Search results for "Microarray"

Gene Expression Analysis Uncovers Similarity and Differences Among Burkitt Lymphoma Subtypes.

2011

Abstract Abstract 2494 Background. Burkitt lymphoma (BL) is currently listed in the WHO classification of lymphoid tumors as a single genetic and morphological entity with variation in clinical presentation. In particular, three clinical subsets of BL are recognized: endemic (eBL), sporadic (sBL) and immunodeficiency associated (ID-BL). Each affects different populations and can present with different features. So far, possible differences in their gene expression profiles (GEP) have not been investigated. In this study we aimed to 1) assess whether BL subtypes present with differences in their GEP; 2) investigate the relationship of the different BL subtypes with the non-neoplastic cellula…

Estimating the extent of horizontal gene transfer in metagenomic sequences

2008

Abstract Background Although the extent of horizontal gene transfer (HGT) in complete genomes has been widely studied, its influence in the evolution of natural communities of prokaryotes remains unknown. The availability of metagenomic sequences allows us to address the study of global patterns of prokaryotic evolution in samples from natural communities. However, the methods that have been commonly used for the study of HGT are not suitable for metagenomic samples. Therefore it is important to develop new methods or to adapt existing ones to be used with metagenomic sequences. Results We have created two different methods that are suitable for the study of HGT in metagenomic samples. The …

2014

Introduction: Many studies examine gene expression data that has been obtained under the influence of multiple factors, such as genetic background, environmental conditions, or exposure to diseases. The interplay of multiple factors may lead to effect modification and confounding. Higher order linear regression models can account for these effects. We present a new methodology for linear model selection and apply it to microarray data of bone marrow-derived macrophages. This experiment investigates the influence of three variable factors: the genetic background of the mice from which the macrophages were obtained, Yersinia enterocolitica infection (two strains, and a mock control),and treat…

Aberrantly activated claudin 6 and 18.2 as potential therapy targets in non-small-cell lung cancer

2014

Claudins (CLDNs) are central components of tight junctions that regulate epithelial-cell barrier function and polarity. Altered CLDN expression patterns have been demonstrated in numerous cancer types and lineage-specific CLDNs have been proposed as therapy targets. The objective of this study was to assess which fraction of patients with non-small-cell lung cancer (NSCLC) express CLDN6 and CLDN18 isoform 2 (CLDN18.2). Protein expression of CLDN6 and CLDN18.2 was examined by immunohistochemistry on a tissue microarray (n=355) and transcript levels were supportively determined based on gene expression microarray data from fresh-frozen NSCLC tissues (n=196). Both were analyzed with regard to …

MGFM: a novel tool for detection of tissue and cell specific marker genes from microarray gene expression data

2015

Background Identification of marker genes associated with a specific tissue/cell type is a fundamental challenge in genetic and cell research. Marker genes are of great importance for determining cell identity, and for understanding tissue specific gene function and the molecular mechanisms underlying complex diseases. Results We have developed a new bioinformatics tool called MGFM (Marker Gene Finder in Microarray data) to predict marker genes from microarray gene expression data. Marker genes are identified through the grouping of samples of the same type with similar marker gene expression levels. We verified our approach using two microarray data sets from the NCBI’s Gene Expression Omn…

Analysis of biological prognostic factors using tissue microarrays in neuroblastic tumors

2009

Background Neuroblastic tumors (NT) are pediatric neoplasms with a heterogeneous genetic profile. They present genotypic alterations of prognostic value, the study of which is mandatory in designing therapeutic management. Tissue microarrays (TMA) from paraffin material allow the analysis of a large number of cases with minimal costs. The main purpose of the present study is to analyze specific genetic markers of neuroblastic tumors included in TMAs and determine their prognostic value. We compare the results obtained by different molecular techniques at different substrates to evaluate the feasibility of these assays. Procedure One hundred thirty-nine samples were included in four differen…

Diversity Arrays Technology (DArT) for Pan-genomic Evolutionary Studies of Non-model Organisms

2007

BackgroundHigh-throughput tools for pan-genomic study, especially the DNA microarray platform, have sparked a remarkable increase in data production and enabled a shift in the scale at which biological investigation is possible. The use of microarrays to examine evolutionary relationships and processes, however, is predominantly restricted to model or near-model organisms.Methodology/principal findingsThis study explores the utility of Diversity Arrays Technology (DArT) in evolutionary studies of non-model organisms. DArT is a hybridization-based genotyping method that uses microarray technology to identify and type DNA polymorphism. Theoretically applicable to any organism (even one for wh…

Cold tolerance and cold-induced modulation of gene expression in two Drosophila virilis group species with different distributions

2011

Abstract The importance of high and low temperature tolerance in adaptation to changing environmental conditions has evoked new interest in modulations in gene expression and metabolism linked with stress tolerance. We investigated the effects of rapid cold hardening and cold acclimatization on the chill coma recovery times of two Drosophila virilis group species, Drosophila montana and D. virilis, with different distributions and utilized a candidate gene approach to trace changes in their gene expression during and after the cold treatments. The study showed that cold acclimatization clearly decreases chill coma recovery times in both species, whereas rapid cold hardening did not have a s…

Transcriptome Fingerprint of Bovine 2-Cell Stage Blastomeres Is Directly Correlated with the Individual Developmental Competence of the Corresponding…

2012

To date, gene expression profiles of bovine preimplantation embryos have only been indirectly related to developmental potential due to the invasive nature of such procedures. This study sought to find a direct correlation between transcriptome fingerprint of blastomeres of bovine 2-cell stage embryos with developmental competence of the corresponding sister blastomeres. Isolated blastomeres were classified according to the sister blastomere's development into three groups: two groups displayed developmental incompetency, including those blastomeres whose corresponding sister blastomeres either stopped cleaving after separation (2CB) or were blocked after two additional cleavages before emb…

Classic bladder exstrophy: Frequent 22q11.21 duplications and definition of a 414 kb phenocritical region

2014

Background: Classic bladder exstrophy (CBE) is the most common form of the bladder exstrophy and epispadias complex. Previously, we and others have identified four patients with a duplication of 22q11.21 among a total of 96 unrelated CBE patients. Methods: Here, we investigated whether this chromosomal aberration was commonly associated with CBE/bladder exstrophy and epispadias complex in an extended case-control sample. Multiplex ligation-dependent probe amplification and microarray-based analysis were used to identify 22q11.21 duplications in 244 unrelated bladder exstrophy and epispadias complex patients (including 217 CBE patients) and 665 healthy controls. Results: New duplications of …