SETDB1 suppresses interferon responses and NK cell-mediated immunosurveillance specifically in monocytic AML: Gene expression profiles of cSAM leukemia cells with Setdb1 depletion [RNA-seq]
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ABSTRACT: Monocytic acute myeloid leukemia (AML) responds poorly to current treatments, including venetoclax-based therapy. We conducted in vivo and in vitro CRISPR/Cas9 library screenings using a mouse monocytic AML model, and identified SETDB1 and its binding partners (ATF7IP and TRIM33) as crucial tumor promoters in vivo. The growth-inhibitory effect of Setdb1 depletion in vivo was mainly dependent on NK cell-mediated cytotoxicity. Mechanistically, SETDB1 depletion upregulated interferon-stimulated genes and NKG2D ligands through demethylation of histone H3 Lys9 at the monocyte-specific enhancer regions, thereby enhancing their immunogenicity to NK cells and intrinsic apoptosis. Importantly, these effects were not observed in non-monocytic leukemia cells. We also identified the expression of MNDA and its murine counterpart Ifi203 as biomarkers to predict the sensitivity of each AML to SETDB1 depletion. Our study highlights the critical and selective role of SETDB1 in monocytic AML and underscores its potential as a therapeutic target for current unmet needs.
Project description:Monocytic acute myeloid leukemia (AML) responds poorly to current treatments, including venetoclax-based therapy. We conducted in vivo and in vitro CRISPR/Cas9 library screenings using a mouse monocytic AML model, and identified SETDB1 and its binding partners (ATF7IP and TRIM33) as crucial tumor promoters in vivo. The growth-inhibitory effect of Setdb1 depletion in vivo was mainly dependent on NK cell-mediated cytotoxicity. Mechanistically, SETDB1 depletion upregulated interferon-stimulated genes and NKG2D ligands through demethylation of histone H3 Lys9 at the monocyte-specific enhancer regions, thereby enhancing their immunogenicity to NK cells and intrinsic apoptosis. Importantly, these effects were not observed in non-monocytic leukemia cells. We also identified the expression of MNDA and its murine counterpart Ifi203 as biomarkers to predict the sensitivity of each AML to SETDB1 depletion. Our study highlights the critical and selective role of SETDB1 in monocytic AML and underscores its potential as a therapeutic target for current unmet needs.
Project description:Monocytic acute myeloid leukemia (AML) responds poorly to current treatments, including venetoclax-based therapy. We conducted in vivo and in vitro CRISPR/Cas9 library screenings using a mouse monocytic AML model, and identified SETDB1 and its binding partners (ATF7IP and TRIM33) as crucial tumor promoters in vivo. The growth-inhibitory effect of Setdb1 depletion in vivo was mainly dependent on NK cell-mediated cytotoxicity. Mechanistically, SETDB1 depletion upregulated interferon-stimulated genes and NKG2D ligands through demethylation of histone H3 Lys9 at the monocyte-specific enhancer regions, thereby enhancing their immunogenicity to NK cells and intrinsic apoptosis. Importantly, these effects were not observed in non-monocytic leukemia cells. We also identified the expression of MNDA and its murine counterpart Ifi203 as biomarkers to predict the sensitivity of each AML to SETDB1 depletion. Our study highlights the critical and selective role of SETDB1 in monocytic AML and underscores its potential as a therapeutic target for current unmet needs.
Project description:By comparing HeLa cells lacking ATF7IP or SETDB1 generated through CRISPR/Cas9-mediated gene disruption to wild-type HeLa cells, the goal of the experiment was to determine the effect of loss of the SETDB1•ATF7IP complex on the transcriptome.
