Ontology highlight
ABSTRACT:
PROVIDER: PRJNA343397 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Our analysis reveals an extensive methylomic drift between normal squamous esophagus and BE tissues in nonprogressed BE patients, with differential drift affecting 4024 (24%) of 16,984 normally hypomethylated cytosine-guanine dinucleotides (CpGs) occurring in CpG islands. The majority (63%) of islands that include drift CpGs are associated with gene promoter regions. Island CpGs that drift have stronger pairwise correlations than static islands, reflecting collective drift consistent with processive DNA methylation maintenance. Individual BE tissues are extremely heterogeneous in their distribution of methylomic drift and encompass unimodal low-drift to bimodal high-drift patterns, reflective of differences in BE tissue age. Further analysis of longitudinally collected biopsy samples from 20 BE patients confirm the time-dependent evolution of these drift patterns. Drift patterns in EAC are similar to those in BE, but frequently exhibit enhanced bimodality and advanced mode drift. To better understand the observed drift patterns, we developed a multicellular stochastic model at the CpG island level. Importantly, we find that nonlinear feedback in the model between mean island methylation and CpG methylation rates is able to explain the widely heterogeneous collective drift patterns. Using matched gene expression and DNA methylation data in EAC from TCGA and other publically available data, we also find that advanced methylomic drift is correlated with significant transcriptional repression of ~ 200 genes in important regulatory and developmental pathways, including several checkpoint and tumor suppressor-like genes. Taken together, our findings suggest that epigenetic drift evolution acts to significantly reduce the expression of developmental genes that may alter tissue characteristics and improve functional adaptation during BE and EAC progression.
2017-10-31 | GSE104707 | GEO
Project description:The evolution of human bipedalism exposed the knee to unique biomechanical challenges, requiring changes in knee anatomy giving rise to the modern-day configuration. In order to better understand the relationship between derived knee morphology and the genetic factors associated with osteoarthritis risk, we performed epigenetic profiling of murine forelimb/hindlimb growth plates to identify regulatory elements shaping formation of specific knee structures, identifying signals of ancient positive selection upon which more recent genetic drift overlaps risk-associated loci. Our functional analyses of an osteoarthritis-risk variant within a reproducibly-associated locus establishes a novel model for studying this degenerative disease.
2020-04-16 | GSE122877 | GEO
Project description:Background: The clonal basis of relapse in acute lymphoblastic leukemia (ALL) is complex and not fully understood. Methods: Next-generation sequencing (NGS), array comparative genomic hybridization (aCGH), and multiplex-ligation-dependent probe amplification (MLPA) were carried out in matched diagnosis-relapse samples from 13 B-cell precursor acute lymphoblastic leukemia (BCP-ALL) patients to identify patterns of genetic evolution that could account for the phenotypic changes associated with disease relapse. Findings: The integrative genomic analysis of aCGH, MLPA and NGS revealed that 100% of BCP-ALL patients showed at least one genetic alteration at diagnosis and relapse. In addition, there was a significant increase in the frequency of chromosomal lesions at the time of relapse (median, 6 alterations per sample) relative to that at diagnosis (median, 47 alterations) (p = 0.019). The combination of MLPA and aCGH techniques showed that IKZF1 was the most frequently deleted gene. Notably, TP53 was the most frequently mutated gene at relapse (31%). Two TP53 mutations were detected only at relapse, whereas the three others showed an increase of their mutational burden at relapse. Interpretation: Clonal evolution patterns were heterogeneous, involving acquisition, loss and maintenance of lesions at relapse. Therefore, this study confirmed that BCP-ALL is a genetically dynamic disease with distinct genetic profiles at diagnosis and relapse. The combination of the NGS, aCGH, and MLPA approaches enables better molecular characterization of the genetic profile in ALL patients during the evolution from diagnosis to relapse.
2020-08-12 | GSE128031 | GEO
Project description:Molecular profiling of breast cancer has achieved great depth in defining the mutational landscapes and molecular profiles of primary tumors, though little is still known regarding cancer evolution into a recurrence. Proteogenomic workflows are particularly useful in defining the multi-layered biology of complex diseases by combining genomic, transcriptomic, and proteomic technologies so to inform not only on mutational processes, but also on their repercussion at the effector level, proteins. We employed our recently developed proteogenomic workflow to analyze a cohort of 27 primary breast cancers and their matched loco-regional recurrences by whole genome sequencing, RNA sequencing, and mass spectrometry.
