This SuperSeries is composed of the SubSeries listed below.
Specific genomic and transcriptomic aberrations in tumors induced by partial hepatectomy of a chronically inflamed murine liver.
Sex, Specimen part, Treatment
View SamplesSurgical resection is the preferred treatment for Hepatocellular carcinoma; however, it induces tumor recurrence. Our objective was to understand the molecular mechanisms linking liver regeneration under chronic-inflammation to tumorigenesis. Mdr2-knockout mice, a model of inflammation-associated cancer, underwent partial-hepatectomy which led to enhanced hepatocarcinogenesis. Yet, liver regeneration in these mice was severely attenuated. We demonstrate the activation of the DNA damage response machinery and altered genomic instability during early liver inflammatory stages resulting in hepatocyte apoptosis and cell-cycle arrest, and suggest their involvement in tumor recurrence subsequent to partial hepatectomy. We propose that under the regenerative proliferative stress induced by liver resection, the genomic unstable hepatocytes generated during chronic-inflammation, escape apoptosis and reenter the cell-cycle, triggering the enhanced tumorigenesis
Accelerated carcinogenesis following liver regeneration is associated with chronic inflammation-induced double-strand DNA breaks.
No sample metadata fields
View SamplesBackground & Aims. Resection of hepatocellular carcinoma (HCC) tumors by partial hepatectomy (PHx) is associated with promoting hepatocarcinogenesis. We have previously reported that PHx promotes hepatocarcinogenesis in the Mdr2-knockout (Mdr2-KO) mouse, a model for inflammation-mediated HCC. Now, we explored the molecular mechanisms underlying the tumor-promoting effect of PHx in these mice. Methods. Using microarrays-based techniques, we compared genomic and transcriptomic profiles of HCC tumors developing in the Mdr2-KO mice either spontaneously or following PHx. Results. PHx accelerated HCC development in these mice by four months. PHx-induced tumors had only amplifications affecting multiple chromosomes and locating mainly near the acrocentric centromeres of murine chromosomes. Four different chromosomal regions were amplified each in at least three tumors. All tumors of untreated mice had chromosomal aberrations, including both deletions and amplifications. Comparison of gene expression profiles revealed a significantly enriched expression of oncogenes, chromosomal instability markers and E2F1 targets in the post-PHx compared to spontaneous tumors. Both tumor groups shared the same frequent amplification at chromosome 18. Here, we demonstrated that one of the regulatory genes encoded by this amplified region, Crem, was over-expressed in the nuclei of murine and human HCC cells in vivo, and that it stimulated proliferation of human HCC cells in vitro. Conclusions: PHx of a chronically inflamed liver directed tumor development to a discrete pathway characterized by amplification of specific chromosomal regions and expression of specific tumor-promoting genes. Crem is a new candidate HCC oncogene frequently amplified in this model and frequently over-expressed in human HCC.
Specific genomic and transcriptomic aberrations in tumors induced by partial hepatectomy of a chronically inflamed murine liver.
Specimen part, Treatment
View SamplesHeterochromatic position effect variegation (PEV) is the epigenetic disruption of genes expression near the new-formed eu-heterochromatic border. We characterized the inversion In(2)A4, demonstrating cis-acting PEV as well as trans-inactivation of the reporter transgenes on the opposite normal chromosome in combination with the inversion. Euchromatic breakpoint of In(2)A4 inversion was localized at 105 bp region (chr2L:21182214-21182318) of the second exon of the Mcm10 gene, the heterochromatic breakpoint is located at the block of dodecasatellite in 2L pericentromeric heterochromatin. In order to check the effects of heterochromatin on neighbor euchromatic genes and estimate the distance of inactivation spreading, we performed RNA-seq analysis of genes expression in larvae and adults females of genotypes A12/A12 (control) and In(2)A4/In(2)A4. Cis-influence of heterochromatin in the inversion causes not only repression, but also activation of genes, and the effects of heterochromatin are different at different developmental stages. Cis-actions affect only a few genes located near the heterochromatin Overall design: Comparison of genes expression in wild type and demonstrating PEV larvae and adults in two repeats each
Trans-inactivation: Repression in a wrong place.
