14676 results for "PLOS+ONE+Pennsylvania+German+ACS+language+code+pdc+open+access+study"

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• The Genetic Evolution of Acral Melanoma

  Acral melanoma is a rare melanoma subtype arising on the sole, palm, or nail apparatus. We performed whole-exome sequencing (WES) for a cohort of 35 acral melanoma patients. For each patient, we sequenced multiple tumor areas representing different tumor stages, including the in situ and invasive portions of the primary tumor and available regional or distant metastases. Normal areas were included for all except one patient. We identified distinct evolutional trajectory compared to melanomas arising on the sun-exposed skin. Whole-genome sequencing and targeted sequencing were additionally performed for a subset of the samples. Particularly, in acral melanomas, complex genomic aberrations, characterized by clustered copy number transitions and focal amplifications, and telomerase reverse transcriptase (TERT) activating alterations occur very early during evolution, while MAP-kinase pathway mutations, such as BRAF V600E and NRAS hotspot mutations, can occur late and often result in striking intra-tumor heterogeneity.

  Study phs003451

• Origin of second malignancies in children

  Pediatric cancers are rare diseases, and children without known germline predisposing conditions who develop a second malignancy during developmental ages are extremely rare. We present four such clinical cases and through whole-genome and error-correcting ultra-deep duplex sequencing of tumor and normal samples, we explored the origin of the second malignancy in four children, uncovering different routes of development. The exposure to cytotoxic therapies was linked to the emergence of a secondary AML. A common somatic mutation acquired early during embryonic development was the driver of two solid malignancies in another child. In two cases, the two tumors developed from completely independent clones diverging during embryogenesis. Importantly, we demonstrate that platinum-based therapies contributed at least in one order of magnitude more mutations per day of exposure than aging to normal tissues in these children.

  Study EGAS50000000167

• Single-cell RNA sequencing of 16 NPM1 mutated AML patients

  NPM1 mutated AML is the largest class in WHO classification, however several subtypes within NPM1 were already reported. Here, we sequence 16 NPM1 mutated AML samples with single-cell RNA-sequencing and multi-color flow cytometry from three major NPM1 subtypes we previously identified, totaling more than half a million cells. We show that the differences among three NPM1 subtypes are mainly driven by cell composition, and these differences are also reflected at cell surface protein level. With the re-analysis of CITE-seq data from another cohort and single cell variant calling on our data, we also report two distinct stem cell phenotypes: one with leukemic (CD34dimCD38-CD45RA+) and another with pre-leukemic (CD34+CD38-CD45RA-) origin. We believe that our data and findings provide novel insights regarding the etiology of NPM1 mutated AML.

  Study EGAS50000000332

• The Formation and Propagation of Human Robertsonian Chromosomes

  Robertsonian chromosomes are a type of variant chromosome found commonly in nature. Present in one in 800 humans, these chromosomes can underlie infertility, trisomies, and increased cancer incidence. Recognized cytogenetically for more than a century, their origins have remained mysterious. Recent advances in genomics have allowed us to assemble three human Robertsonian chromosomes completely. We identify a common breakpoint and epigenetic changes in centromeres that provide insight into the formation and propagation of common Robertsonian translocations. Further investigation of the assembled genomes of chimpanzee and bonobo highlights the structural features of the human genome that uniquely enable the specific crossover event that creates these chromosomes. Resolving the structure and epigenetic features of human Robertsonian chromosomes at a molecular level will pave the way to understanding how chromosomal structural variation occurs more generally, and how chromosomes evolve.

  Study phs003920

• A benchmark of DNA methylation deconvolution methods for tumoral fraction estimation using DecoNFlow

  In cancer patients, circulating cell-free DNA (cfDNA) originates from both healthy and cancer cells, and the proportion of tumor-derived cfDNA serves as a surrogate marker of tumor burden. Tumoral cfDNA can be identified using patient-specific mutations or more general tumor-specific DNA methylation patterns that are preserved in cfDNA, enabling non-invasive cancer detection and monitoring. Accurately estimating tumor fractions remains challenging due to the heterogeneous mixture of cfDNA sources in body fluids. Computational DNA methylation deconvolution methods can address this by estimating tumoral fraction with or without reference methylomes. Here, we benchmarked 10 reference-based and 2 reference-free DNAm deconvolution tools and provide the data generated for this benchmarking, consisting of 10 neuroblastoma cell lines and one healthy cfDNA sample (pooled from 15 healthy cfDNA samples), profiled using cfRRBS.

