Primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) share a frequent constitutive activation of Janus-activated kinase (JAK) / signal transducer and activator of transcription (STAT) signaling pathway. Due to complex non-linear relations within the pathway, key dynamic properties remained to be identified to predict possible strategies for intervention. To untangle these features, we used dynamic pathway modeling that employs model development and calibration based on extensive quantitative data generation. Quantitative data were collected on JAK/STAT pathway signaling components in two lymphoma-derived cell lines, MedB-1 and L1236, representative of PMBL and cHL, respectively. We showed that the amounts of STAT5 and STAT6 are higher whereas the amount of SHP1 is lower in the two lymphoma cell lines compared to B cells from healthy donors. Distinctively, L1236 cells harbor more JAK2 and less SHP1 molecules per cell than MedB-1 or control cells. In our experimental setting interleukin-13 (IL13) stimulation levels remained constant over time. In MedB-1 cells surface IL13 receptor alpha 2 had a strong IL13-sequestering/decoy function. In both lymphoma cell lines we observed IL13-induced activation of interleukin-4 receptor alpha, JAK2 and STAT5, but not of STAT6, which was highly phosphorylated even without stimulus. Furthermore, the known STAT-inducible negative regulators CISH and SOCS3 were up-regulated within 2 hours in MedB-1 but not in L1236 cells. Global transcription profiling revealed 11 early and 16 sustained common genes up-regulated by IL13 in both lymphoma cell lines. Based on this detailed information we established two individual mathematical models, MedB-1 and L1236 model, which were able to describe the respective experimental data. Sensitivity analysis of the model identified six possible therapeutic targets able to reduce gene expression levels in L1236 cells and three in MedB-1 cells. By inhibition of STAT5 phosphorylation we successfully validated one of the predicted targets demonstrating the potential of the approach in guiding target identification for highly deregulated signaling networks in cancer cells. We established mathematical models of the JAK/STAT pathway in two lymphoma cell types (PMBL and cHL), able to reproduce experimental data and to predict possible therapeutic targets.
Dynamic mathematical modeling of IL13-induced signaling in Hodgkin and primary mediastinal B-cell lymphoma allows prediction of therapeutic targets.
Cell line, Time
View SamplesAcute myeloid leukemia (AML) with CEBPA mutations is determined as provisional entity in the current WHO. A difference in clinical outcome between single- (sm) and double-mutated (dm) cases has been reported, whereupon dm cases were shown to be associated with longer overall survival (OS). The occurrence and prognostic impact of concomitant molecular mutations in addition to CEBPAdm has not been assessed until now. Here, we investigated a cohort of 95 AML CEBPAdm cases for concomitant mutations. TET2 was found to be the most frequent mutation (32/94, 34.0%), followed by GATA2 (20/95, 21.0%), WT1 (13/95, 13.7%), DNMT3A (9/94, 9.6%), ASXL1 (9/95, 9.5%), NRAS (8/95, 8.4%), KRAS (3/94, 3.2%), IDH1/2 (6/95, 6.3%), FLT3-ITD (6/95, 6.3%), FLT3-TKD (2/95, 2.1%), NPM1 (2/95, 2.1%), and RUNX1 (1/94). No mutation was detected in MLL-PTD and TP53. With respect to prognostic impact, we observed that those cases harboring additional mutations in TET2 showed significant worse survival than wild-type cases (P=0.035), whereas GATA2 mutated cases showed improved survival (P=0.032). Further, using gene expression microarray analysis we identified no clear different clustering within the CEBPAdm cases with the distinct concomitant mutated genes. In conclusion, we demonstrated that 76.8% of CEBPAdm cases harbored additional alterations in other molecular markers and that CEBPA is a suitable MRD marker to control therapy.
CEBPA double-mutated acute myeloid leukaemia harbours concomitant molecular mutations in 76·8% of cases with TET2 and GATA2 alterations impacting prognosis.
