Project description:Human CB HSC enriched fractions were treated with LSD1 inhibitor 2-PCPA and UM171 to identify differntially regulated genes by these compounds.
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: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.
Project description:We discovered that mice that lack Lsd1 in hematopoietic cells were exhibited increased frequencies of CD150+ CD48- lin- c-Kit+ Sca-1+ LT-HSCs, but completely lacked the lin- c-Kit+ Sca-1- myeloid progenitor compartment. To determine the genes altered by Lsd1-loss, CD150+ CD48- lin- c-Kit+ Sca-1+ LT-HSCs from Lsd1fl/fl and Lsd1fl/fl Mx1Cre mice were FACS-purified to be analyzed by gene expression profiling.
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:LSD1 (also known as KDM1A) is a histone demethylase and a key regulator of gene expression in embryonic stem cells and cancer. LSD1 was initially identified as a transcriptional repressor via its demethylation of active histone H3 marks (di-methyl lysine 4 [2MK4]). In prostate cancer, specifically, LSD1 also co-localizes with the AR and demethylates repressive 2MK9 histone marks from androgen-responsive AR target genes, facilitating androgen-mediated induction of AR-regulated gene expression and androgen-induced proliferation in androgen-dependent cancers. Recently, it was shown that treatment with high doses of androgens (e.g.10-fold higher doses than those required for induction of expression of androgen-activated genes such as PSA) recruits LSD1 and AR to an enhancer within the AR; this AR and LSD1 recruitment represses AR transcription. Thus, LSD1 appears to play a role in mediating both the proliferative and repressive phases of the biphasic androgen dose-response curve. For these reasons, we hypothesized that LSD1 might be important for maintenance of AR signalling in castration-resistant prostate cancer (CRPC) tumors. However, in this report, we describe a distinct role of LSD1 as a driver of proliferation and survival of prostate cancer cells, including CRPC cells, irrespective of androgens or even AR expression. Specifically, LSD1 activates expression of cell cycle, mitosis, and embryonic stem cell maintenance pathways that are enriched in lethal prostate cancers - pathways not activated by androgens. Finally, we observe that treatment with a new LSD1 inhibitor potently and specifically suppresses LSD1 function and suppresses CRPC growth and survival in vitro and in vivo. Our data place LSD1 as a key driver of androgen-independent survival in lethal prostate cancers and demonstrate the potential of LSD1-directed therapies in the near-term. The enclosed files are from microarrays experiments after suppressing LSD1 with RNAi or stimulating cells with the androgen agonist dihydrotestosterone (DHT).
Project description:Hepatic stellate cells (HSCs) experience phenotypic transformation, from the quiescent phenotype to the activated one, after different etiologies of liver injury. Liver fibrosis is then occurred upon the activation of HSCs. miR-16 deficiency is identified to be an important characteristic of HSCs activation. We used Affymetrix rat 230 2.0 arrays (Affymetrix, Santa Clara, U.S.A.) to uncover the global alternations of transcriptome under miR-16 restoration. We isolated quiescent hepatic stellate cells (HSCs) from adult male SD rats (normal control group) by in situ perfusion and density-gradient centrifugation. Activated HSCs were separated from rats of fibrosis model group, which were treated by 40% carbon tetrachloride (CCl4) for 8 weeks, by means of liver section, digestion and sequential centrifugation. Quiescent and activated HSCs were then divided into 4 groups at random, namely quiescent HSCs, activated HSCs, pLV-miR-16-treated HSCs and pLV-GFP-treated HSCs. The pLV-miR-16-treated group, pLV-GFP-treated group were infected with pLV-miR-16 and pLV-GFP, respectively.