14658 results for "PLOS+ONE+Pennsylvania+German+ACS+language+code+pdc+open+access+study"

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• Parent-of-origin dependent DNA methylation and gene expression in the human placenta

  DNA methylation is globally reprogrammed after fertilization and the parental genomes have similar DNA methylation profiles after implantation except at the germline differentially methylated regions (gDMRs). We, and others, have previously shown that there are a large number of transient gDMRs in human blastocysts, whose differential methylation is lost in embryonic tissues after implantation. In this study we employed genome-wide allelic DNA methylation analyses of highly purified trophoblast cells from human placentas. ~40% of the transient-in-embryo gDMRs maintained their parent-of-origin-dependent biased allelic methylation. RNA sequencing-based allelic expression analyses revealed that some of the placental-specific gDMRs were associated with novel imprinted genes. This approach identified the first examples of X-linked gDMRs specific to the placenta. These findings highlight the unique regulation of allelic DNA methylation in the human placenta, which is important for understanding normal placental development and the pathogenesis of pregnancy complications.

  Study JGAS000038

• Loss of presentation of estimated neoantigens from mutated genes in ctDNA was essential for fostering primary to recurrent tumors in postoperative colorectal cancer cases

  Specific parameters regarding mutations at primary sites for the detection of postoperative recurrence using circulating tumor (ct)DNA liquid biopsy are lacking. In the current retrospective study, we conducted target resequencing of ctDNA using 47 plasma samples and established a cancer panel carrying the commonly mutated genes between primary and recurrent tumors. We found that mutated genes in ctDNA indicated immune-resistance traits with respect to the impaired ability to present neoantigens by loss of expression or binding affinity to HLA in the primary tumor. Compared with the estimated neoantigens from all mutated genes in primary tumors, the neoantigen peptides from commonly mutated genes between primary and recurrent tumors showed abundant and significant expression with no binding affinity to HLA. Therefore, ctDNA mutations can be frequently and postoperatively detected to identify recurrence; however, these mutated genes were derived from immune-tolerated clones owing to the loss of neoantigen presentation in primary CRC tumors.

  Study JGAS000549

• T cell receptor repertoire in cell-free DNA as a proxy for tumor infiltrates in patients treated with pembrolizumab

  Profiling tumour and systemic T-cell receptor (TCR) repertoires can identify features associated with clinical benefit of cancer patients on immune checkpoint blockade therapy. This study reports on diversity and specificity analysis of TCR sequences from 59 tumor, 306 peripheral blood (PBMC), and 73 cell-free DNA (cfDNA) samples from 81 patients with solid tumors treated with pembrolizumab. This analysis reveals that head and neck carcinomas have significantly lower PBMC diversity and shorter persistence of pembrolizumab-induced diversification compared to other cancers. Using GLIPHII (Grouping Lymphocyte Interactions with Paratope Hotspots), we find that tumor-derived clonotypes form non-microbial specificity signatures that are shared across patients and cancer types. Tumor-derived clonotypes are enriched in cfDNA compared to PBMCs, despite the diversity of cfDNA TCR repertories being two orders of magnitude lower than PBMCs. TCRs shared between tumors and cfDNAs persist in PBMCs beyond 50 weeks of treatment, suggesting cfDNA captures clonotypes contributing to anti-tumor immune surveillance.

  Study EGAS50000001306

• Single Cell RNA Transcriptomics of Mantle Cell Lymphoma Reveals the Presence of Treatment-Resistant Subclones at the Time of Diagnosis

  Mantle cell lymphoma is a chronically relapsing B cell neoplasm characterized by clonal heterogeneity. We implemented single cell RNA sequencing of paired tumor samples from four patients with an aggressive nodal MCL at diagnosis and after failure of standard immunochemotherapy. Clustering the cells based on the inferred CNVs showed small subclones present at diagnosis with a CNV profile similar to the major subclone at relapse. Comparison of these subclones to major subclones present at diagnosis revealed 119 upregulated pathways common for the four patient with an aggressive MCL, including NF-kappaB and PTEN signaling pathways. Additionally, we sequenced a patient with an indolent to blastoid MCL transformation with intestinal tissue involvement. In contrast to other compartments at relapse, the cells in the intestine showed strikingly different CNV profile and presence of new driver mutations including NOTCH1. In conclusion, our study demonstrates that scRNAseq can potentially detect therapy resistant subclones at diagnosis.

  Study EGAS50000000825

• Measles oncolytic virus as an immunotherapy for recurrent/refractory pediatric medulloblastoma and atypical teratoid rhabdoid tumor

  Pediatric recurrent medulloblastoma (MB) and atypical teratoid rhabdoid tumor (ATRT) are largely incurable and warrant novel therapies. We investigated a) the safety of a measles virus variant, MV-NIS, in a pediatric phase 1 study and b) the mechanisms of MV-NIS and potential benefit of combination with immune checkpoint inhibition (ICI). Pediatric patients with recurrent MB or ATRT were treated with intratumoral injections for local recurrence or via lumbar puncture for disseminated recurrence. We evaluated local immune responses to MV-NIS with and without ICI via single-cell and bulk RNA sequencing in an intracranial, immunocompetent, syngeneic murine model. MV-NIS given intratumorally or via repeat intrathecal dosing was safe. MV-NIS prolonged survival in murine models but did not demonstrate additive benefit with ICI. No changes in tumor-infiltrating immune-cell composition or activation were observed in response to MV-NIS treatment; however, MV-NIS induced local expression of neutralizing antibodies, complement cascade, and phagocytosis-related genes.

