The mitogen-activated protein kinase (MAPK) p38alpha controls inflammatory responses and cell proliferation. Using mice carrying conditional p38alpha alleles, we investigated its function in postnatal development and tumorigenesis. When p38alpha is specifically deleted in the mouse embryo, fetuses develop to term but die shortly after birth, likely due to lung dysfunction. Fetal hematopoietic cells and embryonic fibroblasts deficient in p38alpha display increased proliferation, resulting from sustained activation of the c-Jun N-terminal kinase (JNK)/c-Jun pathway. Importantly, in chemical-induced liver cancer development, mice with liver-specific deletion of p38alpha show enhanced hepatocyte proliferation and tumor development that also correlates with JNK/c-Jun upregulation. Furthermore, increased proliferation of p38alpha-deficient hepatocytes and tumor cells is suppressed by inactivation of JNK or c-Jun. These results reveal a novel mechanism whereby p38alpha negatively regulates cell proliferation through antagonizing the JNK/c-Jun pathway in multiple cell types and in liver cancer development.
p38alpha suppresses normal and cancer cell proliferation by antagonizing the JNK-c-Jun pathway.
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View SamplesWe used high density oligonucleotide arrays to identify molecular correlates of genetically and clinically distinct subgroups of B-cell chronic lymphocytic leukemia (B-CLL). Gene expression profiling was used to profile the five most frequent genomic aberrations, namely deletions affecting chromosome bands 13q14, 11q22-q23, 17p13 and 6q21, and gains of genomic material affecting chromosome band 12q13. A strikingly high degree of correlation between loss or gain of genomic material and the amount of transcripts from the affected regions leads to the hypothesis of gene dosage as a significant pathogenic factor. Furthermore, the influence of the immunoglobulin variable heavy chain (VH) mutation status was determined. A clear distinction in the expression profiles of unmutated and mutated VH samples exists, which can be discovered using unsupervised learning methods. However, when samples were separated by gender, this separation could only be detected in samples from male patients.
Microarray gene expression profiling of B-cell chronic lymphocytic leukemia subgroups defined by genomic aberrations and VH mutation status.
No sample metadata fields
View SamplesPurpose: Seek for differential gene expression in vemurafenib-resistant A375 tumors vs. untreated controls to provide a rationale for resistance mechanism Methods: mRNA profiles of vemurafenib-resistant A375 tumors and untreated control tumors were generated by transcriptome sequencing of A375 melanoma bearing mice. Since our xenograft samples contain a mixture of human and mouse RNAs we mapped RNASeq reads against a hybrid human/mouse genome. We than removed reads of potential mouse origin by taking only reads that map uniquely to human chromosomes. On average 23% of reads were removed as potential mouse reads. We than took the remaining reads (on average 77% per sample) to determine the gene expression levels for each sample. Normalized expression levels of 5 resistant samples were compared to 4 untreated control samples to detect differnetially regulated genes which may contribute to vemurfenib resistance Results: Expression levels of several genes were consistently altered in all resistant samples. Expression of e.g. genes encoding SPRY2, SPRY4, DUSP6, CCND1, PIK3R3, FGFR1, EPHA4, MCL1, and IGF1R was down-regulated, whereas expression of PDGFC, VEGFC, ABCB9 and KITLG was increased. Conclusions: Our study reports several differentially expressed genes which may contribute to vemurafenib resistance in A375 tumor bearing mice Overall design: RNA sequencing of genes expressed in A375 tumors bearing mice treated with vemurafenib until in vivo resistance appeared vs. untreated A375 tumors
A Novel RAF Kinase Inhibitor with DFG-Out-Binding Mode: High Efficacy in BRAF-Mutant Tumor Xenograft Models in the Absence of Normal Tissue Hyperproliferation.
No sample metadata fields
View SamplesHistone deacetylase 1 (HDAC1) is an enzyme that promotes deacetylation of acetylated lysine residues in histones and other proteins. Histone acetylation is often associated with gene activation and expression. Los of HDAC1 leads to severe problems in development and proliferation. Moreover, it seems to be the major histone deacetylase in mouse embryonic stem cells.
Negative and positive regulation of gene expression by mouse histone deacetylase 1.
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Efficacy of the highly selective focal adhesion kinase inhibitor BI 853520 in adenocarcinoma xenograft models is linked to a mesenchymal tumor phenotype.
Cell line
View SamplesmRNA expression profiling of untreated CDX samples and correlation with sensitivity data derived from treatments with BI 853520.
Efficacy of the highly selective focal adhesion kinase inhibitor BI 853520 in adenocarcinoma xenograft models is linked to a mesenchymal tumor phenotype.
Cell line
View SamplesGenome-wide association studies (GWAS) have identified dozens of genomic loci, whose single nucleotide polymorphisms (SNPs) predispose to prostate cancer (PCa). However, the biological functions of these common genetic variants and the mechanisms to increase disease risk are largely unknown. We integrated chromatin-IP coupled sequencing (ChIP-seq) and microarray expression profiling in the TMPRSS2-ERG gene rearrangement positive DuCaP cell model with the NHGRI GWAS PCa risk SNPs catalog, in an attempt to identify disease susceptibility SNPs localized within functional androgen receptor binding sites (ARBSs). Among the 48 GWAS index SNPs and 2,702 linked SNPs defined by the 1000G project 104 were found to be localized in the AR ChIP-seq peaks. Of these risk SNPs, rs11891426 T/G in the 7th intron of its host gene melanophilin (MLPH) was found located within a putative auxiliary ARE motif, which we found enriched in the neighborhood of canonical ARE motifs. Exchange of T to G attenuated the transcriptional activity of the MLPH-ARBS in a reporter gene assay. The expression of MLPH protein in tissue samples from prostate cancer patients was significantly lower in those with the G compared to the T allele. Moreover, a significant positive correlation of AR and MLPH protein expression levels was also confirmed in tissue samples. These results unravel a hidden link between AR and a functional PCa risk SNP rs11891426, whose allele alteration affects androgen regulation of its host gene MLPH. This study shows the power of integrative studies to pin down functional risk SNPs and justifies further investigations.
Putative Prostate Cancer Risk SNP in an Androgen Receptor-Binding Site of the Melanophilin Gene Illustrates Enrichment of Risk SNPs in Androgen Receptor Target Sites.
Cell line, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Position-dependent alternative splicing activity revealed by global profiling of alternative splicing events regulated by PTB.
Cell line
View SamplesTo gain global insights into the role of the well-known repressive splicing regulator PTB we analyzed the consequences of PTB knockdown in HeLa cells using high-density oliogonucleotide splice-sensitive microarrays. The major class of identified PTB-regulated splicing event was PTB-repressed cassette exons, but there was also a substantial number of PTB-activated splicing events. PTB repressed and activated exons showed a distinct arrangement of motifs with pyrimidine-rich motif enrichment within and upstream of repressed exons, but downstream of activated exons. The N-terminal half of PTB was sufficient to activate splicing when recruited downstream of a PTB-activated exon. Moreover, insertion of an upstream pyrimidine tract was sufficient to convert a PTBactivated to a PTB-repressed exon. Our results demonstrate that PTB, an archetypal splicing repressor, has variable splicing activity that predictably depends upon its binding location with respect to target exons.
Position-dependent alternative splicing activity revealed by global profiling of alternative splicing events regulated by PTB.
Cell line
View SamplesTranscript profiling analysis of csn4-1 light grown mutant seedlings compared to wild type using Arabidopsis ATH1 GeneChip array
Characterization of the VIER F-BOX PROTEINE genes from Arabidopsis reveals their importance for plant growth and development.
No sample metadata fields
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