The NF-B pathway is a critical regulator of the immune system and has been implicated in cellular transformation and tumorigenesis. NF-B response is regulated by the activation state of the IB kinase (IKK) complex and triggered by a wide spectrum of stimuli. We previously reported that NF-B is downstream of Notch1 in T cell acute lymphoblastic leukaemia (T-ALL), however both the mechanisms involving Notch1-induced NF-B activation and the potential importance of NF-B in the maintenance of the disease are unknown. Here we visualize Notch-induced NF-B activation using both human T-ALL cell lines and animal models of this type of leukemia. We show that it is not Notch1 itself but Hes1, a canonical Notch target, the responsible for sustaining IKK activation in T-ALL. Hes1 exerts its effects by a direct transcriptional repression of the deubiquitinating enzyme CYLD, a well-characterized IKK inhibitor. Consistently, CYLD expression is significantly reduced in primary T-ALL leukemias. Finally, we demonstrate that IKK complex inhibition is a promising option for the targeted therapy of T-ALL as suppression of IKK function affected both the survival of human T-ALL cells in vitro and the maintenance of the disease in vivo.
The Notch/Hes1 pathway sustains NF-κB activation through CYLD repression in T cell leukemia.
Specimen part, Cell line
View SamplesUbiquitination is a post-translational mechanism of control of diverse cellular processes. We focus here on the ubiquitin ligase Fbw7, a recently identified hematopoietic tumor suppressor that can target for degradation several important oncogenes including Notch1, c-Myc and cyclin E. We have generated conditional Fbw7 knock-out animals and inactivated the gene in hematopoietic stem cells (HSC) and their differentiated progeny. Deletion of Fbw7 specifically and rapidly affects the HSC compartment in a cell-autonomous manner. Fbw7-/- HSCs show defective maintenance of quiescence, leading to impaired self-renewal and a severe loss of competitive repopulating capacity. Furthermore, Fbw7-/- HSC are unable to colonize the thymus leading to a profound depletion of T cell progenitors. Deletion of Fbw7 in bone marrow stem cells and progenitors leads to the stabilization of c-Myc, a transcription factor previously implicated in HSC self-renewal. On the other hand, neither Notch1 nor cyclin E are stabilized in the bone marrow of Fbw7 deficient mice. Genome-wide transcriptome studies of Fbw7-/- HSC and hematopoietic progenitors indicate that Fbw7 controls, through the regulation of HSC cell cycle entry, the global transcriptional signature that is associated with the quiescent, self-renewing HSC phenotype.
Control of hematopoietic stem cell quiescence by the E3 ubiquitin ligase Fbw7.
No sample metadata fields
View SamplesThe Hedgehog (Hh) signaling pathway is a developmentally conserved regulator of stem cell function. Several reports suggested that Hh signaling is an important regulator of hematopoietic stem cell (HSC) maintenance and differentiation. Here we test this hypothesis in vivo using both gain- and loss-of-function Hh genetic models. Surprisingly, our studies demonstrate that conditional Smoothened (Smo) deletion or over-activation has no significant effects on adult HSC self-renewal and function. Moreover, they indicate a lack of synergism between the Notch and Hh pathways in HSC function, as RBPJ- and Smo-deficiency do not affect hematopoiesis. In agreement with this notion, detailed genome-wide transcriptome analysis reveals that silencing of Hh signaling does not significantly alter the HSC-specific gene expression signature. Our studies demonstrate that the Hh signaling pathway is dispensable for adult HSC function and suggest that the Hh pathway can be targeted in future clinical trials addressing the effect of Hh inhibition on leukemia-initiating cell maintenance.
Hedgehog signaling is dispensable for adult hematopoietic stem cell function.
Sex
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MED12 Regulates HSC-Specific Enhancers Independently of Mediator Kinase Activity to Control Hematopoiesis.
Specimen part, Cell line
View SamplesmTOR coordinates growth signals with metabolic pathways and protein synthesis and is hyperactivated in many human cancers. We have characterized the coordinated mTORC1 and -2 transcription and translation response using genome-wide translatome and transcriptome profiling on cells inhibited in mTORC1/2 with PP242 or only mTORC1 with RAD001, with or without concurrent IR.
