13380 results for ""60+mice"+"6+weeks"+diet+study+2014+2017+DOI"

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• Linked-Read Whole Genome Sequencing Profiles Structural Variant Landscape of Gliomas with Barcode-Level Evidence

  Structural variants (SVs) play essential roles in glioma oncogenesis and offer prognostic insights, yet the SV landscape of gliomas has not been completely characterized due to previous technological limitations. To comprehensively profile the SV landscape of gliomas, we performed linked-read whole genome sequencing (LR-WGS) on 31 tumour samples from 20 glioma patients. Using barcode-level evidence, we validated known SVs and identified the presence of extrachromosomal DNA containing the EGFR sequence, which correlates with elevated EGFR expression. Additionally, we uncovered rare SVs affecting genes typically mutated by single nucleotide variants (SNVs), including those in the SWI/SNF chromatin remodeling complex. Our analysis also reveals selective chromosomal vulnerabilities to SVs, highlighting certain chromosomes as hotspots for SV accumulation. Collectively, our results demonstrate the utility of LR-WGS in accurately detecting SVs and thoroughly profiling SV landscapes using barcode-level evidence. The insights gained into the synergistic effects of SNVs and SVs on oncogenes further underscore the importance of integrating SV analysis when examining mutations in gliomas.

  Study EGAS50000000947

• Genome-wide analyses of cell-free DNA for therapeutic monitoring of patients with pancreatic cancer

  Determining response to therapy for patients with pancreatic cancer can be challenging. We evaluated methods for assessing therapeutic response using cell-free DNA (cfDNA) in plasma samples from 40 patients with metastatic pancreatic cancer as part of the CheckPAC trial (NCT02866383). Patients were evaluated before and after initiation of therapy using tumor-informed plasma whole-genome sequencing (WGMAF), and genome-wide cfDNA fragmentation profiles and repeat landscapes (ARTEMIS-DELFI). Of those assessed with WGMAF, molecular responders had a median overall survival (OS) of 319 days compared to 126 days for non-responders (HR=0.29, 95% CI=0.11–0.79, p=0.011). For ARTEMIS-DELFI, patients with low scores after therapy initiation had a longer median OS than patients with high scores (233 days versus 172 days, HR=0.12, 95% CI=0.046-0.31, p<0.0001). We validated ARTEMIS-DELFI in a separate cohort of 40 patients with pancreatic cancer who were part of the PACTO trial (NCT02767557). These analyses suggest that non-invasive mutation and fragmentation-based cfDNA approaches can identify therapeutic response of individuals with pancreatic cancer.

  Study EGAS50000000923

• dbGaP Collection: NIH Autism -omics Studies

  Autism Spectrum Disorders (ASD) are early onset neurodevelopmental syndromes characterized by impairments in reciprocal social interaction and communication, accompanied by restricted and repetitive behaviors. ASDs afflict ~1% of the human population, and represent a major public health burden. Evidence for the etiology of ASD has consistently pointed to a strong genetic component, though the genetic architecture is indisputably complex. This dbGaP Collection consists of studies that include GWAS, sequencing (targeted, exome, whole genome), transcriptomics, etc, across many different cohorts. Many of the datasets have been curated and harmonized with NDAR prior to submission to dbGaP. Researchers who request and are approved to access this collection will be granted access to all related substudies in dbGaP as well as all NDAR data. Individual level genomics data will only be available for download through dbGaP along with minimal phenotype and pedigree information. Detailed phenotype and available imaging data related to these same research subjects are available for query and download within NDAR. The NDAR GUID will allow individual genomic data to be associated with all NDAR data collected for those subjects.

