Activated B-cell-like (ABC) and germinal center B-cell-like (GCB) diffuse large B-cell lymphoma (DLBCL) represent the two major molecular DLBCL subtypes. They are characterized by differences in clinical course and by divergent addiction to oncogenic pathways. To determine activity of novel compounds in these two subtypes, we conducted an unbiased pharmacologic in vitro screen. The phosphatidylinositol-3-kinase (PI3K) alpha/delta (PI3Ka/d) inhibitor AZD8835 showed marked potency in ABC DLBCL models, whereas the protein kinase B (AKT) inhibitor AZD5363 induced apoptosis in PTEN-deficient DLBCLs. These in vitro results were confirmed in various cell line xenograft and patient-derived xenograft mouse models in vivo. Treatment with AZD8835 induced inhibition of nuclear factor kappa-B (NF-kB) signaling, prompting us to combine AZD8835 with the Brutons tyrosine kinase (BTK) inhibitor ibrutinib. This combination was highly synergistic and effective both in vitro and in vivo. In contrast, the AKT inhibitor AZD5363 was effective in PTEN-deficient DLBCLs through downregulation of the oncogenic transcription factor MYC. Collectively our data suggest that patients should be stratified according to their oncogenic dependencies when treated with PI3K and AKT inhibitors.
Sensitivity to PI3K and AKT inhibitors is mediated by divergent molecular mechanisms in subtypes of DLBCL.
Cell line, Treatment
View SamplesIdentification of genes regulated by the transcription factor HNF4a2
HNF4alpha reduces proliferation of kidney cells and affects genes deregulated in renal cell carcinoma.
No sample metadata fields
View SamplesMantle cell lymphoma (MCL) is a mature B-cell lymphoma characterized by poor clinical outcome. Recent studies revealed the importance of BCR signaling in maintaining MCL survival. However, it remains unclear which role MALT1, an essential component of the CARD11-BCL10-MALT1 (CBM) complex that transfers BCR signaling to the NF-kB pathway, plays in the biology of MCL. Here we show that a subset of MCLs is addicted to MALT1, as its inhibition by either RNA or pharmacologic interference induced cytotoxicity both in vitro and in vivo. Gene expression profiling following MALT1 inhibition demonstrated that MALT1 controls a MYC-driven gene expression network predominantly through increased MYC protein stability. Thus our analyses identify a previously unappreciated regulatory mechanism of MYC expression. Investigating primary mouse splenocytes, we could demonstrate that MALT1 induced MYC regulation is not restricted to MCL, but represents a common mechanism of MYC regulation. MYC itself is pivotal for MCL survival as its downregulation and pharmacologic inhibition induced cytotoxicity in all MCL models. Collectively, these results provide a strong mechanistic rationale to investigate the therapeutic efficacy in targeting the MALT1-MYC axis in MCL patients.
B-cell receptor-driven MALT1 activity regulates MYC signaling in mantle cell lymphoma.
Specimen part, Cell line
View SamplesWe used microarrays to develop gene signatures for XBP1 and IRE1 in myeloma cells to explore the role of this UPR/differentiation pathway in proteasome inhibitor resistance.
Xbp1s-negative tumor B cells and pre-plasmablasts mediate therapeutic proteasome inhibitor resistance in multiple myeloma.
Specimen part, Cell line
View SamplesCD34+ hematopoietic stem/progenitor cells were isolated from human cord blood and amplified in vitro for 10-14 days in serum-free medium with specific cytokines (Ju et al., Eur. J. Cell Biol. 82, 75-86, 2003; Hacker et al., Nat. Immunol. 4, 380-386, 2003). Cultured progenitor cells were induced to differentiate into DC in RPMI medium supplemented with 10% fetal calf serum, 2 mM L-glutamine, 0.1 microM Beta-mercaptoethanol, 100 U/ml penicillin and streptomycin (GIBCO-BRL) and 500 U/ml GM-CSF, 500 U/ml IL-4 for 6 days with or without 10 ng/ml TGF-beta1 as indicated (0.5x10E6 cells/ml). Every 2 days growth factors were added and cells were maintained at 0.5x10E6 cells/ml cell density. RNA was prepared and subjected to microarray analysis.
Transforming growth factor beta1 up-regulates interferon regulatory factor 8 during dendritic cell development.
No sample metadata fields
View SamplesConstitutive activation of the anti-apoptotic NF-B signaling pathway is a hallmark of the activated B-cell-like (ABC) subtype of diffuse large B-cell lymphomas (DLBCL) that is characterized by adverse survival. Recurrent oncogenic mutations are found in the scaffold protein CARMA1 (CARD11) that connects B-cell receptor (BCR) signaling to the canonical NF-B pathway. We asked how far additional downstream processes are activated and contribute to the oncogenic potential of DLBCL-derived CARMA1 mutants. To this end, we expressed oncogenic CARMA1 mutants in the NF-B negative DLBCL lymphoma cell line BJAB. By a proteomic approach we identified recruitment of -Catenin and its destruction complex consisting of APC, AXIN1, CK1 and GSK3 to oncogenic CARMA1. Recruitment of the -Catenin destruction complex was independent of CARMA1-BCL10-MALT1 (CBM) complex formation or constitutive NF-B activation and promoted the stabilization of -Catenin. Elevated -Catenin expression was detected in cell lines and biopsies from ABC DLBCL that rely on chronic BCR signaling. Increased -Catenin amounts alone were not sufficient to induce classical WNT target gene signatures, but could augment TCF/LEF dependent transcriptional activation in response to WNT signaling. In conjunction with NF-B, -Catenin enhanced expression of immune suppressive IL-10 and repressed anti-tumoral CCL3, indicating that -Catenin may induce a favorable tumor microenvironment. Thus, parallel activation of NF-B and -Catenin signaling by gain-of-function mutations in CARMA1 can augment WNT stimulation and is required for maintaining high expression of distinct NF-B target genes and can thereby trigger cell intrinsic and extrinsic processes that promote DLBCL lymphomagenesis.
Oncogenic CARMA1 couples NF-κB and β-catenin signaling in diffuse large B-cell lymphomas.
Specimen part, Cell line
View SamplesWe aimed to define epithelial-specific genes in the kidney. In the developing mouse kidney at E12.5 epithelial cells are restricted to the ureteric bud, while mesenchymal cells surrounding the ureteric bud are non-epithelial. The mouse renal epithelial cell line mIMCD-3 was used to represent kidney epithelia in vitro. Gene expression was analyzed using Affymetrix microarrays in ureteric bud stalks, ureteric bud tips, and mIMCD-3 cells and compared to metanephric mesenchyme.
The transcription factor grainyhead-like 2 regulates the molecular composition of the epithelial apical junctional complex.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MEK inhibitors activate Wnt signalling and induce stem cell plasticity in colorectal cancer.
Specimen part, Treatment
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 SamplesThis SuperSeries is composed of the SubSeries listed below.
Genomic impact of transient low-dose decitabine treatment on primary AML cells.
Sex, Age, Specimen part, Disease, Treatment
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