Similar Datasets
Project description:Oncogenic transcription factors such as the leukemic fusion protein RUNX1/ETO, which drives t(8;21) acute myeloid leukemia (AML), constitute cancer-specific but highly challenging therapeutic targets. We used epigenomic profiling data for an RNAi screen to interrogate the transcriptional network maintaining t(8;21) AML. This strategy identified Cyclin D2 (CCND2) as a crucial transmitter of RUNX1/ETO-driven leukemic propagation. RUNX1/ETO cooperates with AP-1 to drive CCND2 expression. Knockdown or pharmacological inhibition of CCND2 by an approved drug significantly impairs leukemic expansion of patient-derived AML cells and engraftment in immunodeficient murine hosts. Our data demonstrate that RUNX1/ETO maintains leukemia by promoting cell cycle progression and identifies G1 CCND-CDK complexes as promising therapeutic targets for treatment of RUNX1/ETO-driven AML.
| S-EPMC6179967 | biostudies-literature
Project description:Oncogenic transcription factors such as the leukaemic fusion protein RUNX1/ETO constitute cancer-specific but highly challenging therapeutic targets, whose functions depend on pharmacologically tractable downstream pathways. Here we interrogated the transcriptional network of RUNX1/ETO in an in vitro/in vivo RNAi screen and identified Cyclin D2 (CCND2) as a crucial transmitter of RUNX1/ETO-driven leukemic propagation. RUNX1/ETO drives CCND2 expression by binding to a regulatory element upstream of the CCND2 promoter. Both knockdown of CCND2 and treatment with the CDK4/6 inhibitor palbociclib inhibited leukemic expansion patient-derived AML cells and impaired engraftment of immunodeficient murine hosts. Our data demonstrate that RUNX1/ETO drives leukaemia by directly promoting cell cycle progression and establish inhibition of G1 CCND-CDK complexes as a promising therapeutic strategy for RUNX1/ETO-driven AML.
2019-04-12 | GSE117107 | GEO
Project description:Oncogenic transcription factors such as the leukaemic fusion protein RUNX1/ETO constitute cancer-specific but highly challenging therapeutic targets, whose functions depend on pharmacologically tractable downstream pathways. Here we interrogated the transcriptional network of RUNX1/ETO in an in vitro/in vivo RNAi screen and identified Cyclin D2 (CCND2) as a crucial transmitter of RUNX1/ETO-driven leukemic propagation. RUNX1/ETO drives CCND2 expression by binding to a regulatory element upstream of the CCND2 promoter. Both knockdown of CCND2 and treatment with the CDK4/6 inhibitor palbociclib inhibited leukemic expansion patient-derived AML cells and impaired engraftment of immunodeficient murine hosts. Our data demonstrate that RUNX1/ETO drives leukaemia by directly promoting cell cycle progression and establish inhibition of G1 CCND-CDK complexes as a promising therapeutic strategy for RUNX1/ETO-driven AML.
2019-04-12 | GSE117105 | GEO
Project description:The Oncogenic Transcription Factor RUNX1/ETO Corrupts Cell Cycle regulation to Drive Leukemic Transformation
| PRJNA481051 | ENA
Project description:The Oncogenic Transcription Factor RUNX1/ETO Corrupts Cell Cycle regulation to Drive Leukemic Transformation [HiC]
| PRJNA481054 | ENA
Project description:The Oncogenic Transcription Factor RUNX1/ETO Corrupts Cell Cycle regulation to Drive Leukemic Transformation [ChIP]
| PRJNA481055 | ENA
Project description:Acute myeloid leukemia (AML) is a major blood cancer with poor prognosis. New therapies are needed to target oncogene-driven leukemia stem cells, which account for relapse and resistance. Chromosome translocation t(8;21), which produces RUNX1-ETO (R-E) fusion oncoprotein, is found in ~13% AML. R-E dominance negatively inhibits global gene expression regulated by RUNX1, a master transcription factor for hematopoiesis, causing increased self-renewal and blocked cell differentiation of hematopoietic progenitor cells, and eventually leukemia initiation. Methods: Connectivity-Map followed by biological activity testing were used to identify candidate compounds that can inhibit R-E-mediated gene transcription. Molecular mechanistic studies were also performed. Results: Glucocorticoid drugs, such as betamethasone and dexamethasone, were found to exhibit potent and selective in vitro and in vivo activities against R-E leukemia, as well as strong synergy when combined with chemotherapeutics. Microarray analysis showed that treatment with glucocorticoids significantly inhibited R-E's activity and reactivated that of RUNX1. Such gene expression changes caused differentiation and apoptosis of R-E leukemia cells. Our studies also show a possible molecular mechanism for the targeted therapy. Upon treatment with a glucocorticoid drug, more glucocorticoid receptor (GR) was translocated into the nucleus and bound to DNA, including promoters of RUNX1 target genes. GR was found to associate with RUNX1, but not R-E. This interaction increased binding of RUNX1 to DNA and reduced that of R-E, shifting to a RUNX1 dominance. Conclusion: Glucocorticoid drugs represent a targeted therapy for AML with chromosome translocation t(8:21). Given their high activity, favorable human pharmacokinetics as well as synergy with chemotherapeutics, glucocorticoids could be clinically useful to treat R-E AML.
