Inhibitors of LSD1 target demethylase-independent activity to induce differentiation in acute myeloid leukemia [ChIP-Seq: histone modifications]
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ABSTRACT: To determine whether changes in histone modifications directly correlate with changes in transcription, THP1 AML cells were treated with a potent and selective LSD1 inhibitor (OG86) and then subjected to concomitant RNA sequencing (RNAseq) and ChIP sequencing (ChIPseq) for monomethyl-, dimethyl- and trimethyl histone H3 modifications.
Project description:To determine whether changes in histone modifications directly correlate with changes in transcription, THP1 AML cells were treated with a potent and selective LSD1 inhibitor (OG86) and then subjected to concomitant RNA sequencing (RNAseq) and ChIP sequencing (ChIPseq) for monomethyl-, dimethyl- and trimethyl histone H3 modifications.
Project description:To determine whether changes in histone modifications directly correlate with changes in transcription, THP1 AML cells were treated with a potent and selective LSD1 inhibitor (OG86, 250nM) and then subjected to concomitant RNA sequencing (RNAseq) and ChIP sequencing (ChIPseq) for histone acetylation modifications, RCOR1, SPI1 and MLL4.
Project description:To identify genomic binding regions, THP1 AML cells were subjected to ChIP sequencing (ChIPseq) using anti-LSD1, MYB or GFI1 antibodies.
Project description:Lysine-specific demethylase 1 (LSD1) is an epigenetic enzyme that oxidatively cleaves methyl groups from monomethyl and dimethyl Lys4 of histone H3 (H3K4Me1, H3K4Me2) and can contribute to gene silencing. This study describes the design and synthesis of analogs of a monoamine oxidase antidepressant, phenelzine, and their LSD1 inhibitory properties. A novel phenelzine analog (bizine) containing a phenyl-butyrylamide appendage was shown to be a potent LSD1 inhibitor in vitro and was selective versus monoamine oxidases A/B and the LSD1 homolog, LSD2. LSD1 inhibitor bizine was found to be effective at modulating bulk histone methylation in cancer cells, and ChIP-seq experiments revealed a statistically significant overlap in the H3K4 methylation pattern of genes affected by bizine and those altered in LSD1-/- cells. Treatment of two cancer cell lines, LNCaP and H460 with bizine conferred a reduction in proliferation rate, and bizine showed additive to synergistic effects on cell growth when used in combination with two out of five HDAC inhibitors tested. Moreover, neurons exposed to oxidative stress were protected by the presence of bizine, suggesting potential applications in neurodegenerative disease.
Project description:Using a mouse model of human MLL-AF9 leukemia, we identified the lysine-specific demethylase KDM1A (LSD1 or AOF2) as an essential regulator of leukemia stem cell (LSC) potential. KDM1A acts at genomic loci bound by MLL-AF9 to sustain expression of the associated oncogenic program, thus preventing differentiation and apoptosis. In vitro and in vivo pharmacologic targeting of KDM1A using tranylcypromine analogues active in the nanomolar range phenocopied Kdm1a knockdown in both murine and primary human AML cells exhibiting MLL translocations. By contrast, the clonogenic and repopulating potential of normal hematopoietic stem and progenitor cells was spared. Our data establish KDM1A as a key effector of the differentiation block in MLL leukemia which may be selectively targeted to therapeutic effect. To investigate the effects of Kdm1a KD on histone modifications, we performed chromatin immunoprecipitation followed by next-generation sequencing (ChIP-Seq) in control and Kdm1a KD MLL-AF9 AML cells for dimethyl-H3K4 and dimethyl-H3K9, as well as for trimethyl-H3K4 and trimethyl-H3K9. Dimethyl-H3K4 and dimethyl-H3K9 are targeted for demethylation by KDM1A. For each of these histone modifications, we compared the mean ChIP-Seq signal across and around protein coding genes bound by the MLL-AF9 oncoprotein (Bernt et al., 2011) with the mean signal from genes not bound by MLL-AF9 expressed at high, middle or low levels.
