To investigate potential differences between strong and weak oscillators at the gene expression level we carried out a transcriptome analysis for each cell line. Our results indicate that phenotypic circadian clock differences are reflected by gene expression differences both in genes of the core network, but also in additional genes not directly associated with circadian clock functions.
Ras-mediated deregulation of the circadian clock in cancer.
Specimen part, Cell line, Time
View SamplesPhosphate (Pi) deficiency triggers the differential expression of a large set of genes, which communally adapt the plant to low Pi bioavailability.
Coexpression-based clustering of Arabidopsis root genes predicts functional modules in early phosphate deficiency signaling.
Specimen part
View SamplesThe CHLD and CHLM genes encode proteins involved in tetrapyrrole biosynthesis pathway. It was proposed that intermediates like magnesium protoporphyrin might play a role in retrograde plastid-to-nucleus signaling. In the present work we provide evidence that altered enzymes activity of the tetrapyrrole biosynthesis pathway are causing changes in gene expression of over 200 nuclear genes.
No associated publication
Age, Specimen part
View Samples5-aminolevulinic acid (ALA) is the common precursor of all biological synthezised tetrapyrroles. Inhibition of ALA synthesis results in decreased amounts of chlorophylls, heme, siroheme and phytochrome. It was previously shown that 4 out of 5 Arabidopsis mutants uncoupling nuclear gene expression from the physiological state of the chloroplast are affected in plant tetrapyrrole biosynthesis. It is common to all four mutants to show a reduced ALA formation.
Evidence for a Contribution of ALA Synthesis to Plastid-To-Nucleus Signaling.
Age, Specimen part
View SamplesA characteristic feature of anaplastic large cell lymphoma (ALCL) is the significant reduction of the T-cell expression program despite its T-cell origin, a finding very similar to the loss of B-cell identity of classical Hodgkin lymphoma (cHL). Previously we demonstrated that epigenetic mechanisms are active in cHL to induce this peculiar phenotype. The results show that combined DNA demethylation and histone acetylation of T-cell lines induce an almost complete extinction of the T-cell phenotype, including the down-regulation of essential T-cell receptor signalling pathway genes such as CD3, LCK and ZAP70, as well as an up-regulation of ALCL-characteristic genes. In contrast, combined DNA demethylation and histone acetylation of ALCL cells is not able to reconstitute their T-cell phenotype. This clearly demonstrates that similar epigenetic mechanisms are active in ALCL and cHL which are responsible for the extinction of their cell type characteristic phenotype.
Histone acetylation and DNA demethylation of T cells result in an anaplastic large cell lymphoma-like phenotype.
Specimen part, Cell line, Treatment
View SamplesHead and neck cancer is a hetergeneous disease. Based on previoulsy defined molecular subtypes we associated gene expression with response to different compounds. We used microarry gene expression for molecular subtyping
Basal subtype is predictive for response to cetuximab treatment in patient-derived xenografts of squamous cell head and neck cancer.
No sample metadata fields
View SamplesElevated levels of adsorbable organic bromine compounds (AOBr) have been detected in German lakes, and cyanobacteria like Microcystis, which are known for the synthesis of microcystins, are one of the main producers of natural organobromines. However, very little is known about how environmental realistic concentrations of organobromines impact invertebrates. Here, the nematode C. elegans was exposed to AOBr-containing surface water samples and to a Microcystis aeruginosa enriched batch culture (MC-BA) and compared to single organobromines and microcystin-LR exposures. Stimulatory effects were observed in certain life trait variables, which were particularly pronounced in nematodes exposed to MC-BA. A whole genome DNA-microarray revealed that MC-BA led to the differential expression of more than 2000 genes, many of which are known to be involved in metabolic, neurologic, and morphologic processes. Moreover, the up-regulation of cyp- and the down-regulation of abu-genes suggested the presence of chronic stress. However, the nematodes were not marked by negative phenotypic responses. The observed difference in MC-BA and microcystin-LR (which impacted lifespan, growth and reproduction) exposed nematodes was hypothesized to be likely due to other compounds within the batch culture. Most likely the exposure to low concentrations of organobromines appears to buffer the effects of toxic substances, like microcystin-LR.
No associated publication
No sample metadata fields
View SamplesAlternative mRNA splicing represents an effective mechanism of regulating gene function and is a key element to increase the coding capacity of the human genome. Today, an increasing number of reports illustrates that aberrant splicing events are common and functionally important for cancer development. However, more comprehensive analyses are warranted to get novel insights into the biology underlying malignancies like e.g. acute myeloid leukemia (AML). Here, we performed a genome-wide screening of splicing events in AML using an exon microarray platform. We analyzed complex karyotype and core binding factor (CBF) AML cases (n=64) in order to evaluate the ability to detect alternative splicing events distinguishing distinct leukemia subgroups. Testing different commercial and open source software tools to compare the respective AML subgroups, we could identify a large number of potentially alternatively spliced transcripts with a certain overlap of the different approaches. Selected candidates were further investigated by PCR and sequence analysis: out of 24 candidate genes studied, we could confirm alternative splice forms in 8 genes of potential pathogenic relevance, such as PRMT1 regulating transcription through histone methylation and participating in DNA damage response, and PTPN6, which encodes for a negative regulator of cell cycle control and apoptosis. In summary, this first large Exon microarray based study demonstrates that transcriptome splicing analysis in AML is feasible but challenging, in particular with regard to the currently available software solutions. Nevertheless, our results show that alternatively spliced candidate genes can be detected, and we provide a guide how to approach such analyses.
A robust estimation of exon expression to identify alternative spliced genes applied to human tissues and cancer samples.
Specimen part, Disease, Disease stage
View SamplesThis SuperSeries is composed of the SubSeries listed below.
An immediate-late gene expression module decodes ERK signal duration.
Specimen part, Cell line
View SamplesPurpose: In childhood acute lymphoblastic leukemia (ALL), approximately 25% of patients suffer from relapse. In recurrent disease, despite intensified therapy, overall cure rates of 40% remain unsatisfactory and survival rates are particularly poor in certain subgroups. The probability of long-term survival after relapse is predicted from well-established prognostic factors, i. e. time and site of relapse, immunophenotype and minimal residual disease. However, the underlying biological determinants of these prognostic factors remain poorly understood.
No associated publication
Sex
View Samples