Project description:Histone acetylation, including acetylated H3K14 (H3K14ac), is generally linked to gene activation. Monomethylated histone H3 lysine 4 (H3K4me1), together with other gene-activating marks, denotes active genes. In contrast to usual gene-activating functions of H3K14ac and H3K4me1, we here show that the dual histone modification mark H3K4me1-H3K14ac is recognized by ZMYND8 (also called RACK7) and functions to counteract gene expression. We identified ZMYND8 as a transcriptional corepressor of the H3K4 demethylase JARID1D. ZMYND8 antagonizes the expression of metastasis-linked genes, and its knockdown increases the cellular invasiveness in vitro and in vivo. The plant homeodomain (PHD) and Bromodomain cassette in ZMYND8 mediates the combinatorial recognition of H3K4me1-H3K14ac and H3K4me0-H3K14ac by ZMYND8. These findings uncover an unexpected role for the signature H3K4me1-H3K14ac in attenuating gene expression and reveal a previously unknown metastasis-suppressive epigenetic mechanism in which ZMYND8's PHD-Bromo cassette couples H3K4me1-H3K14ac with repression of metastasis-linked genes. i) ChIP-Seq data of ZMYND8, JARID1D, H3K4me1, H3K14ac, H3K4me3, and H3K27me3 in normal DU145 cells. ii) ChIP-Seq data of H3K4me1 and H3K4me3 in shLuciferase-, shJARID1D-, or shZMYND8-treated DU145 cells. iii) RNA-Seq data in shLuciferase-, shJARID1D-, or shZMYND8-treated DU145 cells.
Project description:OBJECTIVE: MEIS1, a HOX cofactor, collaborates with multiple HOX and NUP98-HOX fusion proteins to accelerate the onset of acute myeloid leukemia (AML) through largely unknown molecular mechanisms. MATERIALS AND METHODS: To further resolve these mechanisms, we conducted a structure-function analysis of MEIS1 and gene-expression profiling, in the context of NUP98-HOXD13 (ND13) leukemogenesis. RESULTS: We show, in a murine bone marrow transplantation model, that the PBX-interaction domain, the homeodomain, and the C-terminal domain of MEIS1, are all required for leukemogenic collaboration with ND13. In contrast, the N-terminal domain of MEIS1 is dispensable for collaboration with ND13, but is required for Flt3 upregulation, indicating additional roles for MEIS1 in induction of leukemia independent of alterations in Flt3 expression. Gene-expression profiling of a cloned ND13 preleukemic cell line transduced with wild-type or Meis1 mutant forms revealed deregulation of multiple genes, including a set not previously implicated as MEIS1 targets. Chromatin immunoprecipitation revealed the in vivo occupancy of MEIS1 on regulatory sequences of Trib2, Flt3, Dlk1, Ccl3, Ccl4, Pf4, and Rgs1. Furthermore, engineered overexpression of Trib2 complements ND13 to induce AML while Ccl3 potentiates the repopulating ability of ND13. CONCLUSION: This study shows that Meis1-induced leukemogenesis with ND13 can occur in the absence of Flt3 upregulation and reveals the existence of other pathways activated by MEIS1 to promote leukemia. Establishment of pre-leukemic bone marrow cell lines following transduction with ND13 have been previously described (Pineault, Abramovich et al. 2005). In brief, lines were established from BM cells previously treated with 5-fluorouracil (5-FU) from (C57Bl/6Ly-Pep3b x C3H/HeJ) F1 (PepC3) (Ly5.1+/Ly5.2+) mice freshly transduced with the ND13-GFP or ND13pac virus and maintained in liquid culture. To generate ND13+Meis1 or ND13+Meis1 mutant BM cell lines, the ND13 BM cells were transduced by co-cultivation on irradiated (4,000 cGy) E86 producers for Meis1-YFP (or Meis1 mutant forms), respectively, for a period of 2 days in the presence of 5 µg/ml of protamine sulfate. Three independent experiments were performed for each of the four different conditions included in the study.
Project description:Histone modifcations and CTCF binding at the c-myb locus were compared in cell lines with c-myb expressing, which are myeloblatic M1 cells and leukemia cells with virus integration, VS. M1 cells without c-myb expression induced by IL-6. Distribution of active histone marks at the c-myb gene and the upstream regions are associated with active c-myb transcription. The enrichment of all of these active histone marks decreased with differentiation-induced down-regulation of c-myb, but increased and spread in tumor cells. ChIP-on-chip from murine myeloid cell line M1 and virus-induced myeloid leukemia cell lines for H3K4me3, H3K9/14ac, H3K4me1, H3K27me3, H3K9me3 and CTCF
Project description:Leukemia initiating cells (LICs) of acute myeloid leukemia (AML) may arise from self-renewing hematopoietic stem cells (HSCs) and from committed progenitors. However, it remains unclear how leukemia-associated oncogenes instruct LIC formation from cells of different origins and if differentiation along the normal hematopoietic hierarchy is involved. Here, using murine models with the driver mutations MLL-AF9 or MOZ-TIF2, we found that regardless of the transformed cell types, myelomonocytic differentiation to the granulocyte macrophage progenitor (GMP) stage is critical for LIC generation. Blocking myeloid differentiation through disrupting the lineage-restricted transcription factor C/EBPa eliminates GMPs, blocks normal granulopoiesis, and prevents AML development. In contrast, restoring myeloid differentiation through inflammatory cytokines “rescues” AML transformation. Our findings identify myeloid differentiation as a critical step in LIC formation and AML development, thus guiding new therapeutic approaches. Examination of chromatin accessibility in Cebpa knock-out and control conditions.
