Project description:Article title: Expression, regulation and function of phosphofructo-kinase/fructose-biphosphatases (PFKFBs) in glucocorticoid-induced apoptosis of acute lymphoblastic leukemia cells. Glucocorticoids (GCs) cause apoptosis and cell cycle arrest in lymphoid cells and constitute a central component in the therapy of lymphoid malignancies, most notably childhood acute lymphoblastic leukemia (ALL). PFKFB2 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-2), a kinase controlling glucose metabolism, was identified by us previously as a GC response gene in expression profiling analyses performed in children with ALL during initial systemic GC mono-therapy. Since deregulation of glucose metabolism has been implicated in apoptosis induction, this gene and its relatives PFKFB1, 3, and 4 were further analyzed. Expression analyses in additional ALL children, non-leukemic individuals and leukemic cell lines confirmed frequent PFKFB2 induction by GC in most systems sensitive to GC-induced apoptosis, particularly in T-ALL cells. The 3 other family members, in contrast, were not or weakly expressed (PFKFB1 and 4) or not induced by GC (PFKFB3). Conditional PFKFB2 over-expression in the CCRF-CEM T-ALL in vitro model revealed that its 2 splice variants (15A and 15B) did not have any detectable effect on survival or cell cycle progression. Moreover, neither PFKFB2 splice variant significantly affected sensitivity to, or kinetics of, GC-induced apoptosis. Our data suggest that, at least in the model system investigated, PFKFB2 is not an essential upstream regulator of the anti-leukemic effects of GC. Gene expression profiles of 4 non-leukemic individuals (1 healthy and 3 with epilepsy) were generated from mononuclear cells isolated from peripheral blood samples before, and after 2, 6, and 24 hours of in-vivo glucocorticoid treatment.
Project description:Gene expression data of glucocorticoid resistant and sensitive acute lymphoblastic leukemia cell lines for the article: Expression, regulation and function of phosphofructo-kinase/fructose-biphosphatases (PFKFBs) in glucocorticoid-induced apoptosis of acute lymphoblastic leukemia cells Glucocorticoids (GCs) cause apoptosis and cell cycle arrest in lymphoid cells and constitute a central component in the therapy of lymphoid malignancies, most notably childhood acute lymphoblastic leukemia (ALL). PFKFB2 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-2), a kinase controlling glucose metabolism, was identified by us previously as GC response gene in expression profiling analyses performed in children with ALL during initial systemic GC mono-therapy. Since deregulation of glucose metabolism has been implicated in apoptosis induction, this gene and its relatives PFKFB1, 3, and 4 were further analyzed. Expression analyses in additional ALL children, non-leukemic individuals and leukemic cell lines confirmed frequent PFKFB2 induction by GC in most systems sensitive to GC-induced apoptosis, particularly in T-ALL cells. The 3 other family members, in contrast, were not or weakly expressed (PFKFB1 and 4) or not induced by GC (PFKFB3). Conditional PFKFB2 over-expression in the CCRF-CEM T-ALL in vitro model revealed that its 2 splice variants (15A and 15B) did not have any detectable effect on survival or cell cycle progression. Moreover, neither PFKFB2 splice variant significantly affected sensitivity to, or kinetics of, GC-induced apoptosis. Our data suggest that, at least in the model system investigated, PFKFB2 is not an essential upstream regulator of the anti-leukemic effects of GC. Generation of the GC sensitive and resistant clones is described in Parson et al. FASEB J 2005 (Pubmed id 15637111). In brief GC sensitive clones were generated by limiting dilution subcloning from the GC sensitive T-ALL cell line CCRF-CEM-C7H2. To generate GC resistant clones the CCRF-CEM-C7H2 cell line was clutured in the presence of 10E-7 M dexametasone. Gene expression profiles of glucocorticoid (GC) resistant and sensitive T-ALL cells during GC treatment and corresponding control samples (cells treated with carrier control). GC induced regulation of PFKFB2 was determined in the various cell lines based on the expression intensities of the corresponding probe sets in GC treated and control samples.
