This SuperSeries is composed of the SubSeries listed below.
Combined inhibition of receptor tyrosine and p21-activated kinases as a therapeutic strategy in childhood ALL.
Specimen part, Disease, Disease stage, Time
View SamplesThe purpose of this study was the principal investigation and frequency of RTK expression in primary T-ALLs. Primary initial T-ALLs were assessed regarding their transcriptome-wide expression profiles and screend for prominent RTK expression.
Combined inhibition of receptor tyrosine and p21-activated kinases as a therapeutic strategy in childhood ALL.
Disease, Disease stage
View SamplesDeregulated RTK activity has been implicated as a causal leukemogenic factor in the context of molecular aberrations that perturb differentiation in the hematopoietic lineage such as in childhood ALL. A deeper understanding of RTK signaling processes on a system-wide scale will be key in defining critical components of signaling networks. To link RTK activity with in vivo output in primary ALL we took a functional approach, which combined SH2 domain binding, mass spectrometry, and transcriptome analyses. Structure and composition of evolving networks were highly diverse with few generic features determined by receptor and cell type. A combinatorial assembly of varying context-dependent and few generic signaling components at multiple levels likely generates output specificity. PAK2 was identified as a phosphoregulated FLT3 target, whose allosteric inhibition resulted in apoptosis of ALL cells. Our studies provide evidence that a functional approach to leukemia signaling may yield valuable information for a network-directed intervention.
Combined inhibition of receptor tyrosine and p21-activated kinases as a therapeutic strategy in childhood ALL.
Specimen part, Time
View SamplesTumor relapse is associated with dismal prognosis, but responsible biological principles remain incompletely understood. To isolate and characterize relapse-inducing cells, we used genetic engineering and proliferation-sensitive dyes in patient-derived xenografts of acute lymphoblastic leukemia (ALL). We identified a rare subpopulation that resembled relapse-inducing cells with combined properties of long-term dormancy, treatment resistance, and stemness. Single-cell and bulk expression profiling revealed their similarity to primary ALL cells isolated from pediatric and adult patients at minimal residual disease (MRD). Therapeutically adverse characteristics were reversible, as resistant, dormant cells became sensitive to treatment and started proliferating when dissociated from the in vivo environment. Our data suggest that ALL patients might profit from therapeutic strategies that release MRD cells from the niche. Overall design: Gene expression profiles from two PDX ALL Samples (ALL-199 & ALL-265) were generated for either dormant (LRC) vs. dividing (non-LRC) cells or drug treated vs. non-treated cells. For single cell analysis one mouse were analyzed for each condition.
Characterization of Rare, Dormant, and Therapy-Resistant Cells in Acute Lymphoblastic Leukemia.
Specimen part, Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Loss of the histone methyltransferase EZH2 induces resistance to multiple drugs in acute myeloid leukemia.
Specimen part, Cell line
View SamplesHere, we analyzed global gene expression changes that were associated with drug resistance in Acute Myeloid Leukemia using the Affymetrix microarray platform.
Loss of the histone methyltransferase EZH2 induces resistance to multiple drugs in acute myeloid leukemia.
Specimen part, Cell line
View SamplesIntact living conduit vessels (umbilical veins) were exposed to normal or high intraluminal pressure, or low or high shear stress in combination with a physiological level of the other force. We used a unique vascular ex vivo perfusion system. After six hours of perfusion endothelial cells were isolated from the stimulated vessels and RNA was extracted. RNA from 16 experiments from each stimulation were pooled and analyzed in duplicate DNA microarrays.
Differential global gene expression response patterns of human endothelium exposed to shear stress and intraluminal pressure.
