This SuperSeries is composed of the SubSeries listed below.
The B-cell receptor controls fitness of MYC-driven lymphoma cells via GSK3β inhibition.
No sample metadata fields
View SamplesSimilar to resting mature B cells, where the B-cell antigen receptor (BCR) is essential for cellular survival, surface BCR expression is conserved in most mature B cell lymphomas. The identification of activating BCR mutations and the growth disadvantage upon BCR knockdown of cells of certain lymphoma entities has led to the view that BCR signaling is required for tumour cell survival. Consequently, the BCR signaling machinery has become a new target in the therapy of B cell malignancies. Here, we studied the effects of BCR ablation on MYC-driven mouse B cell lymphomas and compared them to observations in human Burkitt lymphoma. Whereas BCR ablation did not, per se, significantly affect lymphoma growth, BCR-negative (BCR-) tumour cells rapidly disappeared in the presence of their BCR-expressing (BCR+) counterparts in vitro and in vivo. This required neither cellular contact, nor factors released by BCR+ tumour cells. Instead, BCR loss induced the rewiring of central carbon metabolism increasing the sensitivity of receptor-less lymphoma cells to nutrient restriction. The BCR attenuated GSK3 activity to support MYC-controlled gene expression. BCR- tumour cells exhibited increased GSK3 activity and were rescued from their competitive growth disadvantage by GSK3. BCR-negative lymphoma variants that restored competitive fitness, normalized GSK3 following constitutive activation of the MAPK pathway, commonly through Ras mutations. Similarly, in Burkitt lymphoma, activating RAS mutations may propagate Ig-crippled tumour cells, which usually represent a minority of the tumour bulk. Thus, while BCR expression enhances lymphoma cell fitness, BCR-targeted therapies may profit from combinations with drugs targeting BCR-less tumour cells.
The B-cell receptor controls fitness of MYC-driven lymphoma cells via GSK3β inhibition.
No sample metadata fields
View SamplesProfiling CD34+ BCR-ABL+ cells of CML patients in chronic phase or blast crisis to identify differentially expressed stage-specific genes.
Gene expression profiling of CD34+ cells identifies a molecular signature of chronic myeloid leukemia blast crisis.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesTranscript dynamics in mitotic exit mutants in the S. cerevisiae BF264-15D strain background. We examined the extent to which periodic cell-cycle transcription persisted in cells arrested in anaphase with intermediate level of B-cyclins.
Reconciling conflicting models for global control of cell-cycle transcription.
No sample metadata fields
View SamplesDuring HIV-1 infection, there is a massive perturbation of host gene expression, but as yet, genome-wide studies have not identified host genes affecting HIV-1 replication in lymphatic tissue, the primary site of virus-host interactions. In this study, we isolated RNA from the inguinal lymph nodes of 22 HIV-1-infected individuals and utilized a microarray approach to identify host genes critically important for viral replication in lymphatic tissue by examining gene expression associated with viral load. Strikingly, ~95% of the transcripts (558) in this data set (592 transcripts total) were negatively associated with HIV-1 replication. Genes in this subset (1) inhibit cellular activation/proliferation (ex.: TCFL5, SOCS5 and SCOS7, KLF10), (2) promote heterochromatin formation (ex.: HIC2, CREBZF, ZNF148/ZBP-89), (3) increase collagen synthesis (ex.: PLOD2, POSTN, CRTAP), and (4) reduce cellular transcription and translation. Potential anti-HIV-1 restriction factors were also identified (ex.: NR3C1, HNRNPU, PACT). Only ~5% of the transcripts (34) were positively associated with HIV-1 replication. Paradoxically, nearly all these genes function in innate and adaptive immunity, particularly highlighting a heightened interferon system. The predominance of negative correlations as well as the disconnect between host defenses and viral load point to the importance of genes that regulate target cell activation and genes that code for potentially new restriction factors as determinants of viral load rather than conventional host defenses.
Host genes associated with HIV-1 replication in lymphatic tissue.
