14667 results for "PLOS+ONE+Pennsylvania+German+ACS+language+code+pdc+open+access+study"

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• NextGen Consortium: Globin Gene Expression in Sickle Cell Genotype-Specific iPS Cells

  Implement an efficient, highly reproducible and 'scalable' system for the production of large numbers of sickle cell anemia-specific iPS cells (iPSC). Derive and characterize a novel, in vitro system for the production of an unlimited supply of erythroid lineage cells from the directed differentiation of 'clinical grade' transgene-free iPS cells; use this system to recapitulate erythroid-lineage ontogeny in vitro with the sequential development of primitive and definitive erythropoiesis, accompanied by the appropriate expression of stage-specific globin genes. Identify developmental gene expression profile differences between erythroid precursors that produce primarily HbF and those that produce primarily HbA or HbS. Determine the effects of the three known HbF major quantitative trait loci (QTL) on globin gene expression in disease-specific iPS cells during in vitro erythropoiesis. Search for novel HbF genetic modifiers associated with markedly elevated HbF levels found in sickle cell anemia patients naturally, or in response to hydroxyurea treatment, by examining gene expression profiles and mRNA sequence of their iPSC-derived erythroid cells. Develop and use a CRISPR-based gene editing platform to study the effect of novel HbF genetic modifiers, explore globin switching, and correct the HbS mutation in sickle iPSC lines.

  Study phs001212

• A Whole Genome Association Search for Type 2 Diabetes Genes in African Americans

  Over 2.8 million African Americans have type 2 diabetes mellitus (T2DM). This represents approximately 13% of the African American population and a significant proportion of the 21 million Americans living with diabetes. On average, an African American individual is twice as likely to have T2DM as a European American peer. Our research group has been actively involved in the study of African American diabetes genetics for over 15 years. We hypothesize that genes contributing to the development of T2DM in African Americans exist and can be located using modern molecular genetic methods. With the exception of TCF7L2(Transcription factor 7-like 2) evidence to date suggests variants that contribute T2DM risk in European-derived populations are not significant contributors to African American T2DM risk. We have performed a SNP-based Whole Genome Association (WGA) analysis on the Affymetrix 6.0 in a case control population of over 1000 African American T2DM cases and over 1000 non-diabetic controls. The DNAs have been collected from participants using uniform criteria from North Carolina and neighboring states. Genotype data will be subjected to extensive genetic analysis with the goal of defining a priority list of SNPs for genotyping in independent populations for confirmation and further detailed analysis.

  Study phs000140

• InTEAM Consortium - Alcoholic Hepatitis

  Alcoholic hepatitis (AH) is a life-threatening condition characterized by profound hepatocellular dysfunction for which targeted treatments are urgently needed. Identification of molecular drivers is hampered by the lack of suitable animal models. By performing RNA sequencing in livers from patients with different phenotypes of alcohol-related liver disease (ALD), we describe the transcriptional programs involved in disease progression. We uncovered that development of AH is characterized by the defective activity of liver-enriched transcription factors (LETFs). The PPARG predicted activation state was found increased in early forms of ALD, while AH was associated by a marked decrease in HNF4A-dependent gene expression along with a marked expression of the fetal HNF4A isoform (P2). TGFB1, a key upstream transcriptome regulator in AH, induced the use of HNF4a P2 promoter in hepatocytes, which resulted in abnormal bile acid synthesis and defective metabolic and synthetic functions. PPARG agonists partially prevented this effect. We conclude that targeting TGFB1 and epigenetic drivers that modulate HNF4A-dependent gene expression could be beneficial to improve hepatocellular function in patients with AH. The study was conducted thanks to a multicenter collaboration under the National Institute of Alcohol Abuse and Alcoholism (NIAAA)-funded consortium: Integrated Approaches for Identifying Molecular Targets in Alcoholic Hepatitis (InTEAM).