Project description:Methylation of histone 3 on lysine 79 (H3K79) is broadly associated with active gene expression in eukaryotes, and the H3K79 methyltransferase DOT1L is indispensable for specific leukemia subtypes like those with MLL-translocations. We found that suppression of the histone deacetylase SIRT1 rescued MLL-AF9 leukemia cells from their dependence on DOT1L. We show that upon DOT1L inhibition, SIRT1 is required for the acquisition of a repressive chromatin state consistent with facultative heterochromatin around MLL-AF9 target genes in leukemia and other genes possess an H3K79me2(hi), H3K9ac(hi), H3K9me2(low) histone modification profile in normal hematopoietic stem and progenitor cells. Examination of histone modifications and a chromatin modifier with and without drug treatment and RNA interference.
Project description:Hver2.1.1 microarrays containing ~15,000 genes were used to characterize the gene expression profiles of Vg9/Vd2 T cells upon 72h stimulation with HMB-PP in the presence of IL-2, IL-4, or IL-21.
Project description:Epigenetic mechanisms including histone modifications have emerged as important factors influencing cell fate determination. The functional role of H3K4 methylation, however, remains largely unclear in the maintenance and differentiation of hematopoietic stem/progenitor cells (HSC/HPCs). Here we show that DPY30, a shared core subunit of the SET1/MLL family methyltransferase complexes and a facilitator of their H3K4 methylation activity, is important for ex vivo proliferation and differentiation of human CD34+ HPCs. DPY30 promotes HPC proliferation by directly regulating the expression of genes critical for cell proliferation. Interestingly, while DPY30 knockdown (KD) in HPCs impaired their differentiation into the myelomonocytic lineage, it potently promoted hemoglobin production and affected the kinetics of their differentiation into the erythroid lineage. In an in vivo model, we show that morpholino-mediated dpy30 KD resulted in severe defects in the development of the zebrafish hematopoietic system, which could be partially rescued by co-injection of dpy30 mRNA. Taken together, our results establish a critical role of DPY30 in the proliferation and appropriate differentiation of hematopoietic progenitor cells as well as in animal hematopoiesis. Finally, we also demonstrate a crucial role of DPY30 in the growth of several MLL1-fusion-mediated leukemia cell lines. Total RNAs from control (scr) or knockdown (hD2, hD5) cells before and after culturing under condition promoting myelomonocytic differentiation were subjected to Illumina microarray analyses.
Project description:The molecular pathways mediating unlimited self-renewal and alleged drug resistant properties that are believed to be key for maintenance and re-initiation of leukemia during relapse are largely unexplored area. To gain further insights into the potential pathways responsible for the conversion and establishment of leukemic stem cells (LSC), we molecularly dissected and compared the cell populations enriched in pre-LSC and LSC. In this model, pre-LSC were identified as early transduced primary cells carrying the initiating event and endowed with the ability to induce leukemia in vivo with a long latency. LSC were defined as leukemic cells harvested from primary mice transplanted with pre-LSC that had then acquired additional events and were capable of inducing leukemia in secondary mice with a very short latency. <br><br>Pre-LSC were generated by transformation of cKit+ purified cells derived from mouse bone marrow with MLL-ENL retrovirus and subjected to several rounds of replating in methylcellulose. A cell line (pre-LSC bulk population) was subsequently generated and injected into mice. Cells derived from a leukemic mouse were used to generate the LSC cell line (LSC bulk population). Pre-LSC and LSC bulk populations and their clonal deriviatives were used in microarray experiments to help identify key events which convert pre-LSC to LSC.
Project description:Cytotoxic CD8+ T cells can effectively kill target cells by producing cytokines, chemokines and granzymes. Expression of these effector molecules is however highly divergent, and tools that identify and pre-select potent killer cells are lacking. Human CD8+ T cells can be divided into IFNGand IL-2 producing cells. Unbiased RNA-sequencing and proteomics analysis on cytokine-producing fixed CD8+ T cells revealed that IL-2+ T cells produce helper cytokines, and that IFNG+ T cells produce cytotoxic molecules. IFNG+ cytotoxic T cells expressed the surface marker CD29 already prior to stimulation. CD29 also marked T cells with cytotoxic gene expression from different tissues in single-cell RNA-sequencing data. Notably, the cytotoxic features of CD29+ T cells were maintained during cell culture, suggesting a stable phenotype. Pre-selecting CD29-expressing MART1 TCR-engineered T cells potentiated the killing of target cells. We therefore propose that selecting for CD29+ T cells could boost the anti-tumoral activity of T cell therapeutics.