAC-seq, capturing a breadth of immunophenotypes, including early T-cell precursor (ETP) and near-ETP/non-ETP subtypes. By integrating analyses of T-ALL cells with the normal T-cell developmental trajectory, the study identified a specific subgroup of leukemia cells resembling bone marrow progenitors (BMP-like cells). These BMP-like cells were associated with treatment failure and poor overall survival in T-ALL patients. Overall, this study reveals comprehensive multiomic signatures for rapidly assessing risk and tailoring targeted treatment for high-risk T-ALL patients.

  Study phs003432

• Childhood Cancer Data Initiative (CCDI): Pediatric In Vivo Testing Program - Neuroblastoma

  The goal of NCI's Pediatric In Vivo Testing Consortium (PIVOT) is to advance the development of effective treatments for pediatric cancers through preclinical in vivo testing of novel therapeutic agents. To design impactful experiments that can be rapidly translated to the clinic, PIVOT investigators require comprehensive genomic characterization of the patient-derived xenograft (PDX) models used across the consortium. This robust experimental design enhances collaboration with industry partners by providing proof-of-concept data for drugs in development. As part of this effort, neuroblastoma PDX models are being molecularly characterized to identify promising therapeutic candidates. The molecular profiling includes whole exome sequencing (WES), RNA-seq, MethylEPIC array, CytoSNP array, and DNA fingerprinting for quality control. Additionally, demographic and clinical data (e.g., diagnosis, disease site, disease status) are shared. These characterized PDX models, matched with patient tumors, guide model selection for preclinical drug testing.

  Study phs003163

• Immediate Postoperative Minimal Residual Disease Detection with MAESTRO Predicts Recurrence and Survival in Head and Neck Cancer Patients Treated with Surgery

  We selected 24 patients with locally advanced head and neck squamous cell carcinoma (HNSCC) who were surgically treated. MAESTRO, our ultrasensitive, tumor-informed, mutation enrichment sequencing assay, was applied in a pooled format (MAESTRO-Pool) to plasma samples collected from these patients at baseline (pre-op) and postoperatively. We show that detection of circulating tumor DNA (ctDNA) 1 to 9 days after surgery is associated with significantly worse survival. Many plasma samples also had tumor fractions detected below 100 parts-per-million, the detection limit for first-generation commercial assays, highlighting the need for more sensitive ctDNA assays. Here we provide whole genome sequencing of matched tumor biopsy and normal germline DNA from 24 patients that were used to identify somatic single nucleotide variants (SNVs) to be tracked using our MAESTRO-Pool assay.

  Study phs003981

• Dynamic Evolution of Fibroblasts Revealed by Single Cell RNA Sequencing of Human Pancreatic Cancer

  Understanding the constituents of the pancreatic ductal adenocarcinoma (PDAC) microenvironment may illuminate more efficacious targets for treating this aggressive malignancy. However, the compositional changes occurring in untreated and treated PDAC relative to both normal and inflamed pancreas have not been well characterized. To provide a more comprehensive understanding of the PDAC tumor microenvironment relative to the non-cancerous pancreas, we performed single-cell expression profiling (10X Genomics Chromium) on samples of upfront resectable PDAC, FOLFIRINOX-based treated PDAC, chronic pancreatitis, and normal pancreas specimens from 19 patients. Spatial gene expression profiling (10X Genomics Visium) was performed to gain additional insight into cell populations. Our analysis revealed that fibroblasts are central mediators of cell-cell communication in both inflamed and malignant settings and defined unique roles for these cell populations in different disease contexts.

  Study phs003751

• Sequence data to study genomic CNVs that drive apoptotic resistance and relapses on immune checkpoint inhibitors

  This project investigates the genomic mechanisms underlying acquired resistance to immune checkpoint inhibitors (ICIs) across tumor types, addressing the critical clinical problem of treatment relapses where the molecular basis remains poorly understood. Through integrative genomic analyses of longitudinal clinical melanomas, functional CRISPR-Cas9 screens, and human and murine melanoma models, the study demonstrates that copy-number variant (CNV)-driven subclonal evolution is a primary driver of clinical relapses. The research identifies resistance-driver genes targeted by CNVs, including pro-apoptotic gene deletions and anti-apoptotic gene amplifications, which collectively downregulate apoptotic priming in resistant cells. The findings establish that modulating the apoptotic threshold can prevent or reverse ICI resistance, positioning CNV evolution as a key driver of acquired resistance and identifying apoptotic regulation as a therapeutic target to combat resistance evolution.

