12155 results for "cancer rna-seq"

in 16.47 milliseconds.

• Mutational signatures in normal tissues of patients treated with clinical stage G-quadruplex binder CX5461

  Drug induced photoreactions following exposure to UVA have been documented for several therapeutic compound classes, including psoralens and fluoroquinolones. CX5461, a quinolone-derived small molecule currently in phase 1 studies for cancer treatment, has been shown to be a clinically significant UV photosensitizer. Here we examined the mutagenic spectrum of CX5461 in normal tissues of patients undergoing treatment, by comparing deep whole genome sequencing (WGS) from skin biopsies taken from non-sun exposed areas pre and post drug exposure of patients in the Canadian Cancer Clinical Trials Group (CCTG) IND.231 trial (NCT02719977). We show that a low burden of SNVs (<100) and indels (<40) mutations was detected in post CX5461 skin biopsies, with a pattern resembling background or sequencing artefact signatures. To further characterize the mutational pattern of CX5461 photoreactivity, we compared mutational profiles of human retinal pigment epithelial cells exposed to UVA, CX5461, or a combination of both UV and CX5461. Treatment with CX5461 or UVA alone, resulted in a low SNV burden. In contrast, human cells exposed to UVA and CX5461 had a two to four orders higher mutational burden, with a distinct mutational pattern characterized by T>A, T>C mutations, dissimilar to that of UV alone or CX5461 alone. Our results suggest that human exposure to CX5461 alone is not associated with high levels of single base mutagenesis. However, CX5461 is a very potent UV photosensitizer, underscoring the need for adequate UV screening and controls when studying the effects of photosensitizing small molecules on single base DNA variation.

  Study EGAS50000001145

• The genomic landscape of pediatric acute lymphoblastic leukemia

  Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer and arises from B- or T-lineage lymphocyte precursors. ALL comprises dozens of subtypes, and genomic analyses have largely been performed within these subtypes. Here we analyze pediatric ALL genomes across all subtypes, including 768 whole genomes, 1,729 exomes, and 1,889 transcriptomes in 2,754 patients. Most ALL subtypes harbor 4 or more driver alterations per sample, similar to adult cancers, despite low mutation burdens. Hyperdiploid B-ALL copy gains are likely acquired early and synchronously, with copy gains occurring before ultraviolet-induced mutations. By contrast, ultraviolet-induced mutations precede copy gains in iAMP21 B-ALL. Overall, we identified 378 putative ALL driver genes. Most driver alterations vary in prevalence across ALL subtypes, with B-ALL enriched for Ras and B-lineage-related alterations, and T-ALL enriched for PI3K, JAK, and cell cycle alterations. Most B-ALL (54.3%) and T-ALL (51.2%) samples bear at least one rare driver gene alteration (present in less than 2% of samples), including 30 putative novel cancer driver genes associated with ubiquitination, SUMOylation, non-coding, and other functions. Known or novel alterations associated with poor outcomes in specific subtypes include TBL1XR1 alterations in ETV6-RUNX1 patients, CREBBP in Ph-like-CRLF2, SETD2 in hyperdiploid, and PTEN in TAL1 patients. Intriguingly, DUX4 and KMT2A subtypes separate into CEBPA/FLT3- or NFATC4-expressing subgroups with potential clinical implications. Together, these results deepen understanding of ALL etiology and outcomes, and facilitate ALL model development.

  Study EGAS00001005250

• Mutation-specific non-canonical pathway of PTEN as a distinct therapeutic target for glioblastoma

  PTEN is one of most frequently altered tumor suppressor genes in malignant tumors. The dominant negative effect of PTEN alteration suggests that aberrant function of PTEN mutation might be more disastrous than deletion, the most frequent genomic event in glioblastoma (GBM). This study aimed to understand the functional properties of various PTEN missense mutations and to investigate their clinical relevance. The genomic landscape of PTEN alteration was analyzed using the Samsung Medical Center GBM cohort and validated via The Cancer Genome Atlas dataset. Several hot-spot mutations were identified, and their subcellular distributions and phenotypes were evaluated. We established a library of cancer cell lines that over-express these mutant proteins using the U87MG and patient-derived cell models lacking functional PTEN. PTEN mutations were categorized into two major subsets: missense mutations in the phosphatase domain and truncal mutations in the C2 domain. We determined the subcellular compartmentalization of four mutant proteins (H93Y, C124S, R130Q, and R173C) from the former group and found that they had distinct localizations; those associated with invasive phenotypes (‘edge mutations’) localized to the cell periphery, while the R173C mutant localized to the nucleus. Invasive phenotypes derived from edge substitutions were unaffected by an anti-PI3K/Akt agent but were disrupted by microtubule inhibitors. PTEN mutations exhibit distinct functional properties with regard to their subcellular localization. Further, some missense mutations (‘edge mutations’) in the phosphatase domain caused enhanced invasiveness associated with dysfunctional cytoskeletal assembly, thus suggesting it to be a potent therapeutic target.