  Study EGAS50000000811

• Adjuvant nivolumab in resected esophageal or gastroesophageal junction cancer: exploratory biomarker analyses from CheckMate 577

  Adjuvant nivolumab demonstrated a significant improvement in disease-free survival (DFS; primary endpoint) versus placebo in patients with resected esophageal or gastroesophageal junction cancer and residual pathologic disease following neoadjuvant chemoradiotherapy (CRT) in the phase III CheckMate 577 study, leading to global approval and widespread adoption. Exploratory biomarker analyses were performed using whole-exome sequencing, RNA sequencing, and immunohistochemistry. Hazard ratios for DFS favored nivolumab versus placebo in patients with higher inflammation and proliferation gene expression signature scores; lower M2 macrophage, endothelial, and stromal GES scores; and higher densities of CD3+/CD8- T cells and natural killer cells. Assessments of pre-CRT and post-CRT tumor tissue found post-CRT increases in programmed death ligand 1 combined positive score in 51% of patients, which appeared to be associated with greater DFS benefit. Through these analyses, we identified patient subpopulations that appear to derive improved DFS benefit from adjuvant nivolumab in this setting.

  Study EGAS50000001663

• Spatial genomic heterogeneity in multiple myeloma revealed by multi- region sequencing

  The bone-marrow (BM) containing skeletal system is the reservoir of Multiple Myeloma (MM), the malignant counterpart of antibody-secreting plasma cells. To gain insight into its spatial clonal architecture, we performed multi-region whole-exome sequencing of radiology-guided fine-needle aspirates from 51 MM patients. We found spatial genomic heterogeneity in a substantial proportion of cases including bi-allelic inactivation of tumor suppressors and mutations affecting cancer genes. The amount of heterogeneous mutations associated with the size of focal tumor lesions in whole body imaging consistent with focal outgrowth of highly advanced clones. In conclusion, our results support the regional initiation of transformation processes leading to high-risk disease as well as the pre-existence of key driver events in restricted areas. As such, our study does not only provide new insights in the underlying biology of MM progression but also has considerable implications for standard diagnostic approaches in the clinic.

  Study EGAS00001002111

• APCDR Uganda GWAS: Genome-wide sequence variation and susceptibility loci for cardiometabolic traits in a sub-Saharan African population (UG2G component)

  Genomic studies in African populations provide unique opportunities to understand disease aetiology, human genetic diversity and population history in a regional and a global context. To leverage the relative benefits of different strategies, we undertook a combined approach of genotyping and whole-genome sequencing (WGS) in a population-based study of 6,400 individuals from a geographically defined rural community in South-West Uganda. We present data from 4,778 individuals with genotypes for ~2.2 million SNPs from the Uganda GWAS resource (UGWAS), and sequence data on up to 1,978 individuals spanning 41.5M SNPs and 4.5M indels (UG2G); 343 individuals overlap between the two datasets. We highlight the value of the largest sequence panel from Africa to date as a global resource for variant discovery, imputation and understanding the mutational spectrum and its clinical relevance in African populations. Alongside phenotype data, we provide a rich new genomic resource for researchers in Africa and globally.

  Study EGAS00001000545

• Frequent alterations in cytoskeleton remodeling genes in primary and metastatic Chinese lung adenocarcinomas

  The landscape of genetic alterations in lung adenocarcinoma derived from Asian patients is largely uncharacterized. Here we present an integrated genomic and transcriptomic analysis of 335 primary lung adenocarcinomas and 35 corresponding lymph node metastases from Chinese patients. Altogether 13 significantly mutated genes are identified, including themost commonly mutated gene TP53 and novel mutation targets such as RHPN2, GLI3 and MRC2. TP53 mutations are furthermore significantly enriched in tumours from patients harbouring metastases. Genes regulating cytoskeleton remodelling processes are also frequently altered, especially in metastatic samples, of which the high expression level of IQGAP3 is identified as a marker for poor prognosis. Our study represents the first large-scalesequencing effort on lung adenocarcinoma in Asian patients and provides a comprehensive mutational landscape for both primary and metastatic tumours. This may thus form a basis for personalized medical care and shed light on the molecular pathogenesis of metastatic lung adenocarcinoma.

  Study EGAS00001000982

• Resequencing_candidate_genes_for_male_spermatogenic_impairment

  This study aims to identify novel candidate variants from human Y-chromosomal genes DAZ, BPY2 and CDY1 by resequencing the coding regions of these genes from male patients with spermatogenic impairment. The coding regions of the genes have been amplified by standard PCR, amplicon lengths range from 244 to 486 bp. A total of 61 amplicons were amplified for each of the 96 patients, totalling to approx. 25 kb per sample. Amplicons were quantified by gel electrophoresis and pooled in approx. equimolar concentrations per patient. For each of the 96 submitted samples, approx. 1 microgram of amplified DNA pool is provided in a total volume of 120 microlitres. The samples need to be indexed and libraries prepared for a PE250bp Illumina MiSeq run. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/

  Study EGAS00001002157