Project description:Biochemical crosstalk between two or more histone modifications is often observed in epigenetic enzyme regulation but its functional significance in cells has been difficult to discern. Prior enzymatic studies have revealed that Lys14 acetylation of histone H3 can inhibit Lys4 demethylation by lysine specific demethylase 1 (LSD1). Here we have engineered a mutant form of LSD1, Y391K, which renders the nucleosome demethylase activity of LSD1 insensitive to Lys14 acetylation. Y391K LSD1 knockin cells show increased repression of a set of genes associated with cellular adhesion. Chromatin profiling revealed that the cis-regulatory regions of these silenced genes display a higher level of H3 Lys14 acetylation than the baseline in unedited, parental cells. Y391K LSD1 knockin cells show diminished H3 mono-methyl Lys4 in the vicinity of these silenced genes, consistent with a role for enhanced LSD1 demethylase activity in these regions. These findings illuminate the functional consequences of disconnecting histone modification crosstalk for a key epigenetic enzyme in gene and chromatin regulation.
Project description:Biochemical crosstalk between two or more histone modifications is often observed in epigenetic enzyme regulation but its functional significance in cells has been difficult to discern. Prior enzymatic studies have revealed that Lys14 acetylation of histone H3 can inhibit Lys4 demethylation by lysine specific demethylase 1 (LSD1). Here we have engineered a mutant form of LSD1, Y391K, which renders the nucleosome demethylase activity of LSD1 insensitive to Lys14 acetylation. Y391K LSD1 knockin cells show increased repression of a set of genes associated with cellular adhesion. Chromatin profiling revealed that the cis-regulatory regions of these silenced genes display a higher level of H3 Lys14 acetylation than the baseline in unedited, parental cells. Y391K LSD1 knockin cells show diminished H3 mono-methyl Lys4 in the vicinity of these silenced genes, consistent with a role for enhanced LSD1 demethylase activity in these regions. These findings illuminate the functional consequences of disconnecting histone modification crosstalk for a key epigenetic enzyme in gene and chromatin regulation.
Project description:Here we describe that lysine-specific demethylase 1 (Lsd1/KDM1a), which demethylates histone H3 on LysM-bM-^@M-^I4 or LysM-bM-^@M-^I9 (H3K4/K9), is an indispensible epigenetic governor of hematopoietic differentiation. Integrative genomic analysis in primary hematopoietic cells, combining global occupancy of Lsd1, genome-wide analysis of its histone substrates H3K4 mono- and di-methylation and gene expression profiling, reveals that Lsd1 represses hematopoietic stem and progenitor cell (HSPC) gene expression programs during hematopoietic differentiation. We found that Lsd1 function was not restricted to transcription start sites, but is also critical at enhancers. Loss of Lsd1 at these sites was associated with increased H3K4me1 and H3K4me2 methylation levels on HSPC genes and their derepression. Failure to fully silence HSPC genes compromised differentiation of hematopoietic stem cells and mature blood cell lineages. Our data indicate that Lsd1-mediated concurrent repression of enhancer and promoter activity of stem and progenitor cell genes is a pivotal epigenetic mechanism required for proper hematopoietic maturation. To identify direct target genes of Lsd1 in myeloid cells we mapped global occupancy of Lsd1 in 32D granuolocytic progenitor cells and compared H3K4me1/me2/me3 and H3K27ac histone modifications in Lsd1fl/fl (wild type) vs. Lsd1fl/f Mx1Cre (knockout) Gr1dim Mac1 granuolocytic progenitor cells.
Project description:The Nitroreductase NfsB (NTR) prodrug of an LSD1 inhibitor is inactive in wild-type THP1 cells, but the prodrug gets activated in the LSD1 inhibitor by the NTR in NTR-expressing THP1 cells (THP1-NTR+). Cell-type specific inhibition of LSD1 in THP1-NTR+ cells with a NTR prodrug is shown with the expression data of the two cell lines, THP1-wt and THP1-NTR+. Data for the LSD1 inhibitor and a negative control with both cell lines are included.