We expressed a constitutively active mutant of MEK5 (MEK5D) in human primary endothelial cells (EC) to study the transcriptional and functional responses to Erk5 activation under static conditions.
Erk5 activation elicits a vasoprotective endothelial phenotype via induction of Kruppel-like factor 4 (KLF4).
Cell line
View SamplesThe protease activity of the paracaspase MALT1 plays an important role in antigen receptor-mediated lymphocyte activation by controlling the activity of the transcription factor NF-kB and is thus essential for the expression of inflammatory target genes.
MALT1 Protease Activity Controls the Expression of Inflammatory Genes in Keratinocytes upon Zymosan Stimulation.
Treatment
View SamplesInflammation has a causal role in many cancers. In prostate cancers, epidemiological data suggest a link between prostatitis and subsequent cancer development, but a proof for this concept in a tumor model has been lacking. A constitutively active version of the IkappaB kinase 2 (IKK2), the molecule activated by a plethora of inflammatory stimuli, was expressed specifically in the prostate epithelium. Signaling of the IKK2/NF-kappaB axis was insufficient for transformation of prostate tissue. However, while PTEN+/- epithelia exhibited intraepithelial neoplasias only recognizable by nuclear alterations, additional IKK2 activation led to an increase in tumor size and formation of cribriform structures and to a fiber increase in the fibroblastic stroma. This phenotype was coupled with inflammation in the prostate gland characterized by infiltration of granulocytes and macrophages. Molecular characterization of the tissues showed a specific loss of smooth muscle markers as well as expression of chemokines attracting immune cells. Isolation of epithelial and stromal cells showed differential chemokine expression by these cells. Correlation studies showed the inflammatory phenotype coupled to loss of smooth muscle in infiltrated glands, but maintenance of the phenotype in glands where inflammation had decreased. Despite the loss of the smooth muscle barrier, tumors were not invasive in a stable genetic background. Data mining revealed that smooth muscle markers are downregulated in human prostate cancers and literature data show that loss of these markers in primary tumors is associated with subsequent metastasis. Our data show that loss of smooth muscle and invasiveness of the tumor are not coupled. Thus, inflammation during early steps of tumorigenesis can lead to increased tumor size and a potential change in the subsequent metastatic potential, but the tumor requires an additional transformation to become a carcinoma.
Persistent inflammation leads to proliferative neoplasia and loss of smooth muscle cells in a prostate tumor model.
Age, Specimen part
View SamplesDuring development, thymocytes bearing a moderately self-reactive T cell receptor (TCR) can be selected to become regulatory T (Treg) cells. Several observations suggest that also in the periphery mature Treg cells continuously receive self-reactive TCR signals. However, the importance of this inherent autoreactivity for Treg cell biology remains poorly defined.
Continuous T cell receptor signals maintain a functional regulatory T cell pool.
Specimen part
View SamplesDiffuse large B-cell lymphoma (DLBCL) represents the most common form of lymphoma. We could show that in DLBCL cell lines the transcription factor NFAT is constitutively activated and drives the survival of a DLBCL subset. Aim of the analysis was to identify NFAT target genes in a NFAT-dependent (HBL-1) or -independent (HT) DLBCL cell line. To block NFAT activity, the DLBCL cells were treated with the calcineurin inhibitor cyclosporin A (CsA) up to 48 h. With this approach, we identified several survival-related NFAT target genes in HBL-1 cells that might explain the toxic effects of calcineurin inhibitors.
Targeting chronic NFAT activation with calcineurin inhibitors in diffuse large B-cell lymphoma.
Treatment
View SamplesMutations in ClC-5 cause Dent's disease, a disorder associated with low molecular weight proteinuria, hyperphosphaturia and kidney stones. ClC-5 is a Cl /H+-exchanger predominantly expressed in the kidney, where it facilitates the acidification of proximal tubular endosomes. The reduction in proximal tubular endocytosis resulting from a lack of ClC-5 raises the luminal concentration of filtered proteins and peptides like PTH.<br></br><br></br> We used gene expression profiling to identify possible signaling pathways that might be changed in ClC-5 KO kidneys, bones and intestines. Mouse model described in Piwon et al, ClC-5 Cl--channel disruption impairs endocytosis in a mouse model for Dent's disease, Nature 408, 369-373 (16 November 2000),doi: 10.1038/35042597
Kidney-specific upregulation of vitamin D3 target genes in ClC-5 KO mice.
