Gene expression profile of human multiple myeloma cell line MM.1S after knockdown of KDM6B
Ontology highlight
ABSTRACT: Recent studies have delineated cancer type-specific roles of histone 3 lysine 27 (H3K27) demethylase KDM6B/JMJD3 depending on its H3K27 demethylase activity. Here we show that KDM6B is expressed in multiple myeloma (MM); and that shRNA-mediated knockdown and CRISPR-mediated knockout of KDM6B abrogate MM cell growth and survival. TNFα or bone marrow stromal cell culture supernatants induce KDM6B, which is blocked by IKKβ inhibitor MLN120B, suggesting KDM6B is regulated by NF-κB signaling in MM cells. RNA-sequencing and subsequent ChIP-qPCR analyses reveal that KDM6B is recruited to the loci of genes encoding components of MAPK signaling pathway including ELK1 and FOS, and upregulates these genes expression without affecting H3K27 methylation level. Overexpression of catalytically-inactive KDM6B activates expression of MAPK pathway-related genes, confirming its function independent of demethylase activity. We further demonstrate that downstream targets of KDM6B, ELK1 and FOS, confer MM cell growth. Our study therefore delineates KDM6B function that links NF-κB and MAPK signaling pathway mediating MM cell growth and survival, and validates KDM6B as a novel therapeutic target in MM.
Project description:Recent studies have indicated that the histone 3 lysine 27 (H3K27me2/3) demethylase KDM6B (JMJD3) is frequently upregulated in a myriad of blood disorders including myelodysplastic syndrome (MDS), T-cell acute lymphoblastic leukemia (T-ALL), and multiple myeloma (MM) suggesting it may have important functions in the pathogenesis of hematopoietic cancers. Here, we sought to determine the role of Kdm6b in hematopoietic stem cell (HSC) fate decisions under normal and malignant conditions to evaluate its potential as a therapeutic target. We show that loss of Kdm6b leads to a significant reduction in phenotypic and functional HSCs in adult mice, and that Kdm6b is necessary for HSC self-renewal in response to inflammatory, genotoxic and oncogenic stress. Additionally, we show that loss of Kdm6b in HSCs leads to a stress-response gene expression signature in native HSCs that is independent of its demethylase activity. Loss of Kdm6b lead to increased expression of a subset of genes implicated in HSC quiescence (e.g. Fos, Jun, Ier2, Dusp1, Zfp36). Upon inflammatory or replicative stress, HSCs deficient for Kdm6b are not able to efficiently resolve this gene expression program, leading to increased quiescence and a self-renewal block, forcing them to differentiate. These findings show that Kdm6b is necessary for self-renewal of normal and leukemic stem cells, and suggest inhibiting Kdm6b in blood cancers in the presence of proliferative agents may force differentiation and eventual depletion of leukemic stem cells.
Project description:Multiple myeloma (MM) progression is linked to chronic NF-κB activation in myeloma cells. However, the identity and source of autocrine/paracrine signals driving NF-κB activation and the role of the 3D microenvironment have been scarcely investigated both in vivo and in vitro. To investigate them, we knocked-in the Venus (YFP) ORF in the NF-κB p65 gene in both MM and stromal cells. Surprisingly, a large fraction of p65-YFP MM cells engrafted in mouse bone marrow showed overall low levels of NF-κB activation whereas a small fraction was highly activated. To understand these in vivo data, we investigated NF-κB dynamics in MM and stromal cells, both alone and in co-culture. In vitro experiments exploiting microfluidics, bioreactor and microchip cell cultures highlighted crosstalk between the myeloma and stromal components that leads to mild basal activation. In contrast, we found that high-density cultures within 3D scaffolds dampen NF-κB activation in MM and stromal cells, both in basal and inflammatory conditions. It has been recently hypothesized that IL1β, and the inflammatory ME, shape the overall activity of ME components and promote the transition of Mesenchimal Stromal Cells (MSCs) toward an inflammatory NF-κB driven transcriptional phenotype (iMSCs). We tested this hypothesis in our system and found that IL1β strongly activates NF-κB in stromal but not in myeloma cells. In addition, secreted molecules from IL1β-stimulated MSCs strongly activate NF-κB only in a small fraction of MM cells. We propose that the balance between activating stimuli from iMSCs and dampening feedbacks from the 3D ME, maintains a mild NF-κB activation in myeloma cells in the patients’ BM to avoid exceedingly harmful responses.
