14480 results for "PLOS+ONE+Pennsylvania+German+ACS+language+code+pdc+open+access+study"

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• Characterization of the cellular microenvironment in fibrostenotic Crohn’s disease

  Crohn's disease (CD) is marked by recurring intestinal inflammation and tissue injury, often resulting in fibro-stenosis and bowel obstruction, necessitating surgical intervention with high recurrence rates. To elucidate to the mechanisms underlying fibro-stenosis in CD, we analysed the transcriptome of cells isolated from the transmural ileum of CD patients, including a trio of lesions from each patient: non-affected, inflamed, and stenotic ileum samples, and compared them with samples from non-CD patients. Our computational analysis revealed that pro-fibrotic signals from a subset of monocyte-derived cells induced a disease-specific fibroblast population, resulting in chronic inflammation and tissue fibrosis. Our findings suggest that the myeloid-stromal axis may offer a promising therapeutic target to prevent fibro-stenosis in CD.

  Study EGAS50000000382

• Defining T cell States Associated with Response to Checkpoint Immunotherapy in Melanoma

  Checkpoint blockade therapy using antibodies targeting CTLA4, PD1 or PDL1 have changed the way cancer patients with advanced disease are being treated, as evident by their FDA approval in a wide variety of malignancies, and their ability to induce high response rates when compared to conventional therapies (e.g. chemotherapy). However, even in melanoma, despite the high response rate, most patients are refractory to therapy or acquire resistance in 10-12 months. To identify key immunological elements coupled with response or resistance to checkpoint immunotherapy, we performed an unbiased analysis on 16,291 CD45+ immune cells from 32 patients (48 samples) treated with checkpoint therapy (anti-PD1=37; anti-PD1/CTLA4=11), using single cell transcriptomics. Initial unsupervised clustering of all CD45+ cells identified 11 clusters. When examining the association of these clusters with clinical outcome, we found that two clusters (B-cells, p=0.005; memory T-cells, p=0.03) were significantly enriched in responder lesions while 4 clusters (monocytes/macrophages, p=0.003; dendritic cells, p=0.015; exhausted CD8+ T-cells, p=0.005; and exhausted/cell-cycle lymphocytes, 1.3x10-5) are enriched in non-responder lesions. Next, by leveraging our unbiased single cell approach, we identified not only clusters but also specific markers associated with either responder lesions (PLAC8, LTB, LY9, SELL, TCF7, IGKC and CCR7) or non-responder ones (CCL3, CD38, HAVCR2, ENTPD1 and WARS), many of which were not previously reported to be associated with clinical outcome to checkpoint therapy. Due to the importance of CD8+ T-cells in controlling tumors, the significant association of T-cell states with clinical outcome, and their high abundance in melanoma tumors, we next focused our analysis on CD8+ T-cells and identified 2 main clusters CD8_G (with increased expression of genes linked to memory) and CD8_B (enriched for genes linked to cell dysfunction), that were significantly enriched in responder (CD8_G, p=1.4x10-6) and non-responder (CD8_B, p=0.005) lesions, respectively. Since cells with both states coexist in each of the responder and non-responder lesions, we decided to calculate the ratio between the number of cells in these 2 clusters and observed a significant separation between responders (CD8_G/CD8_B>1) and non-responders (CD8_G/CD8_B<1) when looking at all samples, baseline or post samples separately. Similar results were detected when looking at the expression of a single transcription factor, TCF7, in CD8 T-cells in an independent cohort (n=43) using a simple immunofluorescence assay. Additionally, we validated the identity and function of some of the newly identified cell states as well as their epigenetic landscape, and found that cells expressing the inhibitory molecules CD39 and TIM3, on top of being enriched in non-responder lesions, are likely to play a crucial role in T-cell exhaustion in melanoma. Collectively, our study provides extensive unbiased data in human tumors for discovery of predictors and therapeutic targets to checkpoint immunotherapy.