Disease, Disease stage
View SamplesThe clinical impact of aberrant CEBPA promoter methylation (PM) in AML is controversial discussed. The aim of this study was to clarify the significance of aberrant CEBPA PM with regard to clinical features in a cohort of 572 de novo AML with wildtype CEBPA and normal karyotype. The distal promoter was methylated in 54/572 cases (9.41%) whereas proximal PM was never detected. Methylation of the core promoter was detected in only 8 of 326 cases (2.45%) and thus seems to be a rare event in AML. There was no correlation between CEBPA distal PM, age, sex, white blood cell (WBC) count or Hb levels at diagnosis. We also were not able to detect a significant correlation between the presence of CEBPA distal PM and molecular mutations such as FLT3-ITD, NPM1, AML1, MLL-PTD and IDH1. Solely the frequency of IDH2R140 mutations was significantly reduced in CEBPA distal PM positive compared to CEBPA distal PM negative cases (p=0.01). Furthermore, analysis of CEBPA mRNA expression level revealed no difference between CEBPA distal PM positive and CEBPA distal PM negative cases, suggesting that CEBPA distal PM has no influence on CEBPA expression. CEBPA distal PM did not show impact on overall survival (OS), event free survival (EFS) or incidence of relapse. Also when other mutations were taken into regard no prognostic impact of CEBPA distal PM could be shown. In contrast, a distinct expression profile of CEBPA distal PM positive cases compared to CEBPA mutated and CEBPA distal PM negative cases was observed. In addition, a significantly higher frequency of CEBPA distal PM was detected in RUNX1-RUNX1T1 positive AML compared to the CEBPA witdtype cases. We conclude that the presence of aberrant CEBPA PM has no clinical relevance and is therefore a negligible prognostic marker in de novo AML with normal karyotype.
Frequency and prognostic impact of CEBPA proximal, distal and core promoter methylation in normal karyotype AML: a study on 623 cases.
Disease
View SamplesBy WHO 2008, CEBPA-mutated AML became a provisional subentity, but it remains to be clarified how CEBPAmut AML with multilineage dysplasia (MLD; 50% dysplastic cells in 2-3 lineages) but no other MDS-related feature should be classified. We investigated 108 CEBPAmut AML (15.7-87.6 years) for the impact of MLD and genetic features. MLD-positive patients differed from MLD-negative only by lower mean WBC counts (p=0.004), but not by other blood values, biologic characteristics, cytogenetic risk profiles, or additional molecular markers (NPM1mut, FLT3-ITD/TKD, RUNX1, MLL-PTD, IDH1/2). Biallelic CEBPAmut differed from wild-type-cases by differential expression of 213 genes, but did not differ significantly between MLD-positive/-negative patients. Survival outcomes were improved for females and those <60 years, intermediate versus adverse karyotypes (p=0.021), and for biallelic versus monoallelic/homozygous CEBPAmut (p=0.060) in case of FLT3-ITD-negativity. In contrast, 2-year OS (MLD+: 56.5%; MLD-: 65.5%) and 2-year EFS (MLD+: 13.8 months; MLD-: 16.3 months) did not differ significantly between MLD-positive/-negative patients. By univariable Cox regression analysis, gender, age, WBC count and MRC-cytogenetic risk category only were prognostically relevant for OS, while MLD was irrelevant. Therefore, CEBPAmut AML patients should be characterized only according to mut-status, cytogenetic risk groups, or additional mutations, whereas dysplasia is not relevant for this subtype.
Multilineage dysplasia does not influence prognosis in CEBPA-mutated AML, supporting the WHO proposal to classify these patients as a unique entity.
