Project description:This SuperSeries is composed of the following subset Series: GSE27714: Enhancer Decommissioning by LSD1 During Embryonic Stem Cell Differentiation (expression) GSE27841: Enhancer Decommissioning by LSD1 During Embryonic Stem Cell Differentiation (ChIP-seq) Refer to individual Series
Project description:We treated the T-ALL cell line MOLT4 with a novel LSD inhibitor and performed ChIP-seq analysis using anti-histoneH3K27ac antibody to assess the enhancer function.
Project description:LSD1 is a demethylase of histone modification H3k4me1 and H3K4me2. We have developed novel LSD1 inhibitors (NCD25 and NCD38) and found that they are effective to myelodysplastic syndromes and leukemia cells. To understand what mechanisms are affected by these compounds, we employed gene expression profiling analyses. Gene expression profiling data were obtained from HEL, MDS-L, or CMK11-5 cells treated with DMSO (control), NCD25, or NCD38 and compared each other. Expression of eleven transcriptional factors (GFI1, CEBPA, SPI1, MNDA, TAL1, GATA1, NFE2, RXRA, HOXA9, GATA2, and PBX1) was reconfirmed by q-PCR with the same samples. Gene expression of leukemia cells was measured after 48 hours incubation with or without LSD1 inhibitors. Five independent experiments were performed using 3 cell lines (HEL, MDS-L and CMK11-5) and 2 drugs (NCD38 and NCD25).
Project description:The histone de-methylase LSD1 is over-expressed in different haematological tumours, like AML, where it sustains carcinogenesis by promoting the clonogenic potential of leukemic stem cells. Emerging as a promising epigenetic target for the treatment of these tumour types, various LSD1 inhibitors have been developed in the last years, despite their mechanism of action in cancer cells is often not fully clarified. In this study, we characterized a novel mode of action of the inhibitors MC2580 and DDP-38003 and demonstrated that they trigger myeloid differentiation of AML by down-regulating GSE1 protein, a LSD1 interactor on chromatin. By studying the phenotypic effects of GSE1 depletion in NB4 cells, we observed a strong decrease of cell proliferation in vitro, and of tumour growth in vivo. Comparing the transcriptomic changes induced by GSE1 knock-down with those elicited by LSD1 pharmacological inhibition, we found a common set of genes up-regulated and linked with immune response and cytokine-mediated signalling. Mechanistically, we found that several promoters of these genes are bound by both LSD1 and GSE1 at basal state and that GSE1 binding is strongly reduced upon LSD1 inhibition, as a consequence of its reduced expression. By describing for the first time that LSD1-GSE1 interaction on chromatin enforces the silencing of genes linked to myeloid differentiation and by highlighting that this interaction can be overcome by LSD1 inhibitors, our study offers a new perspective on the use of these compounds to trigger differentiation in leukaemia through GSE1 modulation.
Project description:The histone de-methylase LSD1 is over-expressed in different haematological tumours, like AML, where it sustains carcinogenesis by promoting the clonogenic potential of leukemic stem cells. Emerging as a promising epigenetic target for the treatment of these tumour types, various LSD1 inhibitors have been developed in the last years, despite their mechanism of action in cancer cells is often not fully clarified. In this study, we characterized a novel mode of action of the inhibitors MC2580 and DDP-38003 and demonstrated that they trigger myeloid differentiation of AML by down-regulating GSE1 protein, a LSD1 interactor on chromatin. By studying the phenotypic effects of GSE1 depletion in NB4 cells, we observed a strong decrease of cell proliferation in vitro, and of tumour growth in vivo. Comparing the transcriptomic changes induced by GSE1 knock-down with those elicited by LSD1 pharmacological inhibition, we found a common set of genes up-regulated and linked with immune response and cytokine-mediated signalling. Mechanistically, we found that several promoters of these genes are bound by both LSD1 and GSE1 at basal state and that GSE1 binding is strongly reduced upon LSD1 inhibition, as a consequence of its reduced expression. By describing for the first time that LSD1-GSE1 interaction on chromatin enforces the silencing of genes linked to myeloid differentiation and by highlighting that this interaction can be overcome by LSD1 inhibitors, our study offers a new perspective on the use of these compounds to trigger differentiation in leukaemia through GSE1 modulation.