  Study phs001680

• Robust detection of translocations in lymphoma FFPE samples using Targeted Locus Capture-based sequencing

  Chromosomal translocations with immunoglobin (IG) loci are the classic drivers in a large subset of B-cell lymphomas. Detection of these translocations is important for confirmation of diagnosis and for prognosis and therapy decisions. Currently, molecular diagnosis of translocations in lymphomas is not addressed well by Next Generation Sequencing (NGS). The standard method for detection of translocations is Fluorescence In Situ Hybridization (FISH), which is labor-intensive, and can be difficult to interpret. There is a need for a robust technology that can be standardized. Targeted Locus Capture (TLC) selectively enriches and sequences entire genes based on the crosslinking of physically proximal sequences, and thereby enables complete sequencing of genes of interest, including detection of large structural variants. Because the technology is based on the crosslinking and fragmenting of DNA, it has particular advantages in the analysis of Formalin-Fixed, Paraffin-Embedded (FFPE) samples, in which DNA is inherently crosslinked and fragmented. In order to validate the FFPE-TLC technology as a novel approach for translocation detection in lymphoma samples, we have developed a panel assay containing genes with frequent translocations (MYC, BCL2, BCL6, IG loci). With this assay we have analyzed >140 lymphoma and control FFPE samples of variable input amounts and qualities that had previously been analyzed with FISH, and a subset also with standard targeted NGS. Good concordance with FISH results was observed for both translocation positive and negative samples. In 10 cases for which FFPE-TLC detected a relevant fusion and FISH had been called negative, discordance could be explained by higher sensitivity of FFPE-TLC or by inconclusive FISH results. In a specific case, FFPE-TLC detected a small-distance rearrangement on chromosome 3 that caused a BCL6 fusion but led to insufficient and therefore undetectable break-apart with FISH. Secondly, the FFPE-TLC approach was tested on a set of 19 B-cell lymphoma FFPE samples that had previously been analyzed using standard targeted NGS and FISH and was enriched for discordant results between these methods. FFPE-TLC-based NGS enables more robust translocation calling as the detection relies on broad sequencing coverage across the translocation partner rather than on breakpoint sequences only. In 3 cases, FFPE-TLC could proof false negative calls in standard targeted NGS due to breakpoints located in regions difficult to capture or to sequence. In 1 case, standard targeted NGS had made a false positive call on a breakpoint sequence that was shown to be caused by a small insertion rather than a genuine translocation. This study shows that FFPE-TLC promises to be a robust alternative for FISH analysis and standard targeted NGS procedures in lymphoma diagnostics and possibly in other cancers with frequent structural variants. The FFPE-TLC approach enables a single, DNA-based NGS test detecting both small mutations and translocations.

  Study EGAS00001004760

• Recording physiological history of cells with chemical labeling.

  Recordings of the physiological history of cells provide insights into biological processes, yet obtaining such recordings is a challenge. To address this, we introduce a method to record transient cellular events for later analysis. We designed proteins that become labeled in the presence of both a specific cellular activity and a fluorescent substrate. The recording period is set by the presence of the substrate, whereas the cellular activity controls the degree of the labeling. The use of distinguishable substrates enabled the recording of successive periods of activity. We recorded protein-protein interactions, G-protein-coupled receptor activation and elevations in intracellular calcium. Recordings of elevated calcium levels allowed selections of cells from heterogenous populations for transcriptomic analysis and tracking of neuronal activities in flies and zebrafish.

  Study EGAS50000000056

• DNA Double Strand Breaks in KMT2A-Rearranged AML patients

  DNA breakage at specific rearrangement-participating genes, which are more sensitive to a range of environmental and chemotherapeutic agents than other regions of the human genome, contributes to the generation of leukemia-causing rearrangements, and can be used as a predictor of susceptibility to cancer caused by gene rearrangements. As a direct proof-of-principle regarding the feasibility of employing fragile site breakage to identify and monitor high-risk populations to allow personalized treatments, genome-wide DNA break mapping/sequencing was used to determine whether preferential DNA breaks are generated at the major breakpoint regions of KMT2A in AML remission patients with previously diagnosed KMT2A rearrangement. We are submitting break mapping data from three patients with KMT2A rearrangements and three non-fusion patients, with and without etoposide treatments.