Project description:Multiple myeloma (MM) remains incurable due to drug resistance. Ribosomal protein S3 (RPS3) has been identified as a non-Rel subunit of NF-κB. However, the detailed biological roles of RPS3 remain unclear. Here, we report for the first time that RPS3 is necessary for MM survival and drug resistance. RPS3 was highly expressed in MM, and knockout of RPS3 in MM inhibited cell growth and induced cell apoptosis both in vitro and in vivo. Overexpression of RPS3 mediated the proteasome inhibitor resistance of MM and delayed the survival of MM tumour-bearing animals. Moreover, our present study found an interaction between RPS3 and the thyroid hormone receptor interactor 13 (TRIP13), an oncogene related to MM tumorigenesis and drug resistance. We demonstrated that the phosphorylation of RPS3 was mediated by TRIP13 via PKCδ, which played an important role in activating the canonical NF-κB signalling and inducing cell survival and drug resistance in MM. Notably, the inhibition of NF-κB signalling by the small-molecule inhibitor targeting TRIP13, DCZ0415, was capable of triggering synergistic cytotoxicity when combined with bortezomib in drug-resistant MM. This study identifies RPS3 as a novel biomarker and therapeutic target in MM.
Project description:Autophagy is essential for cellular survival and energy homeostasis under nutrient deprivation. Despite the emerging importance of nuclear events in autophagy regulation, epigenetic control of autophagy gene transcription remains unclear. Here, we identify Jumonji-D3 (JMJD3/KDM6B) histone demethylase as a key epigenetic activator of hepatic autophagy. Upon fasting-induced fibroblast growth factor-21 (FGF21) signaling, JMJD3 epigenetically upregulated global autophagy-network genes, including Tfeb, Atg7, Atgl, and Fgf21, through demethylation of histone H3K27-me3, resulting in autophagy-mediated lipid degradation. Mechanistically, phosphorylation of JMJD3 at Thr-1044 by FGF21 signal-activated PKA increased its nuclear localization and interaction with the nuclear receptor PPARto transcriptionally activate autophagy. Chronic administration of FGF21 in obese mice improved defective autophagy and hepatosteatosis in a JMJD3-dependent manner. Remarkably, in non-alcoholic fatty liver disease patients, hepatic expression of JMJD3, ATG7, LC3, and KL were substantially decreased. These findings demonstrate that FGF21-JMJD3 signaling epigenetically links nutrient deprivation with hepatic autophagy and lipid degradation in mammals
Project description:The KDM6 histone demethylases (UTX/KDM6A and JMJD3/KDM6B) mediate removal of repressive histone H3K27me3 marks to establish transcriptionally permissive chromatin. Loss of UTX in female mice is embryonic lethal. Unexpectedly, male UTX-null mice escape embryonic lethality due to expression of UTY, a paralog lacking H3K27-demethylase activity. This suggests that UTX plays an enzyme-independent role in development, and challenges the need for active H3K27-demethylation in vivo. However, the requirement for active H3K27-demethylation in stem cell-mediated tissue regeneration remains untested. Using an inducible mouse knockout that ablates UTX in satellite cells, we show that active H3K27-demethylation is necessary for muscle regeneration. Indeed, loss of UTX in satellite cells blocks myofiber regeneration in both male and female mice. Furthermore, we demonstrate that UTX mediates muscle regeneration through its H3K27-demethylase activity using a chemical inhibitor, and a demethylase-dead UTX knock-in mouse. Mechanistically, dissection of the muscle regenerative process revealed that UTX is required for expression of the transcription factor Myogenin that drives differentiation of muscle progenitors. Thus, we have identified a critical role for the enzymatic activity of UTX in activating muscle-specific gene expression during myofiber regeneration, revealing for the first time that active H3K27-demethylation has a physiological role in vivo. Satellite cells were sorted based on Cre-dependent expression of TdT reporter gene. Sorted UTXmKO or UTX WT satellite cells were then induced to differentiate for 24 hrs. RNA was then isolated and subjected to RNA-Seq analysis.
Project description:Herein we identified Niemann–Pick C1-like 1 (NPC1L1) as a downstream effector of PKM2. Knockout of PKM2 enhanced NPC1L1 expression in breast cancer cells, while reducing the peroxisome proliferator-activated receptor α (PPARα) signaling pathway. Fenofibrate, a PPARα agonist, promoted NPC1L1 expression. Combined administration of fenofibrate and ezetimibe, a NPC1L1 inhibitor, significantly induced cytoplasmic vacuolation and cell apoptosis. Mechanistically, combined administration activated the inositol required enzyme 1α(IRE1α)- x box binding protein spliced (XBP1s) and lysine demethylase 6B (KDM6B). XBP1s interacted with KDM6B to activate genes involved in unfold protein response through demethylating di- and tri-methylated lysine 27 of histone H3 (H3K27) and consequentially increasing the level of H3K27 acetylation in breast cancer cell lines. Fenofibrate and ezetimibe synergistically inhibited tumor growth and lung metastasis in vivo. Together, our findings reveal that dual targeting PPARα and NPC1L1 may be developed as a new regimen for breast cancer therapy.