  Study phs001807

• Comparison Between qPCR and RNA-Seq Reveals Challenges of Quantifying HLA Expression

  Human leukocyte antigen (HLA) class I and HLA class II loci are essential elements of innate and acquired immunity. Their exceptional influence on disease outcome is well documented by GWAS and candidate gene studies. The impact of HLA allelic variation on human disease through allele-specific presentation of antigenic peptides to T cells has been the main focus to determine HLA effects on disease susceptibility/pathogenesis. However, HLA expression levels have also been implicated in disease, adding another dimension to the extreme diversity of HLA that impacts variability in immune responses across individuals. HLA expression levels routinely rely on quantitative PCR (qPCR). An alternative is adoption of high throughput technologies such as RNA-Seq. This provides the opportunity to quantify HLA expression in large datasets, but also allows comparison between RNA-Seq and qPCR. In this study, we analyze expression data for HLA Class I genes for a matched set of individuals (N = 96) by RNA-Seq, qPCR and cell surface expression. Samples were obtained from the Research Donor Program (NCI-Frederick). We observed a moderate correlation between RNA-Seq and qPCR. We suggest technical and biological factors that might contribute to differences in the techniques.

  Study phs003177

• Identification of Host Genetic Factors That Are Determinant for the Development of Severe Forms of COVID-19

  We conducted whole exome sequencing (WXS) on 21 cases of Multisystem Inflammatory Syndrome in Children (MIS-C) related to COVID-19 from Brazil. All patients who were hospitalized underwent serum (ELISA) and molecular (RT-PCR) testing for SARS-CoV-2, and the main clinical symptoms associated with SARS-CoV-2 infection were collected. During hospitalization, data on complications, medical interventions, and laboratory findings were also collected. Our results revealed in an unprecedented way the occurrence of several rare loss-of-function variants in the NLRP12 gene among the affected children, and three other SNVs, predicted to be highly pathogenic, were identified in the IL17RC gene. An additional nonsense variant, in the IFNA10 gene, was identified in a single patient. Through in vitro functional analysis, we unequivocally demonstrated that these mutations impact NF-kB activation. These findings are similar to those observed in NLRP12-associated systemic autoinflammatory disorders, characterized by altered innate immune response, with increased NF-κB activation and excessive production of inflammatory cytokines. To our knowledge, our study is the first to provide a plausible molecular mechanism for MIS-C involving inborn errors in NLRP12. We suggest that some patients with MIS-C may benefit from Interleukin (IL)-1 pathway blockade treatments.

  Study phs003512

• Exploring the Microbiome-Gut-Brain Axis with Respect to Psychoneurological Symptoms for Children with Solid Tumors

  The human body hosts tens of trillions of microbes, a number 10 times greater than the number of human body cells. The collection of these human-associated microbes and their genomes is called the “human microbiome”. More than 90% of these microbes live in the gastrointestinal (GI) tract, representing 500 species on average. With the development of high-throughput sequencing technology and bioinformatics tools (e.g., 16S ribosomal RNA or 16S rRNA sequencing and shotgun metagenomics analysis), recent progress has been made to elaborate the critical role that the gut microbiome plays in human health and disease. A significant disruption (dysbiosis) of the composition and function of the gut microbiome is associated with carcinogenesis, chemotherapeutic metabolism, and treatment-related symptom toxicities. The current state of science on the gut microbiome in cancer has only recently started in animal models and adults, and has not been well investigated in children diagnosed and treated for cancer, nor with respect to associations with cancer treatment-related toxicities. This proposed study will explore the hypothesis that dysbiosis of the gut microbiome is associated with cancer treatment-related GI and psychoneurological symptoms. We will collect both stool samples (for the gut microbiome) and patient-reported outcomes across chemotherapy.

  Study phs002960

• Early Detection of Malignant and Pre-Malignant Peripheral Nerve Tumors Using Cell-Free DNA Fragmentomics

  Early detection of neurofibromatosis type 1 (NF1) associated peripheral nerve sheath tumors (PNST) informs clinical decision-making, potentially averting deadly outcomes. Here, we describe a cell-free DNA (cfDNA) fragmentomic approach which distinguishes non-malignant, pre-malignant and malignant forms of NF1 PNST. Using plasma samples from a novel cohort of 101 NF1 patients and 21 healthy controls, we validated that our previous cfDNA copy number alteration (CNA)-based approach identifies malignant peripheral nerve sheath tumor (MPNST) but cannot distinguish among benign and premalignant states. We therefore investigated the ability of fragment-based cfDNA features to differentiate NF1-associated tumors including binned genome-wide fragment length ratios, end motif analysis, and non-negative matrix factorization deconvolution of fragment lengths. Fragmentomic methods were able to differentiate pre-malignant states including atypical neurofibromas (AN). Fragmentomics also adjudicated AN cases suspicious for MPNST, correctly diagnosing samples noninvasively, which could have informed clinical management. Overall, this study pioneers the early detection of malignant and premalignant peripheral nerve sheath tumors in NF1 patients using plasma cfDNA fragmentomics. In addition to screening applications, this novel approach distinguishes atypical neurofibromas from benign plexiform neurofibromas and malignant peripheral nerve sheath tumors, enabling more precise clinical diagnosis and management.

