RIPK3 restricts myeloid leukemogenesis by promoting cell death and differentiation of leukemia initiating cells
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ABSTRACT: Examination of gene expression patterns in lineage negative FLT3-ITD– and pMIG-transduced BM cells via microarray study. We performed a global mRNA profiling analysis of murine Lin– FLT3-ITD+ cells compared to empty-vector controls, purified 48h after transduction. We examined association patterns of FLT3-ITD and pMIG cells and identified a specific gene expression signature associated with FLT3-ITD signalling.
Project description:Examination of gene expression patterns in lineage negative FLT3-ITDâ and pMIG-transduced BM cells via microarray study. We performed a global mRNA profiling analysis of murine Linâ FLT3-ITD+ cells compared to empty-vector controls, purified 48h after transduction. We examined association patterns of FLT3-ITD and pMIG cells and identified a specific gene expression signature associated with FLT3-ITD signalling. Total RNA obtained from isolated lineage negative BM cells subjected to 48h of FLT3-ITD signalling compared to empty vector control.
Project description:Purpose: Analysis of downstream pathways activated by NPMc+ and Flt3-ITD oncogenes in preleukemic hematopoietic stem cells (HSCs). Methods: RNA extracted and processed from MxCRE, Flt3-ITD and NPMc+/Flt3-ITD FACS sorted HSCs Results: These data demonstrate that NPMc+ expression in Flt3-ITD HSCs promote a transcriptional program that supports both self-renewal and quiescence.
Project description:Effectively targeting leukemia-initiating cells (LIC) in FLT3-internal-tandem-duplication (ITD)-mutated acute myeloid leukemia (AML) remains a crucial goal for achievement of cure. FLT3 tyrosine kinase inhibitors (TKI) have limited impact as single agents and have thus far been unable to eradicate LIC enriched in the CD34+CD38- bone marrow compartment and protected by contact with niche cells.Using primary AML samples in vitro as well as in an in vivo xenograft model, we investigated whether combining the novel FLT3-selective TKI crenolanib with the hypomethylating agent azacitidine (AZA) can eliminate LIC in FLT3-ITD+ AML and determined whether efficacy of this combination is dependent on coexisting genetic mutations in DNMT3A, NPM1 and TET2. Our data show that crenolanib as a single agent was unable to target FLT3-ITD+ LIC in contact with niche cells while the addition of AZA overcame stromal protection and resulted in dramatically reduced clonogenic capacity of FLT3-ITD+ LIC in vitro as well as severely impaired engraftment capacity of FLT3-ITD+ LIC in NSG mice. Strikingly, FLT3-mutated AML samples harboring concurrent TET2 mutations were completely resistant to crenolanib as a single agent. Mutations in DNMT3A or NPM1 had no influence on response to crenolanib while DNMT3A mutations conferred increased sensitivity of FLT3-ITD+ LIC to AZA. Our data suggest that response to crenolanib or AZA as single agents in FLT3-ITD+ AML is highly dependent on coexisting mutations in epigenetic regulators. However, the combination of AZA + crenolanib effectively eliminated FLT3-ITD+ LIC irrespective of additional mutations in NPM1, DNMT3A or TET2.
Project description:We performed genome-wide DNaseI hypersensitive site in FLT3-ITD and WT patient samples. We report corresponding gene expression, promoter methylation patterns of differential DHSs as well as differentially occupied TF binding motifs using surrounding DNAseI cut profiles. We examined association patterns of FLT3 ITD and WT AMLs and found that FLT3-ITD signaling is associated with common gene expression and chromatin signature. Examination of DNA methylation patterns in FLT3 ITD and WT AML via microarray study.
Project description:We performed genome-wide DNaseI hypersensitive site in FLT3-ITD and WT patient samples. We report corresponding gene expression, promoter methylation patterns of differential DHSs as well as differentially occupied TF binding motifs using surrounding DNAseI cut profiles. We examined association patterns of FLT3 ITD and WT AMLs and found that FLT3-ITD signaling is associated with common gene expression and chromatin signature. Examination of gene expression patterns in FLT3 ITD and WT AML via microarray study.