Project description:Transcription factors and chromatin modifiers play important roles in programming and reprogramming of cellular states during development. Much is known about the role of these regulators in gene activation, but relatively little is known about the critical process of enhancer silencing during differentiation. Here we show that the H3K4/K9 histone demethylase LSD1 plays an essential role in decommissioning enhancers during differentiation of embryonic stem cells (ESCs). LSD1 occupies enhancers of active genes critical for control of ESC state. However, LSD1 is not essential for maintenance of ESC identity. Instead, ESCs lacking LSD1 activity fail to fully differentiate and ESC-specific enhancers fail to undergo the histone demethylation events associated with differentiation. At enhancers, LSD1 is a component of the NuRD complex, which contains additional subunits that are necessary for ESC differentiation. We propose that the LSD1-NuRD complex decommissions enhancers of the pluripotency program upon differentiation, which is essential for complete shutdown of the ESC gene expression program and the transition to new cell states. This represents the expression part of the study.
Project description:Transcription factors and chromatin modifiers play important roles in programming and reprogramming of cellular states during development. Much is known about the role of these regulators in gene activation, but relatively little is known about the critical process of enhancer silencing during differentiation. Here we show that the H3K4/K9 histone demethylase LSD1 plays an essential role in decommissioning enhancers during differentiation of embryonic stem cells (ESCs). LSD1 occupies enhancers of active genes critical for control of ESC state. However, LSD1 is not essential for maintenance of ESC identity. Instead, ESCs lacking LSD1 activity fail to fully differentiate and ESC-specific enhancers fail to undergo the histone demethylation events associated with differentiation. At enhancers, LSD1 is a component of the NuRD complex, which contains additional subunits that are necessary for ESC differentiation. We propose that the LSD1-NuRD complex decommissions enhancers of the pluripotency program upon differentiation, which is essential for complete shutdown of the ESC gene expression program and the transition to new cell states. This is the ChIP-seq part of the study.
Project description:Pharmacological small molecules that target fetal hemoglobin (HbF) repressors serve as potent, cost-effective, and accessible therapeutic strategies to β-globinopathies such as sickle cell disease (SCD). LSD1 inhibition has been shown to induce HbF levels both in vitro and in vivo. However, all potent LSD1 inhibitors in HbF induction in vivo are covalent irreversible compounds, which can cause some adverse effects. In this study, we utilized structure-aided drug design based on the scaffold of a reversible LSD1 inhibitor GSK-690, and developed potent new reversible LSD1 inhibitors that induce robust γ-globin expression in human primary erythroid differentiation culture. Moreover, in a transgenic mouse model of SCD, oral administration of the novel LSD1 inhibitors induces significant elevation of HbF levels and alleviates the disease pathologies resulted from SCD. In addition, combined treatment of an BRD4 degrader, BD-9136 with the LSD1 inhibitors represses the induction of RUNX1 and PU.1, therefore rescues the yield of erythroid cells caused by LSD1 inhibition. Our data indicate that our novel LSD1 inhibitors can effectively induce HbF levels and reduce disease pathologies in SCD mice, and are well-tolerated by oral administration. We anticipate that these new compounds will offer new therapeutic possibilities for treating SCD.
Project description:Lysine Specific Demethylase 1 (LSD1, KDM1A) functions as a transcriptional corepressor through demethylation of histone 3 lysine 4 (H3K4), but has coactivator function on some genes through unclear mechanisms. We show that LSD1, interacting with CoREST, associates with and coactivates androgen receptor (AR) on a large fraction of androgen-stimulated genes. A subset of these AR/LSD1-associated enhancer sites have histone 3 threonine 6 phosphorylation (H3T6ph), and these sites are further enriched for androgen-stimulated genes. Significantly, despite its coactivator activity, LSD1 still mediates H3K4me2 demethylation at these androgen-stimulated enhancers. FOXA1 is also associated with LSD1 at AR regulated enhancer sites, and a FOXA1 interaction with LSD1 enhances binding of both proteins at these sites. These findings show LSD1 functions broadly as a regulator of AR function, that it maintains a transcriptional repression function at AR-regulated enhancers through H3K4 demethylation, and has a distinct AR-linked coactivator function mediated by demethylation of other substrates. Determine the role of LSD1 in androgen signaling.