  Study phs002804

• Single Cell Analysis of Pulmonary Fibrosis

  Pulmonary fibrosis is a heterogenous syndrome in which fibrotic scar replaces normal lung tissue. We performed massively parallel single-cell RNA-Seq on lung tissue from eight lung transplant donors and eight patients with pulmonary fibrosis. Combined with in situ RNA hybridization, with amplification, these data provide a molecular atlas of disease pathobiology. We identified a distinct, novel population of profibrotic alveolar macrophages exclusively in patients with fibrosis. Within epithelial cells, the expression of genes involved in Wnt secretion and response was restricted to non-overlapping cells. We identified rare cell populations including airway stem cells and senescent cells emerging during pulmonary fibrosis. Analysis of a cryobiopsy specimen from a patient with early disease supports the clinical application of single-cell RNA-Seq to develop personalized approaches to therapy.

  Study phs001750

• Genomic sequencing of Pediatric Rhabdomyosarcoma

  Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood accounting for approximately 350 newly diagnosed cases yearly in the United States. With the development of multimodal chemotherapy regimens, relapse-free survival rates have improved to 70-80% in patients with localized disease albeit with significant toxicity. Unfortunately, despite aggressive treatment, patients with metastatic or recurrent disease continue to suffer from high mortality. Further characterization of the genetic events underlying this tumor type is critical for the development of more effective diagnostic, prognostic and therapeutic strategies. In a collaborative effort between the National Cancer Institute, the Children's Oncology Group, and the Broad Institute, we use a combination of whole-genome and whole-exome sequencing to characterize the landscape of somatic alterations in 147 tumor/normal pairs.

  Study phs000720

• Targeted Sequencing of Primary ER-positive Breast Tumors Treated with 5 Years of Tamoxifen

  Targeted massively parallel sequencing analysis was conducted on DNA extracted from archived 22-28 year old, formalin-fixed primary breast tumors from 625 patents from British Columbia treated with five years of adjuvant tamoxifen monotherapy and followed for over 10 years. Genes were selected for targeted sequencing by review of existing large-scale breast cancer sequencing studies and breast cancer literature. In total, 83 genes were identified and 3,029 probes were designed to tile across all known exons. Illumina sequencing libraries were constructed, indexed, pooled, and enriched for target sequences by hybrid-capture followed by sequencing of paired-end 100bp reads. All samples met minimum quality controls of 80% targeted space covered at 20X or greater. On average, each sample had 336M aligned bases and a mean coverage of 135.8X.

  Study phs001234

• The Longevity Genes Project

  Aging is a complex, universal condition leading to the functional decline of all cells and organisms, and to major national and global public health problems. Although aging is the major risk factor for developing most adult-onset diseases, systematic investigations into the fundamental physiology, biology and genetics of aging are only just beginning. In the Longevity Genes Project at Albert Einstein College of Medicine, Dr. Nir Barzilai and his team conducted genetic research on more than 500 healthy elderly people between the ages of 95 and 112, and on their children. The identification of longevity genes by Einstein researchers could lead to new drug therapies that might help people live longer, healthier lives and avoid or significantly delay age-related diseases such as Alzheimer's disease, type 2 diabetes and cardiovascular disease.

  Study phs000584

• HNPCC-Sys: Molecular Characterization of Lynch Syndromes

  Lynch Syndrome (LS) tumors are characterized by constitutional mutations in DNA mismatch-repair genes. Colorectal cancers (CRCs) are the predominant tumor type in patients with LS. Here, we have used whole-genome and transcriptome sequencing of LS- CRC to find similarities and differences of mutation and gene expression characteristics between LS-CRC and sporadic CRC (data provided by TCGA via dbGaP). Furthermore, we were interested in the molecular heterogeneity of LS-CRC. We have performed a molecular characterization of LS-tumors and of matched tumor-distant reference colonic mucosa based on whole-genome DNA- and RNA-sequencing analyses. Our data indicates the existence of two subgroups of LS-CRCs, G1 and G2, where G1 tumors show a higher number of somatic mutations, higher microsatellite slippage and a different mutation spectrum.

  Study phs001407