2023-02-03 | PXD032266 | Pride
Project description:Wild-type laboratory strains of model organisms are typically kept in isolation for many years, with the action of genetic drift and selection on mutational variation causing lineages to diverge with time. Natural populations from which such strains are established, show that gender-specific interactions in particular drive many aspects of sequence level and transcriptional level variation. Here, our goal was to identify genes that display transcriptional variation between laboratory strains of Drosophila melanogaster, and to explore evidence of gender-biased interactions underlying that variability. Keywords: expression analysis; gender and genotype effects
2008-08-01 | GSE9149 | GEO
Project description:Wild-type laboratory strains of model organisms are typically kept in isolation for many years, with the action of genetic drift and selection on mutational variation causing lineages to diverge with time. Natural populations from which such strains are established, show that gender-specific interactions in particular drive many aspects of sequence level and transcriptional level variation. Here, our goal was to identify genes that display transcriptional variation between laboratory strains of Drosophila melanogaster, and to explore evidence of gender-biased interactions underlying that variability. Experiment Overall Design: Three replicate groups of males and virgin females were collected for each sex and genotype combination. Total RNA was extracted independently for each of the 30 samples (five lines x two sexes x three replicates)
2008-10-20 | E-GEOD-9149 | biostudies-arrayexpress
Project description:Many normal tissues undergo age-related DNA methylation drift providing a quantitative measure of tissue age. However this drift has not been demonstrated in neoplastic tissues. Here we identify and validate 781 CpG-islands (CGIs) that undergo significant methylomic drift in normal colorectal tissues continue to drift in neoplasia and remain significantly correlated with one another across tissue samples. However compared with normal colon this drift advances (~3-4 fold) faster in neoplasia consistent with increased cell proliferation during neoplastic progression. Furthermore we show that the observed drift patterns are broadly consistent with modeled adenoma-carcinoma sojourn time distributions from colorectal cancer (CRC) incidence data. These results support the hypothesis that beginning with the founder premalignant cell cancer precursors frequently sojourn for decades before turning into cancer which implies that the founder cell typically arises early in life. We estimate that at least 77-89% of the observed drift variance in distal and rectal tumors is explained by stochastic variability associated with neoplastic progression while only 55% of the variance is explained for proximal tumors. However >50% of identified gene-CGI pairs in the proximal colon that undergo drift are significantly and mainly negatively correlated with cancer gene expression suggesting that methylomic drift participates in the clonal evolution of CRCs. Significance: Methylomic drift advances in colorectal neoplasia consistent with extended sojourn time distributions explaining a significant fraction of epigenetic heterogeneity in CRCs. Importantly the estimated long-duration premalignant sojourn times suggest that early dietary and lifestyle interventions may be more effective than later changes in reducing CRC incidence.
2019-04-19 | GSE113904 | GEO
Project description:Mutation generates the heritable variation that genetic drift and natural selection shape. In classical quantitative genetic models, drift is a function of the effective population size and acts uniformly across traits, while mutation and selection act trait-specifically. We identified thousands of quantitative trait loci (QTL) influencing transcript abundance traits in a cross of two C. elegans strains; although trait-specific mutation and selection explained some of the observed pattern of QTL distribution, the pattern was better explained by trait-independent variation in the intensity of selection on linked sites. Our results suggest that traits in C. elegans exhibit different levels of variation less because of their own attributes than because of differences in the effective population sizes of the genomic regions harboring their underlying loci.
2010-10-01 | GSE23857 | GEO
Project description:Recurrences of diffuse large B-cell lymphomas (DLBCL) result in significant morbidity and mortality, but their underlying genetic and biological mechanisms are unclear. Clonal relationship in DLBCL relapses so far is mostly addressed by the investigation of immunoglobulin (IG) rearrangements, therefore lacking deeper insights into genome-wide lymphoma evolution. We studied mutations and copy number aberrations in 20 paired relapsing and 20 non-relapsing DLBCL cases aiming to test the clonal relationship between primaries and relapses, to track tumors’ genetic evolution and to investigate the genetic background of DLBCL recurrence. Three clonally-unrelated DLBCL relapses were identified (15%). Also, two distinct patterns of genetic evolution in clonally-related relapses were detected: (1) early-divergent/branching evolution from a common progenitor in 6 patients (30%), and (2) late-divergent/linear progression of relapses in 11 patients (65%). Analysis of recurrent genetic events identified potential early drivers of lymphomagenesis (KMT2D, MYD88, CD79B and PIM1). The most frequent relapse-specific events were additional mutations in KMT2D and alterations of MEF2B. SOCS1 mutations were exclusive to non-relapsing DLBCL, whereas primaries of relapsing DLBCL more commonly displayed gains of 10p15.3-p12.1 containing the potential oncogenes PRKCQ, GATA3, MLLT10 and ABI1. Altogether, our study expands knowledge on clonal relationship, genetic evolution and mutational basis of DLBCL relapses.
2016-06-01 | GSE65720 | GEO
Project description:Cancer is a disease of the genome. Many genomic abnormalities have been found in a variety of cancer types, which are believed to be attributable to tumorigenesis as well as resistance to treatment and recurrence. Genomic heterogeneity in the same type of cancer or within a tumor reveals the complexity of cancer biology so that intratumor heterogeneity has become an inherent feature of cancer. In this study, we use whole-exome sequencing and array comparative genomic hybridization technology to examine the mutational profiling and copy number changes from multi-region samples within an esophageal cancer in order to understand the genomic phylogeny in the evolution of intratumor heterogeneity in esophageal cancer.
2014-12-31 | GSE60625 | GEO