  Study phs000764

• Ancient tree-topologies and gene-flow processes among human lineages in Africa

  The deep history of human evolution in Africa remain intensely debated. We produced 73 novel high-quality whole genomes from 14 Central and Southern African populations with diverse cultural practices. With extensive simulations and machine-learning Approximate Bayesian Computation inferences, we reconstruct jointly their complex history of divergences and migrations. We find vast genome-wide diversity within and among populations, often uncorrelated with geography and cultural practices. This demonstrates the necessity to explicitly consider local genomic patterns, without merging samples indiscriminately into larger a priori categories, to reconstruct human evolutionary histories. We find that tree-like evolutions with long periods of drift between short periods of unidirectional gene-flow best explain the data, and that the lineage ancestral to Khoe-San populations diverged around 300,000 years ago from a lineage ancestral to rainforest hunter-gatherers and neighboring agriculturalists. We also find that short periods of ancient and recent gene-flow coincide with epochs of major ecological and cultural changes in Sub-Saharan Africa.

  Study EGAS50000001072

• Aberrant Oligoclonal Hematopoiesis in Remission AML and Relapse from Rare Cells Genomically Resembling Leukemic Blasts

  Acute myelogenous leukemia (AML) is a hematological malignancy that often responds well to initial treatment in which patients achieve a complete remission (CR). Nevertheless, most patients will relapse after achieving a CR, which is often fatal. This minimal residual disease (MRD) that remains after CR is likely the source of relapse and so improved measurement and characterization of these residual cells is critical. Employing droplet digital PCR (ddPCR), we were able to measure mutated alleles of many recurrently mutated genes in bone marrow samples acquired during CR from AML patients at levels as low as 0.002% variant allele frequency. Most of these gene mutations persisted in CR but at very variable and gene-dependent levels. Most AML cases involved residual aberrant oligoclonal hematopoiesis, and rare cell populations (as few as 1 in 15,000) were detected that were genomically similar to the AML blast populations at that dominated at diagnosis and were fully clonally represented at relapse. From a clinical perspective, the mutant allele frequency correlated closely with relapse-free and overall survival.

  Study phs001408

• KAT6A and KAT7 Histone Acetyltransferase Complexes Are Molecular Dependencies and Therapeutic Targets in NUP98-Rearranged Acute Myeloid Leukemia

  NUP98 fusion oncoproteins (FOs) are a hallmark of childhood acute myeloid leukemia (AML). NUP98 FOs drive leukemogenesis through phase-separated condensate formation and maintenance of an active chromatin landscape at stem cell-associated genes in cooperation with epigenetic regulators. Here we show that MYST family histone acetyltransferase (HAT) complex proteins including KAT6A/MOZ, KAT7/HBO1, and the common KAT6A/7 complex subunit BRPF1 associate with NUP98 FOs on chromatin and within condensates. MYST HATs are molecular dependencies in NUP98-rearranged (NUP98-r) leukemia, and genetic inactivation or pharmacologic inhibition of Kat6a and Kat7 impairs NUP98-r cell fitness. KAT6A/7 inhibition decreased global H3K23ac levels, displaced NUP98::HOXA9 from chromatin at the Meis1 locus, and led to myeloid cell differentiation. Additionally, KAT6A/7 inhibition decreased leukemic burden in multiple NUP98-r leukemia xenograft mouse models, synergized with Menin inhibitor treatment, and was efficacious in Menin inhibitor-resistant cells. In summary, we show that MYST family HATs are therapeutically actionable dependencies in NUP98-r AML.

  Study EGAS50000001075

• Anti-TIGIT antibody tiragolumab improves PD-L1 blockade via myeloid and Treg cells

  Tiragolumab, an anti-TIGIT antibody with an active IgG1/kappa Fc, demonstrated improved outcomes in the phase 2 CITYSCAPE trial (NCT03563716) when combined with atezolizumab (anti-PD-L1) versus atezolizumab alone1. However, there remains little consensus on the mechanism(s) of response with this combination2. We found that high baseline intratumoral macrophages and Tregs were associated with better outcomes in patients treated with atezolizumab plus tiragolumab but not with atezolizumab alone. Serum sample analysis revealed that macrophage activation was associated with clinical benefit in patients receiving the combination treatment. In mouse tumor models, tiragolumab surrogate antibodies inflamed tumor-associated macrophages, monocytes, and dendritic cells through Fc gamma receptors (FcɣR), in turn driving anti-tumor CD8+ T cells from an exhausted effector-like state to a more memory-like one. These results uncover a mechanism of action by which TIGIT checkpoint inhibitors can remodel immunosuppressive tumor microenvironments, and suggest that FcɣR engagement is an important consideration in anti-TIGIT antibody development.