Sex, Age, Specimen part, Race
View SamplesBackground: ETV6/RUNX1 (E/R) (also known as TEL/AML1) is the most frequent gene fusion in childhood acute lymphoblastic leukemia (ALL) and also most likely the crucial factor for disease initiation, whereas its role in leukemia propagation and maintenance remains largely elusive. To address this issue we performed a shRNA-mediated knock-down (KD) of the E/R fusion gene and investigated the ensuing consequences on genome-wide gene expression patterns and deducible regulatory functions in two E/R-positive leukemic cell lines. Findings: Microarray analyses identified 777 genes whose expression was substantially altered. Although approximately equal proportions were either up- (KD-UP) or down-regulated (KD-DOWN), the effects on biological processes and pathways differed considerably. The E/R KD-DOWN set was significantly enriched for genes included in the cell activation, immune response, apoptosis, signal transduction and development and differentiation categories, whereas in the E/R KD-UP set only the PI3K/AKT/mTOR signaling and hematopoietic stem cells categories became evident. Comparable expression signatures obtained from primary E/R-positive ALL samples underline the relevance of these pathways and molecular functions. We also validated six differentially expressed genes representing the categories stem cell properties, B-cell differentiation, immune response, cell adhesion and DNA damage with RT-qPCR. Conclusion: The results of our analyses provide the first preliminary evidence that the continuous expression of the E/R fusion gene interferes with regular B-cell development by repressing key functions that are necessary under physiological circumstances. E/R may thus constitute also the essential driving force for the propagation and maintenance of the leukemic process irrespective of potential consequences of associated secondary changes. Finally, these findings may also provide a valuable source of potentially attractive therapeutic targets.
The leukemia-specific fusion gene ETV6/RUNX1 perturbs distinct key biological functions primarily by gene repression.
Cell line, Treatment
View SamplesDU145 prostate cancer cells were treated with 50 ng/ml FGF19 and 50 ug/ml heparin, or 10 ng/ml TNFalpha, or both
The receptor tyrosine kinase FGFR4 negatively regulates NF-kappaB signaling.
Cell line
View SamplesUntreated HIV-1 infection progresses through acute and asymptomatic stages to AIDS. While each of the three stages has well-known clinical, virologic and immunological characteristics, much less is known of the molecular mechanisms underlying each stage. Here we report lymphatic tissue microarray analyses revealing for the first time stage-specific patterns of gene expression during HIV-1 infection. We show that while there is a common set of key genes with altered expression throughout all stages, each stage has a unique gene-expression signature. The acute stage is most notably characterized by increased expression of hundreds of genes involved in immune activation, innate immune defenses (e.g.MDA-5, TLR-7 and -8, PKR, APOBEC3B, 3F, 3G), adaptive immunity, and in the pro-apoptotic Fas-Fas-L pathway. Yet, quite strikingly, the expression of nearly all acute-stage genes return to baseline levels in the asymptomatic stage, accompanying partial control of infection. In the AIDS stage, decreased expression of numerous genes involved in T cell signaling identifies genes contributing to T cell dysfunction. These common and stage-specific, gene-expression signatures provide new insights into the molecular mechanisms underlying the host response and the slow, natural course of HIV-1 infection.
Microarray analysis of lymphatic tissue reveals stage-specific, gene expression signatures in HIV-1 infection.
Sex, Age, Specimen part, Disease, Disease stage, Race, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Novel targets of the CbrAB/Crc carbon catabolite control system revealed by transcript abundance in Pseudomonas aeruginosa.
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View SamplesThe ubiquitous efflux transporter ATP-binding cassette sub-family C member 5 (ABCC5) is present at high levels in the blood-brain barrier, neurons and glia, but its in vivo substrates and function are not known. Untargeted metabolomic screens revealed that Abcc5-/- mice accumulate endogenous glutamate conjugates and analogs in several tissues, but brain in particular. The abundant neurotransmitter N-acetylaspartylglutamate (NAAG), for example, was over 2-fold higher in Abcc5-/- brain. In line with ABCC5-mediated transport, the metabolites that accumulated in Abcc5-/- tissues were depleted in cultured cells that overexpressed human ABCC5. Using membrane vesicles, we show that ABCC5 not only transports the metabolites detected in our screen, but also a wide range of peptides containing a C-terminal glutamate. Glutamate conjugates are of physiological relevance because they can affect the function of glutamate, the principal excitatory neurotransmitter in the brain. We found that ABCC5 also transports exogenous glutamate analogs, like the classic excitotoxic neurotoxins kainic acid, domoic acid and N-methyl-D-aspartate (NMDA) and the therapeutic glutamate analog ZJ43. Taken together, we have identified ABCC5 as a general glutamate conjugate and analog transporter that affects the disposition of endogenous metabolites, toxins and drugs. Overall design: A set of 5 wildtype brains was compared to a set of 5 Abcc5-knockout mouse brains
ATP-binding Cassette Subfamily C Member 5 (ABCC5) Functions as an Efflux Transporter of Glutamate Conjugates and Analogs.
No sample metadata fields
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