Therapeutic efficacy of first-generation hypomethylating agents (HMAs) is limited in elderly acute myeloid leukemia (AML) patients. Therefore, combination strategies with targeted therapies are urgently needed. Here, we discover that priming with SGI-110 (guadecitabine), a next-generation HMA, sensitizes AML cells to ASTX660, a novel antagonist of cellular Inhibitor of Apoptosis Protein 1 and 2 (cIAP1/2) and X-linked IAP (XIAP). Importantly, SGI-110 and ASTX660 synergistically induced cell death in a panel of AML cell lines as well as in primary AML samples while largely sparing normal CD34+ human progenitor cells, underlining the translational relevance of this combination. Unbiased transcriptome analysis revealed that SGI-110 alone or in combination with ASTX660 upregulated the expression of key regulators of both extrinsic and intrinsic apoptosis signaling pathways such as TNFRSF10B (DR5), FAS and BAX. Individual knockdown of the death receptors TNFR1, DR5 and FAS significantly reduced SGI-110/ASTX660-mediated cell death, whereas blocking antibodies for TRAIL or FASLG failed to provide protection. Also, TNF-blocking antibody Enbrel had little protective effect on SGI110/ASTX660-induced cell death. Further, SGI-110 and ASTX660 acted in concert to promote cleavage of caspase-8 and BID, thereby providing a link between extrinsic and intrinsic apoptotic pathways. Consistently, sequential treatment with SGI-110 and ASTX660 triggered loss of mitochondrial membrane potential (MMP) and BAX activation, which contributes to cell death as BAX silencing significantly protected from SGI-110/ASTX660-mediated apoptosis. Together, these events culminated in activation of caspases-3/-7, nuclear fragmentation and cell death. In conclusion, SGI-110 and ASTX660 cooperatively induced apoptosis in AML cells by engaging extrinsic and intrinsic apoptosis pathways, highlighting the therapeutic potential of this combination for AML.
Next-generation hypomethylating agent SGI-110 primes acute myeloid leukemia cells to IAP antagonist by activating extrinsic and intrinsic apoptosis pathways.
Cell line
View SamplesGene expression analysis on purified murine hematopoietic stem cells (HSCs) deficient for Special AT-rich sequence-binding protein 1 (Satb1) compared to wild-type HSCs.
Satb1 regulates the self-renewal of hematopoietic stem cells by promoting quiescence and repressing differentiation commitment.
Specimen part
View SamplesRigosertib treatment of head and neck squamous cell cancer
The dual pathway inhibitor rigosertib is effective in direct patient tumor xenografts of head and neck squamous cell carcinomas.
Specimen part, Cell line
View SamplesExpression profiling of FACS purified Lin-cKit+ cells from compound URE-/+::Msh2-/- mice with AML and control animals
Minimal PU.1 reduction induces a preleukemic state and promotes development of acute myeloid leukemia.
No sample metadata fields
View SamplesExpression profiling of FACS purified Lin-cKit+ cells from preleukemic compound URE-/+::Msh2-/- mice and control animals (two separate pools of 3 mice each)
Minimal PU.1 reduction induces a preleukemic state and promotes development of acute myeloid leukemia.
No sample metadata fields
View SamplesGene expression analysis on purified human long-term hematopoietic stem cells (LT-HSC; CD34+CD38-CD90+) and short-term HSC (ST-HSC; CD34+CD38-CD90-) derived from healthy control patients and patients with myelodysplastic syndrome (MDS)
Stem and progenitor cells in myelodysplastic syndromes show aberrant stage-specific expansion and harbor genetic and epigenetic alterations.
Specimen part, Disease, Disease stage
View SamplesPrecise control of mRNA decay is fundamental for robust yet not exaggerated inflammatory responses to pathogens. Parameters determining the specificity and extent of mRNA degradation within the entire inflammation-associated transcriptome remain incompletely understood. Using transcriptome-wide high resolution occupancy assessment of the mRNA-destabilizing protein TTP, a major inflammation-limiting factor, we qualitatively and quantitatively characterize TTP binding positions and functionally relate them to TTP-dependent mRNA decay in immunostimulated macrophages. We identify pervasive TTP binding with incompletely penetrant linkage to mRNA destabilization. A necessary but not sufficient feature of TTP-mediated mRNA destabilization is binding to 3’ untranslated regions (UTRs). Mapping of binding positions of the mRNA-stabilizing protein HuR in activated macrophages revealed that TTP and HuR binding sites in 3’ UTRs occur mostly in different transcripts implicating only a limited co-regulation of inflammatory mRNAs by these proteins. Remarkably, we identify robust and widespread TTP binding to introns of stable transcripts. Nuclear TTP is associated with spliced-out introns and maintained in the nucleus throughout the inflammatory response. Our study establishes a functional annotation of binding positions dictating TTP-dependent mRNA decay in immunostimulated macrophages. The findings allow navigating the transcriptome-wide landscape of RNA elements controlling inflammation. Overall design: Experiment comparing RNA decay rates in WT and TTP-/- macrophages at LPS 3 h and 6 h. Transcription was blocked with actinomycin D for 0, 45 or 90 min. Decay rates was calculated using linear model.
Tristetraprolin binding site atlas in the macrophage transcriptome reveals a switch for inflammation resolution.
Specimen part, Cell line, Subject, Time
View SamplesPrecise control of mRNA decay is fundamental for robust yet not exaggerated inflammatory responses to pathogens. Parameters determining the specificity and extent of mRNA degradation within the entire inflammation-associated transcriptome remain incompletely understood. Using transcriptome-wide high resolution occupancy assessment of the mRNA-destabilizing protein TTP, a major inflammation-limiting factor, we qualitatively and quantitatively characterize TTP binding positions and functionally relate them to TTP-dependent mRNA decay in immunostimulated macrophages. We identify pervasive TTP binding with incompletely penetrant linkage to mRNA destabilization. A necessary but not sufficient feature of TTP-mediated mRNA destabilization is binding to 3’ untranslated regions (UTRs). Mapping of binding positions of the mRNA-stabilizing protein HuR in activated macrophages revealed that TTP and HuR binding sites in 3’ UTRs occur mostly in different transcripts implicating only a limited co-regulation of inflammatory mRNAs by these proteins. Remarkably, we identify robust and widespread TTP binding to introns of stable transcripts. Nuclear TTP is associated with spliced-out introns and maintained in the nucleus throughout the inflammatory response. Our study establishes a functional annotation of binding positions dictating TTP-dependent mRNA decay in immunostimulated macrophages. The findings allow navigating the transcriptome-wide landscape of RNA elements controlling inflammation. Overall design: RNA-Seq of RNA isolated from murine bone marrow derived macrophages (WT or TTP-deficient) stimulated for 6 h with LPS
Tristetraprolin binding site atlas in the macrophage transcriptome reveals a switch for inflammation resolution.
No sample metadata fields
View SamplesControlled decay of cytokine and chemokine mRNAs restrains the time and amplitude of inflammatory responses. Tristetraprolin (TTP) binds to AU-rich elements in 3 untranslated regions of mRNA and targets the bound mRNA for degradation. We have addressed here the function of TTP in balancing the macrophage activation state by a comprehensive analysis of TTP-dependent mRNA decay in LPS-stimulated macrophages from WT and TTP-deficient mice.
Tristetraprolin-driven regulatory circuit controls quality and timing of mRNA decay in inflammation.
Specimen part
View SamplesGRBATKO_BAT_COLDEXPOSURE
The glucocorticoid receptor in brown adipocytes is dispensable for control of energy homeostasis.
Specimen part
View Samples