  Study EGAS50000001055

• H3K27ac ChIP-seq in TMPRSS2:ERG positive and negative prostate cancer tissue samples

  The TMPRSS2:ERG (T2E) structural rearrangements typifies ~50% of prostate tumors and results in overexpression of the ERG transcription factor. Using chromatin data collected in T2E and non-T2E primary prostate tumors, we show a distinct cis-regulatory landscape between T2E and non-T2E, inclusive of Cluster Of Regulatory Elements (COREs). This is mediated by ERG co-option of HOXB13 and FOXA1 implementing a T2E-specific transcriptional profile. We also report a T2E-specific CORE on the structurally rearranged ERG locus arising from spreading of the TMPRSS2 locus pre-existing CORE, assisting in its overexpression. Finally, we show that the T2E-specific cis-regulatory landscape reveals a vulnerability against the NOTCH pathway. Taken together, our work shows that overexpressed ERG co-opts master transcription factors to deploy a unique cis-regulatory landscape inducing a druggable dependency on NOTCH signaling in T2E prostate tumors.

  Study EGAS00001002496

• Investigation_of_mutational_signatures_associated_with_DNMT3A_deficiency_

  Mutational signatures have been shown to be attributable to specific genetic contexts, such as mutations in DNA repair genes. DNMT3A is a DNA methyltransferase that helps maintain the DNA methylation pattern in a site-specific manner and may participate in DNA repair or the stress response. We have identified an adult individual who is a germline mosaic for a DNMT3A mutation. We have obtained clonal lymphoblastoid cells (LCLs) from the subject representing both WT and mutant lines grown in the same individual for >50 years. These clones represent a unique opportunity to examine the mutational impact of the DNMT3A mutation in a well-controlled setting. Our goal is to perform WGS on whole blood, representing the pool, as well as several WT and several mutant clones, in order to investigate the contribution of DNMT3A to mutation rates and signatures.

  Study EGAS00001002329

• Sequencing of pancreatic cancer primary tumors and metastases

  The extent of heterogeneity of driver gene mutations present in naturally occurring metastases is largely unknown, i.e. treatment-naïve metastatic disease. To address this issue, 60x whole genome sequencing of 26 metastases from 4 patients was carried out. We found that the identical driver gene mutations were present in every metastatic lesion of each patient studied. Passenger gene mutations not known or predicted to have functional consequences accounted for all intratumoral heterogeneity. Even with respect to these passenger gene mutations, the genetic similarity among the founding cells of metastases was markedly higher than that expected for any two cells randomly taken from a normal tissue. The uniformity of driver gene mutations among metastases in the same patient has critical, encouraging implications for the success of future targeted therapies in advanced stage disease.

  Study EGAS00001002186

• CRLF2_sequencing_project_

  I hope to gain insight into novel genetic aberrations present in these patients that will highlightimportant pathways that are involved in this subtype of leukaemia. It would be interesting to see ifthe mutations and pathways that are activated are consistent between the patients, or differencesare observed dependent upon whether the patient has the translocation or the PAR1 deletion. Ofnote is the high association with either numerical gains of chromosome X or numerical/structuralabnormalities of chromosome 21 (Down syndrome, iAMP21) in patients with CRLF2 deregulation. Ihope to find abnormalities linking chromosomes X and 21 to CRLF2 deregulation in BCP‐ALL. Byincluding the three patients that are normal for CRLF2, but have consistent genetic abnormalitiesfound in the experimental cohort, I expect to find genetic differences between these two groupsthat will help us to identify novel molecular targets specific to CRLF2 deregulation.

  Study EGAS00001000080