  Study phs003712

• Pre-Existing Skin-Resident CD8 and γδ T Cell Circuits Mediate Immune Response in Merkel Cell Carcinoma and Predict Immunotherapy Efficacy

  Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer with a ~50% response rate to immunotherapy. Here, we attempted to identify novel predictive biomarkers of response through extensive and deep multi-omics interrogation of 186 samples from 116 patients. We collectively integrated bulk RNAseq, single-cell RNAseq, multiplex immunofluorescence, and spatial transcriptomics. Importantly, we were also able to study 14 matched pairs of tissue samples from pre- and post-immunotherapy. In non-responders, tumors show evidence of increased tumor cell cycling, expression of neuronal stem cell markers, and IL-1α/β. Responders have evidence of increased type I/II interferon signatures and evidence of pre-existing tissue resident (Trm) CD8 or Vδ1 γδ T cells that functionally converge with overlapping antigen-specific transcriptional programs and clonal expansion of multiple T cell receptors. Spatial transcriptomics demonstrated higher co-localization of T cells with B and dendritic cells in responders, with evidence of expression of chemokines important for co-stimulation. Finally, immunotherapy increased clonal expansion or recruitment of Trm and Vδ1 cells in tumors in responders, further underscoring their therapeutic importance. These data identify potential novel actionable biomarkers and therapeutic targets for MCC.

  Study phs003629

• Reconstructing oral cavity tumor evolution through brush biopsy

  Oral potentially malignant disorders (OPMDs) with genomic alterations have a heightened risk of evolving into oral squamous cell carcinoma (OSCC). Currently, genomic data are typically obtained through invasive tissue biopsy. However, brush biopsy is a non-invasive method that has been utilized for identifying dysplastic cells in OPMD but its effectiveness in reflecting the genomic landscape of OPMDs remains uncertain. This pilot study investigates the potential of brush biopsy samples in accurately reconstructing the genomic profile and tumor evolution in a patient with both OPMD and OSCC. We analyzed single nucleotide variants (SNVs), copy number aberrations (CNAs), and subclonal architectures in paired tissue and brush biopsy samples. The results showed that brush biopsy effectively captured 90% of SNVs and had similar CNA profiles as those seen in its paired tissue biopsies in all lesions. It was specific, as normal buccal mucosa did not share these genomic alterations. Interestingly, brush biopsy revealed shared SNVs and CNAs between the distinct OPMD and OSCC lesions from the same patient, indicating a common ancestral origin. Subclonal reconstruction confirmed this shared ancestry, followed by divergent evolution of the lesions. These findings highlight the potential of brush biopsies in accurately representing the genomic profile of OPL and OSCC, proving insight into reconstructing tumor evolution.

  Study EGAS50000000602

• Full characterization of structural variation

  Structural variants (SVs) are important contributors to human disease. Their characterization remains however difficult due to their size and association with repetitive regions. Long-read sequencing (LRS) and optical genome mapping (OGM) can aid as their molecules span multiple kilobases and capture SVs in full. In this study, we selected six individuals who presented with unresolved SVs. We applied LRS onto all individuals and OGM to a subset of three complex cases. LRS detected and fully resolved the interrogated SV in all samples. This enabled a precise molecular diagnosis in two individuals. Overall, LRS identified 100% of the junctions at single-basepair level, providing valuable insights into their formation mechanisms without need for additional data sources. Application of OGM added straightforward variant phasing, aiding in the unravelment of complex rearrangements. These results highlight the potential of LRS and OGM as follow-up molecular tests for complete SV characterization. We show that they can assess clinically relevant structural variation at unprecedented resolution. Additionally, they detect (complex) cryptic rearrangements missed by conventional methods. This ultimately leads to an increased diagnostic yield, emphasizing their added benefit in a diagnostic setting. To aid their rapid adoption, we provide detailed laboratory and bioinformatics workflows in this manuscript.

  Study EGAS50000000520