Project description:Prednisolone is a potent anti-inflammatory glucocorticoid (GC) but chronic use is hampered by metabolic side effects. Although GCs are predominantly prescribed for treatment of inflammatory conditions, little is known about their long-term effects on gene-expression in-vivo during inflammation. Here, we aimed to identify genes underlying prednisolone-induced metabolic side effects in a complex in-vivo inflammatory setting after long-term treatment. We performed whole-genome expression profiling in liver and muscle from arthritic and non-arthritic mice treated with several doses of prednisolone for three weeks.
Project description:We investigated the anti-leukemic effects of the Bromodomain and Extra Terminal inhibitor I-BET151 on primary MLL-AF4 patient samples, using a xenotransplantation mouse model of MLL+ infant ALL in vivo. We reported that I-BET151 treatment impairs the engraftment and the disease burden of primary MLL+ infant ALL samples transplanted into immunedeficient mice. I-BET151 is able to arrest the growth of leukemic cells by blocking cell division and rapidly inducing apoptosis, through the deregulation of crucial target genes of the BRD4 and HOXA9/HOXA7 network. Moreover I-BET151 sensitizes glucocorticoid-resistant MLL+ cells to Prednisolone. Finally we observed that I-BET151 treatment is even more efficient when used in combination with HDAC inhibitor.
Project description:Glucocorticoids are an essential component of the treatment of lymphoid malignancies and resistance to glucocorticoid therapy constitutes a prominent clinical problem in relapsed and refractory lymphoblastic leukemias. Constitutively active NOTCH signaling is involved in the pathogenesis of over 50% of T-cell lymphoblastic leukemia (T-ALL) which harbor activating mutations in the NOTCH1 gene. Aberrant NOTCH1 signaling has been shown to protect normal thymocytes from glucocorticoid induced cell death. Here we analyzed the interaction of glucocorticoid therapy with inhibition of NOTCH signaling in the treatment of T-ALL. Gamma-secretase inhibitors (GSI), which block the activation of NOTCH receptors, amplified the transcriptional changes induced by glucocorticoid treatment, including glucocorticoid receptor autoinduction and restored sensitivity to dexamethasone in glucocorticoid-resistant T-ALL cells. Apoptosis induction upon inhibition of NOTCH signaling and activation of the glucocorticoid receptor was dependent on transcriptional upregulation of BIM and subsequent activation of the mitochondrial/intrinsic cell death pathway. Finally, we used a mouse xenograft model of T-ALL to demonstrate that combined treatment with dexamethasone and a GSI results in improved antileukemic effects in vivo. These studies provide insight in the mechanisms of glucocorticoid resistance and serve as rationale for the use of glucocorticoid and GSIs in combination in the treatment of T-ALL. Experiment Overall Design: Duplicate samples (biologic replicas) from CUTLL1 cells were treated for 24 hours with vehicle only (DMSO), dexamethasone (1microM), a gamma-secretase inhibitor (CompE 100nM) and a combination of dexamethasome plus gamma secretase inhibitor at the same concentrations indicated before. Gene expression profiling was analyzed to identify gene expression signatures assocuated with glucocorticoid treatment (dexamethasone), inhibition of NOTCH1 by gamma secretase inhibitor (CompE) or the combination of both treatments.
Project description:The use of glucocorticoids as growth promoters for meat-producing animals is strictly regulated within the European Union. However, in the past few years, a higher frequency of non-compliant bovine urine samples for prednisolone has been noticed, which could not be directly related to fraudulent use of prednisolone. As such, questions have risen about the origin of this compound. Unfortunately, at present, no decisive strategy has been established to discriminate between endogenous and exogenous prednisolone. In this study, an untargeted metabolomics strategy, based on Orbitrap and QqTOF mass spectrometry, was deployed to reveal urinary biomarkers, which are indicative for the exogenous administration of the synthetic glucocorticoid prednisolone. For this purpose, prednisolone was administered intramuscularly and per os to 12 bovines and a total of 2700 urine samples were collected before, during and after treatment. Multivariate statistical data analysis (i.e. OPLS-DA) revealed four differentiating metabolites that allowed discrimination between urine samples collected before and during prednisolone administration. None of these compounds were present in urine containing endogenous prednisolone, of which the formation was induced by the administration of a synthetic analogue of adrenocorticotropic hormone. Only one metabolite was retained as a highly suitable biomarker during growth-promoting and therapeutic prednisolone treatment, with 93.4 % sensitivity and 96.3 % specificity. Besides, this compound could be detected up to 4 days after a single therapeutic per os prednisolone administration. Based on accurate mass, isotope pattern, and MS/MS spectra, this compound was putatively annotated and is suggested as an actionable biomarker for exogenous prednisolone administration.