  Study EGAS00001004753

• Analysis of the Elements Involved in the Enrichment of a Panel of Genomic Regions by Nanopore Sequencing Using Adaptive Sampling

  DNA sequencing using nanopore technologies with the affordable MinION device is useful for the identification and characterization of structural variants, long haplotypes, sequencing of repetitive regions and identification of epigenetic modifications. The main limitation of this approach is the low coverage obtained, which might be avoided by adaptive sampling, a computationally controlled method of enrichment for targeted genomic regions. This study dissects the factors involved in the enrichment by adaptive sampling of a panel of 18 human genome regions containing 20 genes implicated in breast cancer sequenced in 16 patients with familial breast cancer negative for NGS screening. An average coverage of 2.0x was obtained for the whole genome and 5.1x for selected regions. Sequencing time was the main factor improving coverage. The selection of long reads (&amp;gt;1 Kb) did not improve the enrichment. The length of the selected region, which in our study ranged from 126 to 565 Kb, did not play a significant role in enrichment. However, the region containing PMS2 showed significantly lower coverage, which could be explained by the high number of PMS2 pseudogenes (N = 14), which were also enriched. Our study shows new evidence of enrichment obtained by adaptive sampling in a panel of genomic regions and shows parameters, the relevance of sequencing time and the role of pseudogenes, that improve the enrichment yield with no library reloading or GPU use, data useful for a more efficient application of this procedure in future studies.

  Study EGAS00001007375

• Selenium Chemoprevention: Benefits and Harms

  Selenium is a trace element that may have anti-carcinogenetic effect, but heterogenous treatment effects have been observed. This genome-wide association study investigates if genetic variation modifies the effect of selenium chemoprevention in the Selenium and Celecoxib Trial, a randomized, double-blind, placebo-controlled trial conducted at the University of Arizona Cancer Center. The objective of the clinical trial was to determine whether daily intake of 200 &#181;g/d of selenium as a supplement could reduce the risk for developing metachronous colorectal adenomas. The study participants were recruited between 2001 and 2011. Genome-wide association study was performed for 1,323 study participants who provided blood sample at the time of study entry.

  Study phs002283

• The Genomics of Pilocytic Astrocytoma Formation in Neurofibromatosis Type 1

  Neurofibromatosis type 1 (NF1) inherited cancer predisposition syndrome is one of the most common autosomal dominant tumor predisposition syndromes in which affected individuals develop brain tumors. These low-grade glial neoplasms (pilocytic astrocytomas) typically arise in children younger than 7 years of age and are hypothesized to result from a combination of germline and acquired somatic NF1 tumor suppressor gene mutations. In this study, whole genome sequence analysis was performed on three NF1-associated pilocytic astrocytoma tumors (NF1-PA) and matched normal blood samples to establish the genomic landscape of NF1-PA. These data support the existence of multiple distinct mechanisms (mutation, LOH, and methylation) underlying somatic NF1 inactivation in NF1-PA tumors.

  Study phs000563

• Genomic Landscape of High-Grade Neuroendocrine Neoplasms

  This project is a multi-omics study of high grade (grade 3) neuroendocrine neoplasms across diverse organs. Genomic analysis using low-pass whole genome sequencing for copy number analysis, whole exome sequencing and whole transcriptomic sequencing using RNAseq were performed. As high grade neuroendocrine neoplasms are highly lethal with a median survival of approximately 7 months, new insights are urgently needed for better prognosis, diagnosis and management. This study focuses on gene and pathway discoveries in this cancer, and includes samples from a diverse set of organs, including the lungs, gastroenteropancreatic tract, breast, prostate, head and neck and bladder. This study was made possible by a generous donation from The Helen B. Rodde Fund.

  Study phs002070

• Whole Exome Sequencing Analysis of Carfilzomib-Related Cardiotoxicity in Multiple Myeloma Patients

  This study investigated the contribution of germline genetic variants in protein-coding genes in carfilzomib-related cardiovascular adverse events among patients with multiple myeloma using whole-exome sequencing (WES) analysis. We analyzed 247 patients with multiple myeloma who had been treated with carfilzomib at the Moffitt Cancer Center. We identified a missense mutation in the TMSB10/TRABD2A locus that appeared to be associated with a higher risk for cardiovascular adverse events in these patients. In this submission, we will provide all the genotype data along with the phenotype data of whether or not a patient developed cardiovascular adverse events after carfilzomib treatment and all the covariates used in this analysis.

  Study phs003308

• Fragmentomics profiling and quantification of plasma Epstein-Barr virus DNA enhance prediction of future nasopharyngeal carcinoma.

  This study evaluated the clinical utility of fragmentomics analysis of plasma Epstein-Barr virus (EBV) DNA in nasopharyngeal carcinoma (NPC) screening. The first-round EBV-positive blood samples from a two-round large-scale prospective NPC screening cohort were analyzed. The EBV DNA of subjects who developed NPC in the second round displayed a distinctive mononucleosomal size pattern, an NPC-associated end motif profile, and aberrations in methylation deduced by fragmentomics-based methylation analysis (FRAGMA). Subjects with these aberrant fragmentomics features and higher EBV DNA quantity showed a dramatically increased risk of NPC development, demonstrating the potential of plasma DNA fragmentomics in predicting future cancer risk.

  Study EGAS50000000395

• DNA Replication Speed controls Epigenome Integrity and T Cell Fate

  Epigenetic mechanisms maintain cellular identities by enforcing stable, cell type-specific transcriptional programs while also allowing regulated plasticity for adaptations to environmental cues like differentiation signals. Dysregulation of this dual capacity has been linked to cancer and chronic inflammation, with the regulatory mechanisms remaining poorly understood. Here, we identify DNA replication speed as a physiological regulator controlling epigenome stability and plasticity. Using T-lymphocytes as a model, we demonstrate that fast DNA replication speed impaired epigenome stability, causing DNA methylation maintenance errors at cell type-specific enhancers and heterochromatin, ultimately leading to compromised cell function. However, accelerated DNA replication speed supported epigenome plasticity during differentiation, promoting successful cell-type transitions

  Study EGAS50000001273