Project description:By comparing HeLa cells lacking ATF7IP or SETDB1 generated through CRISPR/Cas9-mediated gene disruption to wild-type HeLa cells, the goal of the experiment was to determine the effect of loss of the SETDB1•ATF7IP complex on the distribution of the repress
Project description:SETDB1 suppresses interferon responses and NK cell-mediated immunosurveillance specifically in monocytic AML: Gene expression profiles of cSAM leukemia cells with Setdb1 depletion [RNA-seq]
Project description:SETDB1 suppresses interferon responses and NK cell-mediated immunosurveillance specifically in monocytic AML: H3K9me3 ChIP-seq of cSAM leukemia cells with Setdb1 depletion [ChIP-seq]
Project description:Despite substantial progress that has been made in understanding how tumors escape immune surveillance, measures to counteract tumor immune evasion have been limited. Suppression of tumor antigen expression is a common adaptive mechanism that cancers use to evade detection and destruction by the immune system. Epigenetic modifications play a critical role in in various aspects of immune invasion, including the regulation of tumor antigen expression. To identify novel epigenetic regulators of tumor antigen expression, we established a transplantable syngeneic tumor model of immune escape with silenced antigen expression and used this system as a platform for a CRISPR-Cas9 suppressor screen targeting genes encoding epigenetic modifiers. We found that genetic disruption of the chromatin modifiers Atf7ip or its interacting partner Setdb1 in tumor cells restored tumor antigen expression, resulting in augmented tumor immunogenicity concomitant with elevated endogenous retroviral antigens (ERVs), mRNA intron retention. ERVs disinhibition was associated with a robust type I interferon response and increased T cell infiltration, leading to rejection of cells lacking intact Atf7ip or Setdb1. ATF7IP or SETDB1 expression inversely correlated with antigen processing and presentation pathways, interferon signaling, and T cell infiltration and cytotoxicity in human cancers. Our results provide a rationale for targeting Atf7ip or Setdb1 in cancer immunotherapy.
Project description:Epigenetic regulators play a critical role in normal and malignant hematopoiesis. We recently showed that the Histone 3 Lysine 9 (H3K9) methyltransferase SETDB1 negatively regulates the expression of the pro-leukemic genes HoxA9 and its cofactor Meis1 through deposition of promoter H3K9 trimethylation (H3K9me3) in MLL-AF9 AML cells. Here, we investigated the microbiological impact of altered SETDB1 expression in AML cells. We explored changes in transcription using RNA-seq, promoter associated histone modifications using ChIP-seq, and chromatin accessibility using ATAC-seq. Next generation sequencing of AML cells with or without overexpression of SETDB1 shows that high expression of SETDB1 induces repressive changes to the promoter epigenome and downregulation of genes linked with AML, including Dock1 and the MLL-AF9 target genes Hoxa9, Six1, and others. These data reveal novel targets of SETDB1 in AML that point to a role for SETDB1 in negatively regulating pro-leukemic target genes and suppressing AML.
Project description:SETDB1 suppresses interferon responses and NK cell-mediated immunosurveillance specifically in monocytic AML: CRISPR/Cas9 screens on cSAM leukemia cells
Project description:Von Hippel-Lindau (VHL) is a tumor suppressor that functions as the substrate recognition subunit of the CRL2VHL E3 complex. While substrates of VHL have been identified, its tumor suppressive role remains to be fully understood. For further determination of VHL substrates, we analyzed the physical interactome of VHL and identified the histone H3K9 methyltransferase SETBD1 as a novel target. SETDB1 undergoes oxygen-dependent hydroxylation by prolyl hydroxylase domain proteins (PHD) and the CRL2VHL complex recognizes hydroxylated SETDB1 for ubiquitin-mediated degradation. Under hypoxic conditions, SETDB1 accumulates by escaping CRL2VHL activity. Loss of SETDB1 in hypoxia compared with that in normoxia escalates the production of transposable element (TE)-derived double-stranded RNAs (dsRNAs), thereby hyperactivating the immune-inflammatory response. In addition, strong derepression of TEs in hypoxic cells lacking SETDB1 triggers DNA damage-induced death. Our collective results support a molecular mechanism of oxygen-dependent SETDB1 degradation by the CRL2VHL E3 complex and reveal a role of SETDB1 in genome stability under hypoxia.