Project description:As multiple myeloma (MM) poses a formidable therapeutic challenge despite recent progress, exploring novel targets is crucial. Mucosa-associated lymphoid tissue lymphoma translocation protein-1 (MALT1) emerges as a promising paracaspase with druggable potential, especially unexplored in MM. Our study provided compelling evidence demonstrating a statistically significant elevation of MALT1 expression in human primary MM cells. Moreover, elevated MALT1 expression was associated with a poorer prognosis in MM. Genetic deletion of MALT1 reduced cell growth, colony formation, and tumor growth in vivo. Pharmacological inhibition with 1 μM Mi-2 effectively inhibited cell growth, inducing mitochondria-dependent apoptotic cell death. Mechanistically, MALT1 inhibition disrupted diverse signal transduction pathways, notably impeding nuclear factor κB (NF-κB). Significantly, the inhibition of MALT1 demonstrated a substantial suppression of NF-κB activation by elevating IκB, disrupting the nuclear localization of p65 and C-Rel. This effect was observed in both the basal state and when stimulated by BCMA, highlighting the pivotal role of MALT1 inhibition in influencing MM cell survival. It was noteworthy that Mi-2 induces properties associated with immunogenic cell death (ICD), as evidenced by increased calreticulin (CRT), ATP release, and high-mobility group protein B1 (HMGB1) upregulation, consequently triggering ICD-associated immune activation and enhancing CD8+ T-cell cytotoxicity in vitro. In conclusion, our research highlights MALT1 as a promising druggable target for therapeutic interventions in MM, providing insights into its molecular mechanisms in MM progression.
Project description:The discovery of the first histone demethylase in 2004 (LSD1/KDM1) opened new avenues for the understanding of how histone methylation impacts cellular functions. A great number of histone demethylases have been identified since, which are potentially linked to gene regulation as well as to stem cell self-renewal and differentiation. KDM6A/UTY and KDM6B/JMJD3 are both H3K27me3/2-specific histone demethylases, which are known to play a central role in regulation of posterior development, by regulating HOX gene expression. So far nothing is known about the role of histone lysine demethylases (KDMs) during early hematopoiesis. We are studying the role of KDM6A and KDM6B on self-renewal, global gene expression and on local and global chromatin states in embryonic stem cells (ESCs) and during differentiation. In order to completely abrogate KDM6 demethylase activity in ESCs we employed a specific inhibitor (GSK-J4, Kruidenier et al. 2012). Treatment of ESCs with GSK-J4 had no effect on viability and proliferation . However, ESC differentiation in the presence of GSK-J4 was completely abrogated. In conclusion we show that ESC differentiation is completely blockend in the absence of any H3K27 demethylase activity. We used microarrays to detail the global gene expression program of genes which are differentially expressed during the early differentiation of ESC derived embryoid bodies (EBs) in the presence of GSK-J4 (KDM6 Inhibitor). ESCs (R1) have been cultured and differentiated in the presence of GSK-J4 a KDM6 specific inhibitor.
Project description:Global gene expression profiles were analyzed in HL-60 cells with SATB1 knockdown to investigate the mechanisms underlying the regulation of AML cell growth by SATB1.Genes that displayed two-fold up-regulation or 0.5-fold down-regulation in expression in comparisons were selected for further analyses. Arrays with poor quality according to the manufacturer's recommendations were excluded from further analysis.We found the differentially expressed genes were involved in NF-κB, MAPK and PI3K/Akt signaling pathways. Nuclear NF-κB p65 levels were significantly increased in SATB1 depleted HL-60 cells.
Project description:Background& Aims: The incidence of nonhepatitis B and nonhepatitis C viral (NBNC)- HCC has been rising in recent years due to the increase in NAFLD and NASH worldwide with fibrosis. However, the molecular mechanisms underlying the progression of these HCC are not fully understood. Here we observed that KDM6B, an H3K27 demethylase, was commonly downregulated in human NBNC-HCC and mouse NASH-related HCC by microarray analysis. The study aims to elucidate the molecular mechanism of KDM6B downregulation in NBNC-HCC including NASH-related HCC. Approach & Results: By immunohistochemistry, KDM6B expression was decreased in 28.7% of human HCC tissues, most of which were NBNC-HCC type. The low KDM6B expression group was accompanied by NASH in the adjacent liver. The KDM6B knockout (KO) HCC cells altered pathways of lipid metabolism by microarray and GSEA analysis. The KDM6B-KO cells significantly decreased lipid accumulation and cell reduction rates. Expression of two lipid-metabolism-related genes, G0S2 and ACSL1, were suppressed in the KDM6B-KO cells and the histone H3K27 trimethylation levels at the promoter regions were decreased when compared to the wild-type cells. Knockdown of G0S2 but not ACSL1 expression showed resistance to lipotoxicity in HCC cells. Moreover, inhibition of ATGL, a downstream target of G0S2, caused a decrease in lipid accumulation and cell proliferation. Conclusions: KDM6B regulates G0S2 expression via histone demethylation of its promoter region. Decreased KDM6B-dependent G0S2 expression through the histone modification pathway causes resistance to lipotoxicity, which may be involved in the carcinogenic mechanism of NASH-related HCC among NBNC-HCC.