Sex, Subject
View SamplesThe cytotoxic drug edelfosine is a synthetic analog of 2-lysophosphatidylcholine. Edelfosine is incorporated by highly proliferating cells, e.g. activated immune cells. It is unknown if the described mechanisms for edelfosine action attained by in vitro approaches exclusively contribute to the observed EAE-amelioration or if edelfosine may exert additional, probably more general and possibly immunoablative effects within the setting of autoimmunity.
The orally available, synthetic ether lipid edelfosine inhibits T cell proliferation and induces a type I interferon response.
Specimen part, Treatment
View SamplesPIWI interacting RNAs (piRNAs) provide defense against transposable element (TE) expansion in the germline of metazoans. piRNAs are processed from the transcripts encoded by specialized heterochromatic clusters enriched in damaged copies of transposons. How these regions are recognized as a source of piRNAs is still elusive. The aim of this study is to determine how transgenes that contain a fragment of the LINE-like I transposon lead to an acquired TE resistance in Drosophila. We show that such transgenes, being inserted in unique euchromatic regions which normally do not produce small RNAs, become de novo bidirectional piRNA clusters that silence I-element activity in the germline. Strikingly, small RNAs of both polarities are generated from the entire transgene and flanking genomic sequences — not only from the transposon fragment. Chromatin immunoprecipitation analysis shows that in ovaries the trimethylated histone 3 lysine 9 (H3K9me3) mark associates with transgenes producing piRNAs. We show that transgene-derived hsp70 piRNAs stimulate in trans cleavage of cognate endogenous transcripts with subsequent processing of the non-homologous parts of these transcripts into piRNAs. Overall design: The fractions of small RNAs (19-29 nt) from ovaries of wild type and 11 transgenic lines of Drosophila melanogaster were sequenced using Illumina HiSeq 2000.
De novo piRNA cluster formation in the Drosophila germ line triggered by transgenes containing a transcribed transposon fragment.
Specimen part, Subject
View SamplesWe identified DNAPK as one of the major proteins that physically interact with Autoimmune regulator (Aire). To establish physiological significance of DNAPK in Aire-driven expression of PTA genes in MECs, we utilized BM-reconstituted SCID mice (which express non functional DNAPK in their MECs) and RAG1 null mouse as a control.
Aire's partners in the molecular control of immunological tolerance.
Specimen part
View SamplesLong-lasting activation of T cells requires up-regulation of many genes, for example of transcription factors, cytoskeletal proteins and cell surface proteins encluding ion channels. An increase of ion channel density at the cell surface reflects the needs to manage increased Ca2+ influx into the activated T cell. Using oligonucleotide-based arrays we have surveyed changes in ion channel mRNA expression that occur upon T cell activation. We used Affymetrix Analysis to confirmate our data achieved by self-designed glass array analysis.
A truncation variant of the cation channel P2RX5 is upregulated during T cell activation.
No sample metadata fields
View SamplesGlobal gene expression studies were performed to determine whether the granulocytic-like MDSC populations from G-CSF treated mice resembled those of tumor-bearing (TB) mice more so than those of the non-tumor-bearing control (i.e., WT) at a molecular level.
Tumor-derived G-CSF facilitates neoplastic growth through a granulocytic myeloid-derived suppressor cell-dependent mechanism.
Sex, Specimen part
View SamplesTo analyze the impact of Aire on gene expression profile in a model cell line, we used 293T cells and transfected them either with an Aire expression plasmid pCMV-Aire (where mAire is driven by CMV promoter) or with a control plasmid pCMV2B.
Aire's partners in the molecular control of immunological tolerance.
Specimen part
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