  Study EGAS50000000251

• Shifted assembly and function of mSWI/SNF family subcomplexes underlie targetable dependencies in endometriod carcinomas

  The mammalian SWI/SNF (mSWI/SNF) family of chromatin remodelers govern cell type-specific chromatin accessibility and gene expression and assemble as three distinct complexes: canonical BAF (cBAF), Polybromo-associated BAF (PBAF), and non-canonical BAF (ncBAF). ARID1A and ARID1B are paralog subunits that specifically nucleate the assembly of cBAF complexes and are frequently dual deleted in highly aggressive differentiated endometrial carcinomas (DECs). Here, in cellular models and primary human tumors, we find that ARID1A/B-mediated cBAF loss results in increased ncBAF and PBAF biochemical abundance and function genome-wide to maintain the DEC oncogenic signature. Further, treatment of ARID1A/1B-mutant cell lines and PDX models in vivo with a clinical-grade SMARCA4/2 ATPase inhibitor, FHD-286, markedly attenuates cell proliferation and tumor growth, and synergizes with carboplatin-based chemotherapy. Taken together, these findings reveal the oncogenic contributions of shifted of mSWI/SNF family complex abundance and chromatin-level gene regulatory functions and suggest therapeutic utility of mSWI/SNF complex small molecule inhibitors in dedifferentiated endometrial carcinoma and other cBAF-disrupted cancer types.

  Study EGAS50000001004

• Chromatin accessibility in stem cells unveils progressive transcriptional reprogramming in myelodysplastic syndrome

  Myelodysplastic syndromes (MDS) originate from hematopoietic stem cell (HSC) clones with acquired gene mutations/deletions. However, our knowledge on the epigenetic properties of MDS stem cells are limited. Here, we examined chromatin accessibility of MDS stem cells. Chromatin accessibility profiles of MDS stem cells represented the disease status better than progenitor cells and unveiled the process of stem cell reprograming during disease progression. Characterization of differentially accessible regions (DARs) revealed that MDS stem cells acquire progenitor-like chromatin accessibility with disease progression, resulting in imprecise stem-progenitor hierarchy. Profiling of transcriptional factor binding motifs at DARs revealed precocious inactivation and activation of HSC and myeloid transcriptional networks, respectively, in MDS stem cells. Increased chromatin accessibility at CEBP target sites well represented the myeloid reprograming of MDS stem cells and stratified MDS into distinct subgroups. Newly developed "Progenitor scores" based on chromatin accessibility well stratified the disease status and correlated with prognosis. These results highlight that the chromatin properties of MDS stem cells define the cell-autonomous behavior of MDS and disease progression.

  Study JGAS000718

• Single Cell RNA-Sequencing of BCG Naive and Recurrent Non-Muscle Invasive Bladder Cancer Reveals a CD6/ALCAM-Mediated Immune-Suppressive Pathway

  Non-muscle invasive bladder cancer (NMIBC) represents 70&#8211;80% patients with newly diagnosed bladder cancer, and Bacillus Calmette-Guerin (BCG) remains a cornerstone treatment for intermediate- and high-risk NMIBC to prevent disease recurrence and progression. However, a significant number of patients experience recurrence after their first course of BCG, posing significant challenges in the management of the disease. We conducted single cell RNA sequencing (scRNA-Seq) on freshly collected NMIBC samples, distinguishing between those naive to BCG treatment and those that recurred post-BCG treatment. We observed a clear activation of inflammatory pathways across cell types during recurrence, but these were not associated with canonical immune checkpoint or T cell exhaustion phenotypes. Analysis of cell-to-cell communication revealed enhanced interactions between T cells and urothelial cells in BCG-recurrence, predominantly modulated by CD6 and activated leukocyte cell adhesion molecule (ALCAM). Furthermore, we found CD6hi T cells to be immunosuppressed and enriched in recurrent samples, suggesting a potential role for CD6 as an immune evasion signal in NMIBC.

  Study phs003742