  Study EGAS50000001529

• An ancient DNA perspective on the Russian Conquest of Yakutia

  Yakut communities from northeastern Siberia inhabit some of the coldest environments on Earth preserving an extraordinary archaeological record. Their history was profoundly reshaped by the Russian conquest, which introduced cereals, pathogens and Christianity from 1632 CE. However, the biological impact of these transformations remains unknown. Here, we generated extensive ancient DNA data to elucidate contemporary changes in Yakut genomic diversity and oral microbiomes. We found Yakut origins tracing back to local populations that admixed with trans-Baikal groups migrating as the Great Mongol Empire spread. Despite the Russian conquest, the Yakut gene pool and oral microbiomes appeared largely stable, though smallpox strains distinct from those documented in Europe by ~1650 CE circulated. Marital practices generally maintained low consanguinity, with the exception of one female bearing the latest markers of traditional shamanism, who was the daughter of second-degree relatives.

  Study EGAS50000001329

• Whole-genome sequencing in 14 cases and whole-exome sequencing in 90 cases of Chinese ESCC

  Esophageal cancer is one of the most aggressive cancers and the sixth leading cause of cancer death worldwide1. Approximately 70% of the global esophageal cancers occur in China and over 90% histopathological forms of this disease are esophageal squamous cell carcinoma (ESCC)2-3. Currently, there are limited clinical approaches for early diagnosis and treatment for ESCC, resulting in a 10% 5-year survival rate for the patients. Meanwhile, the full repertoire of genomic events leading to the pathogenesis of ESCC remains unclear. Here we show a comprehensive genomic analysis in 158 ESCC cases, as part of the International Cancer Genome Consortium (ICGC) Research Projects (http://icgc.org/icgc/cgp/72/371/1001734). We conducted whole-genome sequencing in 14 ESCC cases and whole-exome sequencing in 90 cases.

  Study EGAS00001001487

• Evolutionary analysis of pancreatic cancer and coexistent precursor lesions using whole exome sequencing data

  Most adult carcinomas develop from noninvasive precursor lesions, a progression that is supported by genetic analysis. Further, the evolution of these lesions contextualizes the dynamics of advanced stage disease. We analyzed the somatic variants of co-existing pancreatic cancers and precursor lesions sampled from distinct regions of the same pancreas. After inferring evolutionary relationships, we found that the ancestral cell had initiated and clonally expanded to form one or more lesions, and that subsequent driver gene mutations eventually led to a pancreatic cancer. We also found that this multi-step progression generally spans many years. Our data suggest that independent, high-grade pancreatic lesions observed in a histologic cross section often represent a single neoplasm that can spread and colonize the ductal system, accumulating spatial and genetic divergence over time.

  Study EGAS00001002778

• single nuclei RNASeq of 5 regions of the human prenatal brain

  Data generated through single nuclei RNA sequencing on 5 regions of the brain (frontal cortex, ganglionic eminence, hippocampus, thalamus and cerebellum) from 3 fetuses (two of 14 and one of 15 post-conception weeks, all female). Tissue was acquired from the MRC-Wellcome Trust Human Developmental Biology Resource (HDBR) with ethical approval. snRNA-seq libraries were prepared from ∼10,000 nuclei from each sample using Chromium Single Cell 3ʹ (v3) reagents (10X Genomics). Quality control of libraries was performed using the Agilent 5200 Fragment Analyzer before sequencing on an Illumina NovaSeq 6000 to a depth of at least 865 million (median = 1.01 billion) read pairs per library. Raw sequencing data were converted into FASTQ files. For a full description of data generation, please see Cameron et al, Biological Psychiatry 2022, https://doi.org/10.1016/j.biopsych.2022.06.033.

  Study EGAS00001006537

• BLUEPRINT Hematopoietic Stem/Progenitor Cell Methylomes

  An optimized whole genome bisulfite sequencing protocol (µWGBS, Farlik et al. 2015 Cell Reports) was used to establish DNA methylation profiles of FACS-purified stem and progenitor cells types of the human blood lineage. Most cell types were sorted from the peripheral blood of three donors with eight pools of ten cells, two pools of 50 cells, and one pool of 1000 cells. HSCs and MPPs were also sorted from fetal liver (HSCs only), cord blood, and bone marrow. Single-cell methylomes using the scWGBS protocol (Farlik et al. 2015 Cell Reports) were established for six cell types (HSC, MPP, CMP, GMP, CLP, MLP0). Gene expression profiling using the Smart-seq2 protocol (Picelli et al. 2013 Nature Methods) was done for nine stem/progenitor cell types (HSC, MPP, CMP, GMP, CLP, MLP0, MLP1, MLP2, MLP3).

  Study EGAS00001002070