No associated publication
Cell line
View SamplesUsing platinum-resistant OVCAR-3 cells treated with the selective mTORC1/2 inhibitor INK128/MLN128, we conducted genome-wide transcription and translation studies and analyzed the effect on cell proliferation, AKT-mTOR signaling and cell survival, to determine whether carboplatin resistance involves selective mRNA translational reprogramming, and whether it is sensitive to mTORC1/2 inhibitio.n
No associated publication
Specimen part, Cell line
View SamplesOrgan transplant recipients (OTRs) on Cyclosporine A (CSA) are prone to catastrophic cutaneous squamous cell carcinoma (SCC). Allograft-sparing, cancer-targeting systemic treatments are unavailable. We have shown increased risk for catastrophic SCC in OTRs via CSA-mediated induction of Interleukin-22 (IL-22). Herein, we found CSA drives SCC proliferation and tumor growth through IL-22 and JAK/STAT pathway induction. We in turn inhibited SCC growth with an FDA-approved JAK 1/2 inhibitor, Ruxolitinib. In human SCC cells, greatest proliferative response to IL-22 and CSA treatment occurred in non-metastasizing lines. IL-22 treatment upregulated JAK1 and STAT1/3 in A431 SCC cells. JAK/STAT pathway genes were highly expressed in tumors from a cohort of CSA-exposed OTRs, and in SCC with high risk for metastasis. Compared to immunocompetent SCC, genes associated with innate immunity, response to DNA damage and p53 regulation were differentially expressed in SCC from OTRs. In nude mice engrafted with human A431 cells, IL-22 and CSA treatment increased tumor growth and upregulated IL-22 receptor, JAK1 and STAT 1/3 expression. Ruxolitinib treatment significantly reduced tumor volume and reversed the accelerated tumor growth. CSA and IL-22 exacerbate aggressive behavior in SCC. Targeting the IL-22 axis via selective JAK/STAT inhibition may reduce the progression of aggressive SCC in OTRs, without compromising immunosuppression.
Ruxolitinib inhibits cyclosporine-induced proliferation of cutaneous squamous cell carcinoma.
No sample metadata fields
View SamplesThe early life microbiome plays important roles in host immunological and metabolic development. Because type 1 diabetes (T1D) incidence has been increasing substantially in recent decades, we hypothesized that early-life antibiotic use alters gut microbiota that predisposes to disease. Using NOD mice that are genetically susceptible to T1D, we examined the effects of exposure to either continuous low-dose antibiotics or pulsed therapeutic antibiotics (PAT) early in life, mimicking childhood exposures. We found that in mice receiving PAT, T1D incidence was significantly higher, microbial community composition and structure differed compared with controls. In pre-diabetic male PAT mice, the intestinal lamina propria had lower Th17 and T reg proportions and intestinal SAA expression than in controls, suggesting key roles in transducing the altered microbiota signals. PAT affected microbial lipid metabolism and host cholesterol biosynthetic gene expression. These findings show that early-life antibiotic treatments alter the gut microbiota and its metabolic capacities, intestinal gene expression, and T-cell populations, accelerating T1D onset in NOD mice.
Antibiotic-mediated gut microbiome perturbation accelerates development of type 1 diabetes in mice.
Sex, Specimen part, Disease, Disease stage, Treatment
View SamplesGlucocorticoids (GCs) have a long history of use as therapeutic agents for numerous skin diseases. Surprisingly, their specific molecular effects are largely unknown. To characterize GC action in epidermis, we compared the transcriptional profiles of primary human keratinocytes untreated and treated with dexamethasone (DEX) for 1, 4, 24, 48 and 72 hours using large-scale microarray analyses. The majority of genes were found regulated only after 24 hours and remained regulated throughout the treatment. In addition to expected anti-inflammatory genes, we found that GCs regulate cell fate, tissue remodeling, cell motility, differentiation and metabolism. GCs not only effectively block signaling by TNF-alpha and IL-1 but also by IFN-gamma, which was not previously known. Specifically, GCs suppress the expression of essentially all IFN-gamma-regulated genes, including IFN-gamma receptor and STAT-1. GCs also block STAT-1 activation and nuclear translocation. Unexpectedly, GCs have anti-apoptotic effects in keratinocytes by inducing the expression of anti-apoptotic and repressing pro-apoptotic genes. Consequently, GCs treatment blocked UV-induced apoptosis of keratinocytes. GCs have a profound effect on wound healing by inhibiting cell motility and the expression of pro-angiogenic factor VEGF. They play an important role in tissue remodeling and scar formation by suppressing the expression of TGF-beta-1 and -2, MMP1, 2, 9 and 10 and inducing TIMP-2. Finally, GCs promote terminal stages of epidermal differentiation while simultaneously inhibiting the early stages. These results provide new insights into the beneficial and adverse effects of GCs in epidermis, defining the participating genes and mechanisms that coordinate the cellular responses important for GC-based therapies.
Novel genomic effects of glucocorticoids in epidermal keratinocytes: inhibition of apoptosis, interferon-gamma pathway, and wound healing along with promotion of terminal differentiation.
Specimen part, Treatment
View SamplesCultured epidermal keratinocytes treated with OsM 1, 4, 24 & 48hrs, and Skinethic epidermal substitutes treated 1, 4, 24, 48h & 7days, each with untreated control
Transcriptional responses of human epidermal keratinocytes to Oncostatin-M.
No sample metadata fields
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