Project description:LC-MS data and DIA-NN search files relating to: PU.1 Eviction at Lymphocyte-Specific Chromatin Domains Mediates Glucocorticoid Response in Acute Lymphoblastic Leukemia.
Abstract: The epigenetic landscape plays a critical role in the onset and evolution of various malignancies, but its therapeutic utility remains underutilized. Glucocorticoids are an essential part of many multi-agent treatment regimens for lymphoid malignancies. However, the emergence of glucocorticoid resistance is a significant barrier to cure, which is in part due to epigenetic alterations, including aberrant chromatin accessibility and hypermethylation at lymphocyte-specific glucocorticoid-response elements (GREs). To gain a deeper understanding of regulatory mechanisms leading to these epigenetic alterations, we conducted a multi-omics study, including chromosome conformation capture sequencing (HiC), to examine changes in the 3D genome structure following the in vivo treatment of acute lymphoblastic leukemia (ALL) patient-derived xenografts (PDXs) with glucocorticoid. We found that glucocorticoid treatment led to distinct patterns of topologically associated domains (TADs) in glucocorticoid sensitive compared to resistant PDXs. Furthermore, we show that these TADs were primed by the development-related pioneer transcription factor PU.1, which extensively interacts with the glucocorticoid receptor (GR) exclusively in glucocorticoid-sensitive ALL PDXs. An integrative analysis of rapid immunoprecipitation mass spectrometry of endogenous protein (RIME) and ChIP-seq revealed that PU.1 binding was associated with lymphocyte-specific activation of GREs and GRE-interacting super-enhancers. The PU.1-associated TADs modulated epigenetic marks, and particularly the eviction of PU.1 promoted GR binding and the expression of signature genes, including BIM, ZBTB16 and RASA1, mediating glucocorticoid-induced apoptosis in ALL. These findings were phenocopied using a PU.1 inhibitor DB2313 to restore glucocorticoid sensitivity in ALL. Taken together, this study identified a new epigenetic pathway integrating PU.1 priming and PU.1-GR interaction which ultimately leads to PU.1 eviction in ALL. This pathway provides the first link between the activity of a lineage-specific transcription factor and epigenetic modulators mediating the response to glucocorticoids and thus offers a new avenue to translate fundamental epigenetic research into the clinic.
Project description:Article title: Expression, regulation and function of phosphofructo-kinase/fructose-biphosphatases (PFKFBs) in glucocorticoid-induced apoptosis of acute lymphoblastic leukemia cells. Glucocorticoids (GCs) cause apoptosis and cell cycle arrest in lymphoid cells and constitute a central component in the therapy of lymphoid malignancies, most notably childhood acute lymphoblastic leukemia (ALL). PFKFB2 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-2), a kinase controlling glucose metabolism, was identified by us previously as a GC response gene in expression profiling analyses performed in children with ALL during initial systemic GC mono-therapy. Since deregulation of glucose metabolism has been implicated in apoptosis induction, this gene and its relatives PFKFB1, 3, and 4 were further analyzed. Expression analyses in additional ALL children, non-leukemic individuals and leukemic cell lines confirmed frequent PFKFB2 induction by GC in most systems sensitive to GC-induced apoptosis, particularly in T-ALL cells. The 3 other family members, in contrast, were not or weakly expressed (PFKFB1 and 4) or not induced by GC (PFKFB3). Conditional PFKFB2 over-expression in the CCRF-CEM T-ALL in vitro model revealed that its 2 splice variants (15A and 15B) did not have any detectable effect on survival or cell cycle progression. Moreover, neither PFKFB2 splice variant significantly affected sensitivity to, or kinetics of, GC-induced apoptosis. Our data suggest that, at least in the model system investigated, PFKFB2 is not an essential upstream regulator of the anti-leukemic effects of GC.