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View SamplesGlomerular podocytes are highly differentiated cells that are key components of the kidney filtration units. The podocyte cytoskeleton builds the basis for the dynamic podocyte cytoarchitecture and plays a central role for proper podocyte function. Recent studies implicate that immunosuppressive agents including the mTOR-inhibitor everolimus have a protective role directly on the stability of the podocyte cytoskeleton. To elucidate mechanisms underlying mTOR-inhibitor mediated cytoskeletal rearrangements, we carried out microarray gene expression studies to identify target genes and corresponding pathways in response to everolimus. We analyzed the effect of everolimus in a puromycin aminonucleoside experimental in vitro model of podocyte injury. Upon treatment with puromycin aminonucleoside, microarray analysis revealed gene clusters involving cytoskeletal-associated pathways, adhesion, migration and extracellular matrix composition to be affected. Everolimus is capable of protecting podocytes from injury, both on the transcriptome and protein level. Rescued genes included TUBB2B and DCDC2, both involved in microtubule structure formation in neuronal cells but not identified in podocytes so far. Confirming gene expression data, Western-blot analysis in cultured podocytes showed an increase of TUBB2B and DCDC2 protein after everolimus treatment, and immunohistochemistry in healthy control kidneys confirmed a podocyte-specific expression. Microtubule-inhibitor experiments led to a maldistribution of TUBB2B and DCDC2 as well as an aberrant reorganization of the actin cytoskeleton. Tubb2bbrdp/brdp mice showed a delay in glomerular podocyte and capillary development. Taken together, our study suggests that off-target, non-immune mediated effects of the mTOR-inhibitor everolimus on the podocyte cytoskeleton might involve regulation of microtubules, revealing a potential novel role of TUBB2B and DCDC2 in glomerular podocyte development
Everolimus Stabilizes Podocyte Microtubules via Enhancing TUBB2B and DCDC2 Expression.
Specimen part, Treatment
View SamplesOxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major medical problem, and predictive markers are urgently needed. Recently, miR-625-3p was reported as a promising predictive marker. Here, we have used in vitro models to show that miR-625-3p functionally induces oxPt resistance in CRC cells, and have identified signalling networks affected by miR-625-3p. The p38 MAPK activator MAP2K6 was shown to be a direct target of miR-625-3p, and, accordingly, was downregulated in patients not responding to oxPt therapy. miR-625-3p resistance could be reversed in CRC cells by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. In addition, by reducing p38 MAPK signalling using either siRNA technology, chemical inhibitors to p38 or by ectopic expression of dominant negative MAP2K6 protein we induced resistance to oxPt. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signalling as one likely mechanism a possible driving force behind of oxPt resistance. Our study shows that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks, and corroborates the predictive power of miR-625-3p
miR-625-3p regulates oxaliplatin resistance by targeting MAP2K6-p38 signalling in human colorectal adenocarcinoma cells.
Subject
View SamplesChromosome 5q deletions (del(5q)) are common in high-risk (HR) Myelodysplastic Syndrome (MDS) and Acute Myeloid Leukemia (AML); however, the gene regulatory networks that sustain these aggressive diseases are unknown. Reduced miR-146a expression in del(5q) HR-MDS/AML and miR-146a-/- hematopoietic stem/progenitor cells (HSPC) results in TRAF6/NF- activation. Increased survival and proliferation of HSPC from miR-146alow HR-MDS/AML is sustained by a neighboring haploid gene, SQSTM1 (p62), expressed from the intact 5q allele. Overexpression of p62 from the intact allele occurs through NF-B-dependent feedforward signaling mediated by miR-146a deficiency. p62 is necessary for TRAF6-mediated NF-B signaling, as disrupting the p62-TRAF6 signaling complex results in cell cycle arrest and apoptosis of MDS/AML cells. Thus, del(5q) HR-MDS/AML employs an intrachromosomal gene network involving loss of miR-146a and haploid overexpression of p62 via NF-B to sustain TRAF6/NF-B signaling for cell survival and proliferation. Interfering with the p62-TRAF6 signaling complex represents a therapeutic option in miR-146a-deficient and aggressive del(5q) MDS/AML.
Myeloid malignancies with chromosome 5q deletions acquire a dependency on an intrachromosomal NF-κB gene network.
Sex, Specimen part
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