Mice lacking the beta 2 subunit (Chrnb2) of the neuronal nicotinic acetylcholine receptor display altered retinal waves and disorganized projections of the retinal ganglion cells to the lateral geniculate nucleus (LGN). mRNA populations from retinas and LGN from Chrnb2-/-and wild type (C57BL/6J) mice were compared at 4 days postnatal, when RGC segregation to the LGN begins in WT mice. Retinal mRNAs were also compared at adulthood.
Mouse mutants for the nicotinic acetylcholine receptor ß2 subunit display changes in cell adhesion and neurodegeneration response genes.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Truncating PREX2 mutations activate its GEF activity and alter gene expression regulation in NRAS-mutant melanoma.
Specimen part
View SamplesPREX2 truncating mutations occur in melanoma. We used microarray based gene expression profiling to compare expression patterns between xenografts harboring control GFP, wt PREX2 or various human relevant PREX2 mutants
Truncating PREX2 mutations activate its GEF activity and alter gene expression regulation in NRAS-mutant melanoma.
Specimen part
View SamplesPREX2 truncating mutations occur in melanoma. We used microarray based gene expression profiling to compare expression patterns between cells harboring Suv420h1 knockout and PREX2 mutant expressing
Truncating PREX2 mutations activate its GEF activity and alter gene expression regulation in NRAS-mutant melanoma.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenetic mechanisms underlying arsenic-associated lung carcinogenesis.
Specimen part, Disease, Treatment, Time
View SamplesArsenic is methylated during its metabolism, thereby depleting the intracellular methyl donor S-adenosyl-methionine, which may lead to disturbances in DNA methylation patterns which could lead to altered gene expression
Epigenetic mechanisms underlying arsenic-associated lung carcinogenesis.
Specimen part, Treatment, Time
View SamplesAlmost a quarter of pediatric patients with Acute Lymphoblastic Leukemia (ALL) suffer from relapses. The biological mechanisms underlying therapy response and development of relapses have remained unclear. In an attempt to better understand this phenomenon, we have analyzed 41 matched diagnosis relapse pairs of ALL patients using genomewide expression arrays (82 arrays) on purified leukemic cells. In roughly half of the patients very few differences between diagnosis and relapse samples were found (stable group), suggesting that mostly extra-leukemic factors (e.g., drug distribution, drug metabolism, compliance) contributed to the relapse. Therefore, we focused our further analysis on 20 samples with clear differences in gene expression (skewed group), reasoning that these would allow us to better study the biological mechanisms underlying relapsed ALL. After finding the differences between diagnosis and relapse pairs in this group, we identified four major gene clusters corresponding to several pathways associated with changes in cell cycle, DNA replication, recombination and repair, as well as B cell developmental genes. We also identified cancer genes commonly associated with colon carcinomas and ubiquitination to be upregulated in relapsed ALL. Thus, about half of relapses are due to selection or emergence of a clone with deregulated expression of a genes involved in pathways that regulate B cell signaling, development, cell cycle, cellular division and replication.
Genome-wide expression analysis of paired diagnosis-relapse samples in ALL indicates involvement of pathways related to DNA replication, cell cycle and DNA repair, independent of immune phenotype.
Sex, Specimen part, Disease
View SamplesBackground and Purpose—Analyzing genes involved in development and rupture of intracranial aneurysms can enhance knowledge about the pathogenesis of aneurysms, and identify new treatment strategies. We compared gene expression between ruptured and unruptured aneurysms and control intracranial arteries. Methods—We determined expression levels with RNA sequencing. Applying a multivariate negative binomial model, we identified genes that were differentially expressed between 44 aneurysms and 16 control arteries, and between 22 ruptured and 21 unruptured aneurysms. The differential expression of 8 relevant and highly significant genes was validated using digital polymerase chain reaction. Pathway analysis was used to identify enriched pathways. We also analyzed genes with an extreme pattern of differential expression: only expressed in 1 condition without any expression in the other. Results—We found 229 differentially expressed genes in aneurysms versus controls and 1489 in ruptured versus unruptured aneurysms. The differential expression of all 8 genes selected for digital polymerase chain reaction validation was confirmed. Extracellular matrix pathways were enriched in aneurysms versus controls, whereas pathways involved in immune response and the lysosome pathway were enriched in ruptured versus unruptured aneurysms. Immunoglobulin genes were expressed in aneurysms, but showed no expression in controls. Conclusions—For rupture of intracranial aneurysms, we identified the lysosome pathway as a new pathway and found further evidence for the role of the immune response. Our results also point toward a role for immunoglobulins in the pathogenesis of aneurysms. Immune-modifying drugs are, therefore, interesting candidate treatment strategies in the prevention of aneurysm development and rupture. Overall design: RNA sequencing of 44 intracranial aneurysm samples (including 21 unruptured, 22 ruptured and 1 undetermined) and 16 control samples of the intracranial cortical artery
RNA Sequencing Analysis of Intracranial Aneurysm Walls Reveals Involvement of Lysosomes and Immunoglobulins in Rupture.
Sex, Age, Subject
View SamplesColon cancer is a major cause of cancer deaths in Western countries and is associated with diets high in red meat. Heme, the iron-porphyrin pigment of red meat, induces cytotoxicity of gut contents which injures surface cells leading to compensatory hyperproliferation of crypt cells. This hyperproliferation results in epithelial hyperplasia which increases the risk of colon cancer. In humans, a high red-meat diet increases Bacteroides spp in feces. Therefore, we simultaneously investigated the effects of dietary heme on colonic microbiota and on the host mucosa of mice. Whole genome microarrays showed that heme injured the colonic surface epithelium and induced hyperproliferation by changing the surface to crypt signaling. Using 16S rRNA phylogenetic microarrays, we investigated whether bacteria play a role in this changed signaling. Heme increased Bacteroidetes and decreased Firmicutes in colonic contents. This shift was most likely caused by a selective susceptibility of Gram-positive bacteria to heme cytotoxic fecal water, which is not observed for Gram-negative bacteria, allowing expansion of the Gram-negative community. The increased amount of Gram-negative bacteria most probably increased LPS exposure to colonocytes, however, there is no appreciable immune response detected in the heme-fed mice. There was no functional change in the sensing of the bacteria by the mucosa, as changes in inflammation pathways and Toll- like receptor signaling were not detected. This unaltered host-microbe cross-talk indicates that the changes in microbiota did not play a causal role in the observed hyperproliferation and hyperplasia.
Dietary heme alters microbiota and mucosa of mouse colon without functional changes in host-microbe cross-talk.
Sex, Age, Specimen part
View SamplesPreviously, we showed that dietary heme injured the colonic surface epithelium and induced hyperproliferation by changing the surface to crypt signaling. In this study we investigated whether bacteria play a role in this changed signaling. Dietary heme increased the Bacteroidetes and decreased the Firmicutes in colonic content. This shift was caused by a selective susceptibility of Gram-positive bacteria to the heme cytotoxic fecal waters, which is not observed for Gram-negative bacteria allowing expansion of the Gram-negative community. The increased amount of Gram-negative bacteria increased LPS exposure to colonocytes, however, there is no appreciable immune response detected in the heme-fed mice. There were no signs of sensing of the bacteria by the mucosa, as changes in TLR signaling were not present. This lack of microbe-host cross talk indicated that the changes in microbiota do not play a causal role in the heme-induced hyperproliferation.
Dietary heme alters microbiota and mucosa of mouse colon without functional changes in host-microbe cross-talk.
Sex, Age, Specimen part, Treatment
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