Project description:Transcriptional profiling of murine bone marrow c-kit+, Sca-1+ lineage neative (KSL) cells from p21CDKN1a-/- and p21+/+ overexpressing Flt3/ITD. The goal was to determine the effect on global gene expression by loss of p21 in Flt3/ITD transformed KSL cells Internal tandem duplication (ITD) mutations in the Flt3 gene (Flt3-ITD) are associated with poor prognosis in patients with acute myeloid leukemia (AML). Few inhibitors of Flt3-ITD are effective against Flt3-ITD+ AML due to the development of drug-resistance. In this study, we demonstrate that Flt3-ITD activates a novel pathway involving p21Cdkn1a (p21) and pre-B cell leukemia transcription factor 1 (Pbx1) that attenuates Flt3-ITD cell proliferation and is involved in the development drug resistance. Flt3-ITD up-regulated p21 expression in mouse bone marrow c-kit+-Sca-1+-Lin- (KSL) cells and in Ba/F3 cells. Loss of p21 expression enhanced growth factor-independent proliferation and sensitivity to cytarabine as a consequence of enriching the S+G2/M phase population concomitant with a significant increase in the expression of Pbx1, but not Evi-1, in Flt3-ITD+ cells. This enhancement of cell proliferation by loss of p21 was partially abrogated when Pbx1 expression was silenced in Flt3-ITD+ primary bone marrow colony-forming cells (CFCs) and Ba/F3 cells. Antagonizing Flt3-ITD using AC220, a selective inhibitor of Flt3-ITD, decreased the expression of p21, coincident with the up-regulation of Pbx1 mRNA and a rapid decline in the number of viable Flt3-ITD+ Ba/F3 cells, however the cells eventually became refractory to AC220. Overexpressing p21 in Flt3-ITD+ Ba/F3 cells delayed the emergence of cells refractory to AC220, whereas silencing p21 accelerated their development. These data demonstrate that Flt3-ITD is capable of inhibiting the proliferation of Flt3-ITD+ cells through the p21/Pbx1 axis and that antagonizing Flt3-ITD contributes to the subsequent development of cells refractory to Flt3-ITD inhibitor by disrupting p21 expression. biological replicates: 3 KSL cell replicates overexpressing ITD-Flt3 from p21+/+ and p21-/- cells, 1 KSL cell replicate from p21+/+ and p21-/- cells
Project description:Transcriptional profiling of murine bone marrow c-kit+, Sca-1+ lineage neative (KSL) cells from p21CDKN1a-/- and p21+/+ overexpressing Flt3/ITD. The goal was to determine the effect on global gene expression by loss of p21 in Flt3/ITD transformed KSL cells Internal tandem duplication (ITD) mutations in the Flt3 gene (Flt3-ITD) are associated with poor prognosis in patients with acute myeloid leukemia (AML). Few inhibitors of Flt3-ITD are effective against Flt3-ITD+ AML due to the development of drug-resistance. In this study, we demonstrate that Flt3-ITD activates a novel pathway involving p21Cdkn1a (p21) and pre-B cell leukemia transcription factor 1 (Pbx1) that attenuates Flt3-ITD cell proliferation and is involved in the development drug resistance. Flt3-ITD up-regulated p21 expression in mouse bone marrow c-kit+-Sca-1+-Lin- (KSL) cells and in Ba/F3 cells. Loss of p21 expression enhanced growth factor-independent proliferation and sensitivity to cytarabine as a consequence of enriching the S+G2/M phase population concomitant with a significant increase in the expression of Pbx1, but not Evi-1, in Flt3-ITD+ cells. This enhancement of cell proliferation by loss of p21 was partially abrogated when Pbx1 expression was silenced in Flt3-ITD+ primary bone marrow colony-forming cells (CFCs) and Ba/F3 cells. Antagonizing Flt3-ITD using AC220, a selective inhibitor of Flt3-ITD, decreased the expression of p21, coincident with the up-regulation of Pbx1 mRNA and a rapid decline in the number of viable Flt3-ITD+ Ba/F3 cells, however the cells eventually became refractory to AC220. Overexpressing p21 in Flt3-ITD+ Ba/F3 cells delayed the emergence of cells refractory to AC220, whereas silencing p21 accelerated their development. These data demonstrate that Flt3-ITD is capable of inhibiting the proliferation of Flt3-ITD+ cells through the p21/Pbx1 axis and that antagonizing Flt3-ITD contributes to the subsequent development of cells refractory to Flt3-ITD inhibitor by disrupting p21 expression.
Project description:We performed genome-wide DNaseI hypersensitive site in FLT3-ITD and WT patient samples. We report corresponding gene expression, promoter methylation patterns of differential DHSs as well as differentially occupied TF binding motifs using surrounding DNAseI cut profiles. We examined association patterns of FLT3 ITD and WT AMLs and found that FLT3-ITD signaling is associated with common gene expression and chromatin signature. Examination of Runx1 binding sites in FLT3 ITD AML.
Project description:We performed genome-wide DNaseI hypersensitive site in FLT3-ITD and WT patient samples. We report corresponding gene expression, promoter methylation patterns of differential DHSs as well as differentially occupied TF binding motifs using surrounding DNAseI cut profiles. We examined association patterns of FLT3 ITD and WT AMLs and found that FLT3-ITD signaling is associated with common gene expression and chromatin signature. Examination of genome-wide DNaseI hypersensitivite sites in FLT3 ITD and WT AML.
Project description:We performed genome-wide DNaseI hypersensitive site in FLT3-ITD and WT patient samples. We report corresponding gene expression, promoter methylation patterns of differential DHSs as well as differentially occupied TF binding motifs using surrounding DNAseI cut profiles. We examined association patterns of FLT3 ITD and WT AMLs and found that FLT3-ITD signaling is associated with common gene expression and chromatin signature.