| S-EPMC5928880 | biostudies-other
Project description:Mutations in chromatin regulator ASXL1 are frequently identified in myeloid malignancies, in particular ∼40% of patients with chronic myelomonocytic leukemia (CMML). ASXL1 mutations are associated with poor prognosis in CMML and significantly co-occur with NRAS mutations. Here, we show that concurrent ASXL1 and NRAS mutations defined a population of CMML patients who had shorter leukemia-free survival than those with ASXL1 mutation only. Corroborating this human data, Asxl1-/- accelerated CMML progression and promoted CMML transformation to acute myeloid leukemia (AML) in NrasG12D/+ mice. NrasG12D/+;Asxl1-/- (NA) leukemia cells displayed hyperactivation of MEK/ERK signaling, increased global levels of H3K27ac, upregulation of Flt3. Moreover, we find that NA-AML cells overexpressed all the major inhibitory immune checkpoint ligands: programmed death-ligand 1 (PD-L1)/PD-L2, CD155, and CD80/CD86. Among them, overexpression of PD-L1 and CD86 correlated with upregulation of AP-1 transcription factors (TFs) in NA-AML cells. An AP-1 inhibitor or short hairpin RNAs against AP-1 TF Jun decreased PD-L1 and CD86 expression in NA-AML cells. Once NA-AML cells were transplanted into syngeneic recipients, NA-derived T cells were not detectable. Host-derived wild-type T cells overexpressed programmed cell death protein 1 (PD-1) and T-cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT) receptors, leading to a predominant exhausted T-cell phenotype. Combined inhibition of MEK and BET resulted in downregulation of Flt3 and AP-1 expression, partial restoration of the immune microenvironment, enhancement of CD8 T-cell cytotoxicity, and prolonged survival in NA-AML mice. Our study suggests that combined targeted therapy and immunotherapy may be beneficial for treating secondary AML with concurrent ASXL1 and NRAS mutations.
| S-EPMC8854684 | biostudies-literature
Project description:Mutations in ASXL1 are frequent in patients with myelodysplastic syndrome (MDS) and are associated with adverse survival, yet the molecular pathogenesis of ASXL1 mutations (ASXL1-MT) is not fully understood. Recently, it has been found that deletion of Asxl1 or expression of C-terminal-truncating ASXL1-MTs inhibit myeloid differentiation and induce MDS-like disease in mice. Here, we find that SET-binding protein 1 (SETBP1) mutations (SETBP1-MT) are enriched among ASXL1-mutated MDS patients and associated with increased incidence of leukemic transformation, as well as shorter survival, suggesting that SETBP1-MT play a critical role in leukemic transformation of MDS. We identify that SETBP1-MT inhibit ubiquitination and subsequent degradation of SETBP1, resulting in increased expression. Expression of SETBP1-MT, in turn, inhibited protein phosphatase 2A activity, leading to Akt activation and enhanced expression of posterior Hoxa genes in ASXL1-mutant cells. Biologically, SETBP1-MT augmented ASXL1-MT-induced differentiation block, inhibited apoptosis and enhanced myeloid colony output. SETBP1-MT collaborated with ASXL1-MT in inducing acute myeloid leukemia in vivo. The combination of ASXL1-MT and SETBP1-MT activated a stem cell signature and repressed the tumor growth factor-? signaling pathway, in contrast to the ASXL1-MT-induced MDS model. These data reveal that SETBP1-MT are critical drivers of ASXL1-mutated MDS and identify several deregulated pathways as potential therapeutic targets in high-risk MDS.
| S-EPMC4501574 | biostudies-other
Project description:Pathological activation of the PI3K/AKT pathway is among the most frequent defects in human cancer and is also the cause of rare overgrowth disorders. Yet, unlike the related oncogenic RAS/MAPK pathway, there is currently no systematic understanding of the quantitative flow of information within PI3K/AKT signalling and how it is perturbed by disease-causing mutations. Here, we develop scalable, single-cell approaches for systematic studies of signal processing within the PI3K pathway, enabling precise calculations of its information transfer for different growth factors. Using genetically engineered human cell models with allele dose-dependent expression of PIK3CAH1047R, we show that this oncogene is not a simple, constitutive pathway activator but a context-dependent modulator of extracellular signal transfer. PIK3CAH1047R reduces information transfer downstream of IGF1 while selectively enhancing EGF-induced signalling and transcriptional responses. This leads to a gross reduction in signalling specificity, akin to “blurred” signal perception. The associated increase in signalling heterogeneity increases phenotypic diversity in a cervical cancer cell model and in human induced pluripotent stem cells. Collectively, these findings and the accompanying methodological advances lay the foundations for a systematic mapping of the quantitative mechanisms of PI3K/AKT-dependent signal processing and phenotypic control in health and disease.
2023-12-27 | GSE251956 | GEO