Project description:To identify the role of N-MYC in transcriptional regulation in human inv(16) AML, we conducted conducted CUT&Tag analysis for N-MYC and H3K27AC in ME-1 cells
Project description:Cancer cells maintain a sensitive balance between growth-promoting oncogenes and apoptosis inhibitors. We show that WT RUNX1 is required for survival of t(8;21)-Kasumi-1 and inv(16)-ME-1 AML cell lines. The malignant AML phenotype is sustained by a delicate AML1-ETO/RUNX1 balance that involves competition for common DNA binding sites regulating a subset of AML1-ETO/RUNX1 targets.
Project description:Cancer cells maintain a sensitive balance between growth-promoting oncogenes and apoptosis inhibitors. We show that WT RUNX1 is required for survival of t(8;21)-Kasumi-1 and inv(16)-ME-1 AML cell lines. The malignant AML phenotype is sustained by a delicate AML1-ETO/RUNX1 balance that involves competition for common DNA binding sites regulating a subset of AML1-ETO/RUNX1 targets.
Project description:Acute myeloid leukemia (AML) harboring inv(16)(p13q22) expresses high levels of miR-126. Here we show that the CBFB-MYH11 (CM) fusion gene upregulates miR-126 expression through aberrant miR-126 transcription and perturbed miR-126 biogenesis via the HDAC8/RAN-XPO5-RCC1 axis. Aberrant miR-126 upregulation promotes survival of leukemia-initiating progenitors and is critical for initiating and maintaining CM-driven AML. We show that miR-126 enhances MYC activity through the SPRED1/PLK2-ERK-MYC axis. Notably, genetic deletion of miR-126 significantly reduced AML rate and extended survival in CM knock-in mice. Therapeutic depletion of miR-126 with an anti-miR-126 (miRisten) inhibited AML cell survival, reduced leukemia burden and leukemia stem cell (LSC) activity in inv(16) AML murine and xenograft models. Combination of miRisten with chemotherapy further enhanced the anti-leukemia and anti-LSC activity. Overall, this study provides molecular insights for the mechanism and impact of miR-126 dysregulation in leukemogenesis and highlights the potential of miR-126 depletion as a new therapeutic approach for inv(16) AML.
Project description:Cancer cells maintain a sensitive balance between growth-promoting oncogenes and apoptosis inhibitors. We show that WT RUNX1 is required for survival of t(8;21)-Kasumi-1 and inv(16)-ME-1 AML cell lines. The malignant AML phenotype is sustained by a delicate AML1-ETO/RUNX1 balance that involves competition for common DNA binding sites regulating a subset of AML1-ETO/RUNX1 targets. Genome expression was profiled after performing knockdown of RUNX1 and AML1-ETO in Kasumi-1 cells using specific siRNA-oligo nucleotides, and analyzed using Affymetrix Gene 1.0 ST arrays.
Project description:Cancer cells maintain a sensitive balance between growth-promoting oncogenes and apoptosis inhibitors. We show that WT RUNX1 is required for survival of t(8;21)-Kasumi-1 and inv(16)-ME-1 AML cell lines. The malignant AML phenotype is sustained by a delicate AML1-ETO/RUNX1 balance that involves competition for common DNA binding sites regulating a subset of AML1-ETO/RUNX1 targets. Genomewide sequencing data is included herein: Transcription factors RUNX1 c-terminus and n-terminus which is shared with AML1-ETO were profiled independently), AML1-ETO and AP4 were profiled using ChIP-Seq in Kasumi-1 cells, as well as control ChIP-Seq experiments of non immune serum. Two replicates were performed for each transcription factor profiling and control experiment.
Project description:The hematopoietic system is maintained throughout life by hematopoietic stem cells that are capable of differentiation to all hematopoietic lineages. An intimate balance between self-renewal, differentiation, and quiescence is required to maintain hematopoiesis. Disruption of this balance can result in hematopoietic malignancy, including acute myeloid leukemia (AML). FBXO9, from the F-box ubiquitin E3 ligases, is down-regulated in patients with AML compared to normal bone marrow. FBXO9 is a substrate recognition component of the Skp1-Cullin-F-box (SCF)-type E3 ligase complex. FBXO9 is highly expressed in hematopoietic stem and progenitor populations, which contain the tumor-initiating population in AML. In AML patients, decrease in FBXO9 expression is most pronounced in patients with the inversion of chromosome 16 (Inv(16)), a rearrangement that generates the transcription factor fusion gene, CBFB-MYH11. To study FBXO9 in malignant hematopoiesis, we generated a conditional knockout mouse model using a novel CRISPR/Cas9 strategy. Our data shows that deletion of Fbxo9 in mice expressing Cbfb-MYH11 leads to markedly accelerated and aggressive leukemia development. In addition, we find loss of FBXO9 leads to increased proteasome expression and tumors are more sensitive to bortezomib suggesting that FBXO9 expression may predict patient response to bortezomib treatment.
Project description:Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) harboring both inv(3)/t(3;3) and monosomy 7 (-7) are highly aggressive myeloid cancers whose molecular pathogenesis and therapeutic vulnerability remain elusive. High throughput drug screens, CUT&Tag/RNA sequence and functional assays using human MDS/AML cells revealed that EZH2 inhibitors efficiently induce apoptosis preferentially in MDS/AML with inv(3)/t(3;3) and -7 through activation of GADD45γ-p38-p53 axis. EVI1 activated in 3q-rearranged MDS/AML was responsible for GADD45γ silencing by direct binding to its consensus sequence within GADD45γ promoter and recruitment of PRC2 complex via interaction with EZH2, which can be therapeutically targeted by EZH2 inhibition. MDS/AML with inv(3)/t(3;3) and -7 showed preferential sensitivity to EZH2 inhibition in both mouse model and patient samples. Thus, MDS/AML cells with inv(3)/t(3;3) and -7 possess apoptosis evasion mechanism through EVI1-PRC2-mediated repression of GADD45γ-p38-p53 axis, which is a potential therapeutic vulnerability in MDS/AML patients with these high-risk cytogenetic lesions.
Project description:inv(16)/Tet2-/- GMPs (Lin- Sca1- ckit+ CD41- FcgR+ CD150-) were FACS sorted as described in Supplementary Information (Reckzeh, K et al 2020) TET2 deficiency cooperates with CBFB-MYH11 to induce acute myeloid leukemia and represents an early leukemogenic event. Reckzeh, K et al.