Microgravity as well as chronic muscle disuse are two causes of low back pain originated at least in part from paraspinal muscle deconditioning. At present no study investigated the complexity of the molecular changes in human or mouse paraspinal muscles exposed to microgravity. The aim of this study was to evaluate longissimus dorsi and tongue (as a new potential in-flight negative control) adaptation to microgravity at global gene expression level. C57BL/N6 male mice were flown aboard the BION-M1 biosatellite for 30 days (BF) or housed in a replicate flight habitat on ground (BG). . Global gene expression analysis identified 89 transcripts differentially regulated in longissimus dorsi of BF vs. BG mice (False Discovery Rrate < 0,05 and fold change < -2 and > +2), while only a small number of genes were found differentially regulated in tongue muscle ( BF vs. BG = 27 genes).
Microgravity-Induced Transcriptome Adaptation in Mouse Paraspinal <i>longissimus dorsi</i> Muscle Highlights Insulin Resistance-Linked Genes.
Specimen part
View SamplesMicrogravity exposure as well as chronic muscle disuse are two of the main causes of physiological adaptive skeletal muscle atrophy in humans and murine animals in physiological condition. The aim of this study was to investigate, at both morphological and global gene expression level, skeletal muscle adaptation to microgravity in mouse soleus and extensor digitorum longus (EDL). Adult male mice C57BL/N6 were flown aboard the BION-M1 biosatellite for 30 days on orbit (BF) or housed in a replicate flight habitat on Earth (BG) as reference flight control.
Gene Expression Profiling in Slow-Type Calf Soleus Muscle of 30 Days Space-Flown Mice.
Sex, Specimen part
View SamplesThe ubiquitin proteasome system (UPS) is known to possess important regulatory functions in the immune response. To gain a better and first comprehensive insight into the mechanisms underlying the conversion of immature to mature DC in terms of the expression of UPS related genes, we undertook a comparative gene expression profiling during DC maturation in response to four different prototypic maturation stimuli.
Maturation of human dendritic cells is accompanied by functional remodelling of the ubiquitin-proteasome system.
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View SamplesThe ubiquitin proteasome system (UPS) is known to possess important regulatory functions in the immune response. To gain a better and first comprehensive insight into the mechanisms of remodelling of UPS related gene expression inresponse to interferon-gamma, we undertook a comparative gene expression profiling during interferon-gamma stimulation at very early time points.
Immunoproteasomes preserve protein homeostasis upon interferon-induced oxidative stress.
Specimen part, Time
View SamplesCoordinated regulation of the ubiquitin-proteasome system is crucial for the cell to adjust its protein degradation capacity to changing proteolytic requirements. The transcription factor TCF11 has been identified as a regulator for 26S-proteasome formation in human cells to compensate for reduced proteolytic activity. To expand the current knowledge of other UPS-related TCF11 target genes in response to epoxomicin, we performed microarray analyses of cells exposed to epoxomicin and with or without depletion of TCF11.
Proteasomal degradation is transcriptionally controlled by TCF11 via an ERAD-dependent feedback loop.
Specimen part
View SamplesOvarian carcinoma has the highest mortality rate among gynecological malignancies. In this project, we investigated the hypothesis that molecular markers are able to predict outcome of ovarian cancer independently of classical clinical predictors, and that these molecular markers can be validated using independent data sets. We applied a semi-supervised method for prediction of patient survival. Microarrays from a cohort of 80 ovarian carcinomas (TOC cohort) were used for the development of a predictive model, which was then evaluated in an entirely independent cohort of 118 carcinomas (Duke cohort). A 300 gene ovarian prognostic index (OPI) was generated and validated in a leave-one-out approach in the TOC cohort (Kaplan-Meier analysis, p=0.0087). In a second validation step the prognostic power of the OPI was confirmed in an independent data set (Duke cohort, p=0.0063). In multivariate analysis, the OPI was independent of the postoperative residual tumour, the main clinico-pathological prognostic parameter with an adjusted hazard ratio of 6.4 (TOC cohort, CI 1.8 23.5, p=0.0049) and 1.9 (Duke cohort, CI 1.2 3.0, p=0.0068). We constructed a combined score of molecular data (OPI) and clinical parameters (residual tumour), which was able to define patient groups with highly significant differences in survival. The integrated analysis of gene expression data as well as residual tumour can be used for optimised assessment of prognosis. As traditional treatment options are limited, this analysis may be able to optimise clinical management and to identify those patients that would be candidates for new therapeutic strategies.
A prognostic gene expression index in ovarian cancer - validation across different independent data sets.
Specimen part, Disease stage
View SamplesThe routine workflow for invasive cancer diagnostics is based on biopsy processing by formalin fixation and subsequent paraffin embedding. Formalin-fixed paraffin-embedded (FFPE) tissue samples are easy to handle, stable and particularly suitable for morphologic evaluation, immunohistochemistry and in situ hybridization. However, it has become a paradigm that these samples cannot be used for genome-wide expression analysis with microarrays. To oppose this view, we present a pilot microarray study using FFPE core needle biopsies from breast cancers as RNA source. We found that microarray probes interrogating sequences near the poly-A-tail of the transcribed genes were well suitable to measure RNA levels in FFPE core needle biopsies. For the ER and the HER2 gene, we observed strong correlations between RNA levels measured in these probe sets and protein expression determined by immunohistochemistry (p = 0.000003 and p = 0.0022). Further, we have identified a signature of 364 genes that correlated with ER protein status and a signature of 528 genes that correlated with HER2 protein status. Many of these genes (ER: 60%) could be confirmed by analysis of an independent publicly available data set. Finally, a hierarchical clustering of the biopsies with respect to three recently reported gene expression grade signatures resulted in widely stable low and high expression grade clusters that correlated with the pathological tumor grade. These findings support the notion that clinically relevant information can be gained from microarray based gene expression profiling of FFPE cancer biopsies. This opens new opportunities for the integration of gene expression analysis into the workflow of invasive cancer diagnostics as well as translational research in the setting of clinical studies.
Genome-wide gene expression profiling of formalin-fixed paraffin-embedded breast cancer core biopsies using microarrays.
Disease stage
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 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
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