Specimen part, Disease, Disease stage
View SamplesExternal stimulations of cells by hormones, growth factors or cytokines activate signal transduction pathways that subsequently induce a rearrangement of cellular gene expression. The representation and analysis of changes in the gene response is complicated, and essentially consists of multiple layered temporal responses. In such situations, matrix factorization techniques may provide efficient tools for the detailed temporal analysis. Related methods applied in bioinformatics intentionally do not take prior knowledge into account. In signal processing, factorization techniques incorporating data properties like second-order spatial and temporal structures have shown a robust performance. However, large-scale biological data rarely imply a natural order that allows the definition of an autocorrelation function. We therefore develop the concept of graph-autocorrelation. We encode prior knowledge like transcriptional regulation, protein interactions or metabolic pathways as a weighted directed graph. By linking features along this underlying graph, we introduce a partial ordering of the samples to define an autocorrelation function. Using this framework as constraint to the matrix factorization task allows us to set up the fast and robust graph decorrelation (GraDe) algorithm. To analyze the alterations in the gene response in IL-6 stimulated primary mouse hepatocytes by GraDe, a time-course microarray experiment was performed. Extracted gene expression profiles show that IL-6 activates genes involved in cell cycle progression and cell division in a time-resolved manner. On the contrary, genes linked to metabolic and apoptotic processes are down-regulated indicating that IL-6 mediated priming rendered hepatocytes more responsive towards cell proliferation and reduces expenses for the energy household.
Knowledge-based matrix factorization temporally resolves the cellular responses to IL-6 stimulation.
Specimen part, Treatment, Time
View SamplesRNA-Seq analysis was performed to identify differentially expressed transcripts in primary AML bone marrow derived mononuclear cells compared to healthy (normal) peripheral blood mononuclear cells.
No associated publication
Sex, Age, Specimen part, Disease, Disease stage, Race
View SamplesWe have used lentiviral mediated knock down of SMARCB1, a subunit of the mammalian SWI/SNF complex in HL60, an acute promyelocytic leukemia cell line followed by high throughput mRNA sequencing to identify differentially expressed genes. We have used this data to identify genes affected by SMARCB1 depletion, and thus understand contribution of SMARCB1 towards leukemogenesis.
No associated publication
Sex, Age, Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Global analysis of the relationship between JIL-1 kinase and transcription.
Specimen part, Cell line
View SamplesPositioned nucleosomes limit the access of proteins to DNA and implement regulatory features encoded in eukaryotic genomes. Here we generated the first genome-wide nucleosome positioning map for Schizosaccharomyces pombe and annotated transcription start and termination sites genome-wide. Using this resource we found surprising differences compared to the nucleosome organization in the distantly related yeast Saccharomyces cerevisiae [the cerevisiae data has been published by others (PMID: 17873876) and the raw data is deposited at ArrayExpress(E-MEXP-1172)]. DNA sequence guides nucleosome positioning differently, e.g., poly(dA:dT) elements are not enriched in S. pombe nucleosome-depleted regions (NDRs). Regular nucleosomal arrays emanate more asymmetrically, i.e., mainly co-directionally with transcription, from promoter NDRs, but promoters harbouring the histone variant H2A.Z show regular arrays also upstream. Regular nucleosome phasing in S. pombe has a very short repeat length of 154 base pairs, and requires a remodeler, Mit1, conserved in humans but not found in S. cerevisiae. Nucleosome positioning mechanisms are evidently not universal but evolutionarily plastic.
Schizosaccharomyces pombe genome-wide nucleosome mapping reveals positioning mechanisms distinct from those of Saccharomyces cerevisiae.
No sample metadata fields
View SamplesISWI is an evolutionary conserved ATPase that catalyzes nucleosome remodeling in several different complexes. Two mammalian ISWI orthologs, SNF2H and SNF2L, have specialized functions despite their high similarity. Due to the lack of reagents the functions of SN2L in human cells had not been established. Newly established specific monoclonal antibodies and selective RNA interference protocols now enabled a comprehensive characterization of loss-of-function phenotypes in human cells. Contrasting earlier results obtained in the mouse model, we found SNF2L broadly expressed in primary human tissues. Depletion of SNF2L in HeLa cells led to enhanced proliferation, morphological alterations and increased migration. These phenomena were explained by transcriptome profiling, which identified SNF2L as a modulator of the Wnt signaling network. The cumulative effects of SNF2L depletion on gene expression portray the cell in a state of activated Wnt signaling characterized by increased proliferation and chemotactic locomotion. High levels of SNF2L expression in normal melanocytes contrast to undetectable expression in malignant melanoma. In summary, our data document an anti-correlation between SNF2L expression and several features characteristic of malignant cells.
Nucleosome remodeler SNF2L suppresses cell proliferation and migration and attenuates Wnt signaling.
Cell line
View Samples