HOXB4 mediates expansion of adult and embryo-derived hematopoietic stem cells (HSCs) when expressed ectopically. To define the underlying molecular mechanisms, we performed gene expression profiling in combination with subsequent functional analysis using enriched adult HSCs expressing inducible HOXB4. A substantial number of the identified HOXB4 target genes are involved in signaling pathways important for controlling self-renewal, maintenance and differentiation of stem cells. Functional assays performed on selected pathways confirmed the biological coherence of the array results. HOXB4 activity protected adult HSCs from the detrimental effects mediated by the proinflammatory cytokine TNF-alpha. Furthermore, we demonstrate that HOXB4 activity and FGF-signaling are intertwined. HOXB4-mediated expansion of adult HSCs was enhanced by specific and complete inhibition of FGF-receptors. Based on our results we propose that HOXB4 governs pivotal cell-intrinsic pathways involved in the regulation of cell cycle, differentiation and apoptosis. Our results strongly suggest that HOXB4 modulates the response of HSCs to multiple extrinsic signals in a concerted manner, thereby shifting the balance towards stem cell self-renewal.
HOXB4's road map to stem cell expansion.
No sample metadata fields
View SamplesTo unravel the molecular mechanism by which HOXB4 promotes the expansion of early hematopoietic progenitors within differentiating ES cells, we analzed the gene expression profiles of embryoid bodies (EBs) in which transcription of HOXB4 had been induced or not induced. A substantial number of the identified HOXB4 target genes are involved in signaling pathways important for controlling self-renewal, maintenance and differentiation of stem cells. Furthermore, we demonstrate that HOXB4 activity and FGF-signaling are intertwined. HOXB4-mediated expansion of ES cell-derived early progenitors was enhanced by specific and complete inhibition of FGF-receptors. In contrast, the expanding activity of HOXB4 on hematopoietic progenitors in day4-6 embryoid bodies was blunted in the presence of basic FGF (FGF2) indicating a dominant negative effect of FGF-signaling on the earliest hematopoietic cells. Taken together, we show that modulation of FGF signaling is an essential feature of HOXB4 activity in the context of embryonic hematopoiesis.
HOXB4's road map to stem cell expansion.
No sample metadata fields
View SamplesGlioblastoma multiforme (GBM) is the most malignant and most common tumor of the central nervous system characterized by rapid growth and extensive tissue infiltration. GBM results in more years of life lost than any other cancer type. Notch signaling has been implicated in GBM pathogenesis through several modes of action. Inhibition of Notch leads to a reduction of cancer-initiating cells in gliomas and reduces proliferation and migration. Deltex1 (DTX1) is part of an alternative Notch signaling pathway distinct from the canonical MAML1/RBPJ-mediated cascade. In this study, we show that DTX1 activates both the RTK/PI3K/PKB as well as the MAPK/ERK pathway. Moreover, we found the anti-apoptotic factor Mcl-1 to be induced by DTX1. In accordance with this, the clonogenic potential and proliferation rates of glioma cell lines correlated with DTX1 levels. DTX1 knock down mitigated the tumorigenic potential in vivo, and overexpression of DTX1 increased cell migration and invasion of tumor cells accompanied by an elevation of the pro-migratory factors PKB and Snail1. Microarray gene expression analysis identified a DTX1-specific transcriptional program - including microRNA-21 - which is distinct from the canonical Notch signaling. We propose the alternative Notch pathway via DTX1 as oncogenic factor in malignant glioma and found low DTX1 expression levels to correlate with prolonged survival of GBM and early breast cancer patients in open source databases.
Deltex-1 activates mitotic signaling and proliferation and increases the clonogenic and invasive potential of U373 and LN18 glioblastoma cells and correlates with patient survival.
Specimen part, Cell line
View SamplesTo identify signaling pathways that are differentially regulated in human gliomas, a microarray analysis on 30 brain tumor samples (12 primary glioblastomas (GBM), 3 secondary glioblastomas (GBM-2), 8 astrocytomas (Astro) and 7 oligodendrogliomas (Oligo)) and on 5 glioblastoma cell lines (LN018, LN215, LN229, LN319 and BS149) was performed. Normal brain tissue (NB) and normal human astrocytes (NHA) were used as a control. Kinase expression in each tumor was compared to expression in normal brain and expression values from normal human astrocytes were used as an additional control.
MAP kinase-interacting kinase 1 regulates SMAD2-dependent TGF-β signaling pathway in human glioblastoma.
Sex, Age, Specimen part, Disease stage, Cell line
View SamplesAdamts12-deficient mice undergo more severe colitis than WT mice after induction with DSS.
ADAMTS-12 metalloprotease is necessary for normal inflammatory response.
Specimen part, Treatment
View SamplesOriginal patient tumor is directly implanted in mice xenografts. Tumor is propagated to multiple mice for conduct of 6 arm treatment trials and control. Therapies are selected based on T0 and F0 genomic profiles.
Using a rhabdomyosarcoma patient-derived xenograft to examine precision medicine approaches and model acquired resistance.
No sample metadata fields
View SamplesUterine double conditional inactivation of Smad2 and Smad3 in mice results in endometrial dysregulation, infertility, and uterine cancer. Smad2/3 cKO mice demonstrate abnormal expression of genes involved in inflammation, cell-cycle checkpoint, migration, steroid biosynthesis, and SMAD1/5-driven genes. We performed RNA-sequencing to identify the gene expression differences between the uterine epithelium of control and Smad2/3 cKO. To control for estrous cycle variations, the uterine epithelium was collected from mice at 0.5 dpc. Global gene expression profiles of Smad2/3 cKO versus control mice was analyzed. Our RNA sequencing analysis was performed at 6 weeks of life and already showed significant differences in migratory (Agr2,Slit2) and inflammatory (Ccl20, Crispld2) markers between Smad2/3 cKO and control mice. Overall design: Two group comparison: uterine epithelium of control and Smad2/3 cKO mice. We generated a conditional knockout of Smad2/3 in the uterus and demonstrated that Smad2/3 plays a critical role in the endometrium, with disruption resulting in pubertal-onset uterine hyperplasia and ultimately fatal uterine cancer.
Uterine double-conditional inactivation of <i>Smad2</i> and <i>Smad3</i> in mice causes endometrial dysregulation, infertility, and uterine cancer.
Specimen part, Subject
View SamplesStem cell-derived tissues have wide potential for modelling developmental and pathological processes as well as cell-based therapy. However, it has proven difficult to generate several key cell types in vitro, including skeletal muscle. In vertebrates, skeletal muscles derive during embryogenesis from the presomitic mesoderm (PSM). Using PSM development as a guide to establish conditions for the differentiation of monolayer cultures of embryonic stem (ES) cells into PSM-like cells without the introduction of transgenes or cell sorting.
A Gradient of Glycolytic Activity Coordinates FGF and Wnt Signaling during Elongation of the Body Axis in Amniote Embryos.
Specimen part, Disease, Cell line, Treatment, Time
View SamplesBy utilizing mast cells lacking Dnmt3a, we found that this enzyme is involved in restraining mast cell responses to stimuli, both in vitro and in vivo.
<i>Dnmt3a</i> restrains mast cell inflammatory responses.
Sex, Specimen part, Treatment
View SamplesIn order to establish a list of candidate direct COUP-TFI gene targets in the inner ear, we analyzed the differential gene expression profiles of the wild-type and the COUP-TFI/ P0 inner ears.
Genome-wide analysis of binding sites and direct target genes of the orphan nuclear receptor NR2F1/COUP-TFI.
Specimen part
View Samples