Sex, Age, Specimen part, Subject
View SamplesPurpose: In acute myeloid leukemia (AML) without retinoic acid receptor (RAR) rearrangement the effect of all-trans retinoic acid (ATRA) is still poorly understood despite an association of NPM1 mutation and ATRA response. Recently, PRAME (preferentially expressed antigen in melanoma) has been shown to be a dominant repressor of RAR-signaling. Experimental design: Thus, we further investigated ATRA response mechanisms, especially the impact of PRAME expression on ATRA-responsiveness by profiling gene expression in K562 cell lines. Results: Our data revealed a PRAME-expression associated gene pattern to be significantly enriched for genes involved in the retinoic acid metabolic process. In leukemia cell line models we could demonstrate that retinoic acid-regulated cell proliferation and differentiation are impacted by PRAME expression. Conclusions: PRAME seems to impair differentiation and to increase proliferation likely via blocking RAR-signaling, which might be reversed by ATRA.
PRAME-induced inhibition of retinoic acid receptor signaling-mediated differentiation--a possible target for ATRA response in AML without t(15;17).
Treatment
View Samples3 pairs of wt and ClC-6 knockout mice, RNA from p14 hippocampus
Lysosomal storage disease upon disruption of the neuronal chloride transport protein ClC-6.
Sex, Age, Specimen part, Subject, Time
View SamplesThe objective of this study was to compare the transcriptional repertoire of mature human neutrophils before and after GM-CSF treatment by using oligonucleotide microarrays.
RhoH/TTF negatively regulates leukotriene production in neutrophils.
Specimen part
View SamplesBackground: Neuroblastoma is the most common extracranial solid tumor in childhood. The vast majority of stage M patients present with disseminated tumor cells (DTCs) in the bone marrow (BM). Although these cells represent a major obstacle in the treatment of neuroblastoma patients, their transcriptomic profile was not intensively analyzed so far. Results: RNA-Seq of stage M primary tumors, enriched BM-derived DTCs and the corresponding non-tumor mononuclear cells (MNCs) revealed that DTCs largely retained the gene expression signature of tumors. However, we identified 322 genes that were differentially expressed (q < 0.001, |log2FC|>2). Particularly genes encoded by mitochondrial DNA were highly up-regulated in DTCs, whereas e.g. genes involved in angiogenesis were down-regulated. Furthermore, 224 genes were highly expressed in DTCs and only slightly, if at all, in MNCs (q < 8x10-75 log2FC > 6). Interestingly, we found that the gene expression profiles of diagnostic DTCs largely resembled those of relapse DTCs with only 113 differentially expressed genes under relaxed cut-offs (q < 0.01, |log2FC| > 0.5). Notably, relapse DTCs showed a positional enrichment of 31 down-regulated genes encoded by chromosome 19, including five tumor suppressor genes (SIRT6, PUMA, STK11, CADM4 and GLTSCR2). Conclusion: This first RNA-Seq analysis of DTCs from neuroblastoma patients revealed their unique expression profile in comparison to the corresponding MNCs and tumor samples, and, interestingly, also expression differences between diagnostic and relapse DTCs preferentially affecting chromosome 19. As these alterations might be associated with treatment failure and disease relapse, they should be considered for further functional studies. Overall design: Tumor (n=16), bone marrow-derived disseminated tumor cells (n=42) and corresponding bone marrow-derived non-tumor cells (n=28) of stage M neuroblastoma patients were used for RNA-Seq
Neuroblastoma cells undergo transcriptomic alterations upon dissemination into the bone marrow and subsequent tumor progression.
Specimen part, Subject
View Samples