Recurrent somatic hotspot mutations of DICER1 appear to be clustered around each of four critical metal binding residues in the RNase IIIB domain of DICER1. This domain is responsible for cleavage of the 3 end of the 5p-miRNA strand of a pre-mRNA hairpin. To investigate the effects of these cancer-associated hotspot mutations we engineered mouse Dicer1-deficient ES cells to express wild-type and an allelic series of the mutant human DICER1 variants. Global miRNA and mRNA profiles from cells carrying the metal binding site mutations were compared to each other and wild-type human DICER1. The miRNA and mRNA profiles generated through the expression of the hotspot mutations were virtually identical, and the DICER1 hotspot mutation carrying cells were distinct from both wild-type and Dicer1-deficient cells. Further, miRNA profiles showed mutant DICER1 results in a dramatic loss in processing of mature 5p-miRNA strands but were still able to create 3p-strand miRNAs. Messenger-RNA profile changes were consistent with the loss of 5p-strand miRNAs and showed enriched expression for predicted targets of the lost 5p derived miRNAs. We therefore conclude that cancer-associated somatic hotspot mutations of DICER1, affecting any one of four metal binding residues in the RNase IIIB domain, are functionally equivalent with respect to miRNA-processing and are hypomorphic alleles, yielding a global loss in processing of mature 5p-strand miRNA. We further propose that this resulting 3p-strand bias in mature miRNA expression likely underpins the oncogenic potential of these hotspot mutations.
Cancer-associated somatic DICER1 hotspot mutations cause defective miRNA processing and reverse-strand expression bias to predominantly mature 3p strands through loss of 5p strand cleavage.
Specimen part
View SamplesS. aureus biofilms are associated with the organism's ability to cause disease. Biofilm associated bacteria must cope with the host's innate immune system.
Global transcriptome analysis of Staphylococcus aureus biofilms in response to innate immune cells.
No sample metadata fields
View SamplesExpression profile of 30 LMP tumours and 60 Serous tumours were compared to identify the biolgical pathways specific to these groups. Genotyping was done to identify the mutations potentially causing these phenotypes
Mutation of ERBB2 provides a novel alternative mechanism for the ubiquitous activation of RAS-MAPK in ovarian serous low malignant potential tumors.
No sample metadata fields
View SamplesMagnaporthe oryzae causes rice blast, the most devastating foliar fungal disease of cultivated rice. During disease development the fungus simultaneously maintains both biotrophic and necrotrophic growth corresponding to a hemi-biotrophic life style. The ability of M. oryzae to also colonize roots and subsequently develop blast symptoms on aerial tissue has been recognized. The fungal root infection strategy and the respective host responses are currently unknown. Global temporal expression analysis suggested a purely biotrophic infection process reflected by the rapid induction of defense response-associated genes at the early stage of root invasion and subsequent repression coinciding with the onset of intracellular fungal growth. The same group of down-regulated defense genes was increasingly induced upon leaf infection by M. oryzae where symptom development occurs shortly post tissue penetration. Our molecular analysis therefore demonstrates the existence of fundamentally different tissue-specific fungal infection strategies and provides the basis for enhancing our understanding of the pathogen life style.
Tissue-adapted invasion strategies of the rice blast fungus Magnaporthe oryzae.
Specimen part
View SamplesObjective: Physical exercise and vitamin E are considered effective treatments of nonalcoholic fatty liver and other metabolic diseases. However, vitamin E has also been shown to interfere with the adaptation to exercise training, in particular for the skeletal muscle. Here, we studied the hypothesis that vitamin E also interferes with the metabolic adaptation of the liver to acute exercise.
A Vitamin E-Enriched Antioxidant Diet Interferes with the Acute Adaptation of the Liver to Physical Exercise in Mice.
Sex, Specimen part
View SamplesEmbryonic mouse brain development involves a sequential differentiation of multipotent progenitor cells into neurons and glia. Using microarrays and large 2-D electrophoresis, we investigated the transcriptome and proteome of mouse brains at embryonic days 9.5, 11.5 and 13.5. During this developmental period, neural progenitor cells shift from proliferation to neuronal differentiation. As expected, we detected numerous expression changes between the time points investigated but interestingly, the rate of alteration was about 10% to 13% of all proteins and mRNAs during every two days of development. Furthermore, up- and downregulation was balanced. This was confirmed for two additional stages of development, embryonic day 16 and 18. We hypothesize that during embryonic development, the rate of protein expression alteration is rather constant due to a limitation of cellular resources such as energy, space and free water. The similar complexity found at the transcriptome and proteome level at all stages suggests, that changes in relative concentration of gene products rather than an increased number of gene products dominate throughout cellular differentiation. We found that metabolism and cell cycle related gene products were downregulated in expression when precursor cells switched from proliferation to neuronal differentiation (day 9.5 to 11.5), whereas neuron specific gene products were upregulated. A detailed analysis revealed their implication in differentiation related processes such as rearrangement of the actin cytoskeleton as well as Notch and Wnt signaling pathways.
Transcriptome and proteome analysis of early embryonic mouse brain development.
No sample metadata fields
View SamplesUpon induction of DNA damage Arabidopsis thaliana plants initiate a transcriptional response program governed by signalling cascades which are activated by the ATM and ATR kinases
GMI1, a structural-maintenance-of-chromosomes-hinge domain-containing protein, is involved in somatic homologous recombination in Arabidopsis.
Specimen part
View SamplesL-type voltage gated Ca channels play a critical role in E-C coupling in cardiac muscle. alpha1C is associated with beta auxiliary subunits (b1-b4), which regulate cardiac Ca channel gating properties. Here we report a preliminary exploratory study suggesting a novel role of beta4 subunit in heart. We observed that overexpression of beta4 subunit increases the expression of a wide variety of endogenous genes related to antiviral activity. This includes genes in the downstream signalling of RIG-1 pathway such as RIG-1, Irf7 and Ifitm3. The increase expression of these factors may have an antiviral protective role against infection. Overall design: Examination of an overall differential expression by the beta4 subunit
The β<sub>4</sub> subunit of Ca<sub>v</sub>1.2 channels is required for an optimal interferon response in cardiac muscle cells.
Specimen part, Cell line, Subject
View SamplesWe used unsupervised hierarchical clustering to analyse expression in primary ovarian tumors and associated abdominal deposits. GeneGo pathway analysis of differentially expressed genes between primary tumors and deposits revealed 4 of the top 10 pathways related to cytoskeleton remodeling and cell adhesion.
LRP1B deletion in high-grade serous ovarian cancers is associated with acquired chemotherapy resistance to liposomal doxorubicin.
Sex, Specimen part, Subject
View SamplesMuscle contraction during exercise is the major stimulus for the release of peptides and proteins (myokines) that are supposed to take part in the benefical adaptation to exercise. We hypothesize that application of an in vitro exercise stimulus as electric pulse stimulation (EPS) to human myotubes enables the investigation of the human muscle secretome in a clearly defined model. We applied EPS for 24 h to primary human myotubes and studied the whole genome-wide transcriptional response and as well as the release of candidate myokines. We observed 183 differentially regulated transcripts with fold-changes > 1.3. The transcriptional response resembles several properties of the in vivo situation in the skeletal muscle after endurance exercise, namely significant enrichment of pathways associated with interleukin and chemokine signaling, lipid metabolism, and anti-oxidant defense; notably without increased release of creatin kinase.
Cytokine response of primary human myotubes in an in vitro exercise model.
Sex, Specimen part, Subject
View Samples