Endocrine resistance and breast cancer plasticity are controlled by CoREST
Ontology highlight
ABSTRACT: Using a new model system to track evolution of resistance from ER+ to ER-, we show that the LSD1/CoREST complex is a key determinant for luminal-to-basal reprogramming independently on LSD1’s enzymatic activity.
Project description:Resistance to cancer treatment remains a major clinical hurdle. Here, we demonstrate that the CoREST complex is a key determinant of endocrine resistance and ER+ breast cancer plasticity. In endocrine-sensitive cells, CoREST is recruited to regulatory regions co-bound to ERα and FOXA1 to regulate the estrogen pathway. In contrast, during temporal reprogramming towards a resistant state, CoREST is recruited to AP-1 sites. In reprogrammed cells, CoREST favors chromatin opening, cJUN binding to chromatin, and gene activation by controlling SWI/SNF recruitment independently of the demethylase activity of the CoREST subunit LSD1. Genetic and pharmacological CoREST inhibition reduces tumorigenesis and metastasis of endocrine-sensitive and endocrine-resistant xenograft models. Consistently, CoREST controls a gene signature involved in invasiveness in clinical breast tumors resistant to endocrine therapies. Our studies reveal CoREST functions that are co-opted to drive cellular plasticity and resistance to endocrine therapies and tumorigenesis, thus establishing CoREST as a potential therapeutic target for the treatment of advanced breast cancer.
Project description:Lysine specific demethylase 1 (LSD1/KDM1A) regulates gene expression as part of the CoREST complex, along with co-repressor of REST (CoREST) and histone deacetylase 1 (HDAC1). CoREST is recruited to specific genomic loci by components of the core complex and numerous transient interactions with chromatin associated factors and transcription factors. To sample the chromatin environment in proximity to CoREST, we performed proximity-dependent biotin-identification (BioID) with four different members of the complex in 293T cells. Retaining only targets identified with 3 out of 4 baits, we identified 302 CoREST-associated proteins. Among this group were 16 of 18 known CoREST components and numerous novel associations, including readers (CHD3, 4, 6, 7 and 8), writers (KMT2B and KMT2D) and erasers (KDM2B) of histone methylation. However, components of other HDAC1 containing complexes (e.g. Sin3A, NuRD) were largely absent, suggesting that CoREST functions independently. As LSD1 plays an essential role in early embryonic development, we performed BioID using the endogeneously tagged protein in pluripotent, early- and late-differentiating embryonic stem cells. We identified 157 LSD1-associated proteins of which 66 were constitutively associated across all three time-points (44%), including novel interactions with the MMB and ChAHP complexes. These data imply that the majority of CoREST interactions are dynamic and highly cell type dependent.
Project description:In this study, we report that ZNF516 functions as a transcription repressor. We showed that ZNF516 is physically associated with the CtBP/LSD1/CoREST corepressor complex and transcriptionally represses the expression of a collection of genes including EGFR that are critically involved in cell proliferation and motility. We demonstrated that the ZNF516 inhibits the proliferation and invasive potential of breast cancer cells in vitro and suppresses breast cancer growth and metastasis in vivo. We explored the clinical significance of the ZNF516-CtBP/LSD1/CoREST-EGFR axis in breast carcinomas.
Project description:Using the sea anemone Nematostella vectensis as a model for early branching metazoans, we show that CoREST is an animal-specific protein that assembles a conserved histone-modifying complex including Lsd1 and HDAC1/2. We further show that the Nematostella complex is similar in composition to vertebrates.
Project description:Epstein-Barr virus (EBV) contributes to ~1.5% of human cancers, including lymphomas, gastric and nasopharyngeal carcinomas. In most of these, nearly 80 viral lytic genes are silenced by incompletely understood epigenetic mechanisms, precluding use of antiviral agents such as ganciclovir to treat the 200,000 EBV-associated cancers/year. To identify host factors critical for EBV latency, we performed a human genome-wide CRISPR-Cas9 screen in Burkitt B-cells. Top hits included the lysine-specific histone demethylase LSD1 and its co-repressors ZNF217 and CoREST. LSD1 removes histone 3 lysine 4 (H3K4) and histone 3 lysine 9 (H3K9) methylation marks to downmodulate chromatin activation. LSD1, ZNF217 or CoREST knockout triggered EBV reactivation, as did a LSD1 small molecule antagonist, whose effects were additive with histone deacetylase inhibition. LSD1 blockade reactivated EBV in Burkitt lymphoma, gastric carcinoma and nasopharyngeal carcinoma models, sensitized cells to ganciclovir cytotoxicity and induced EBV reactivation in murine xenografts. ZNF217 and LSD1 co-occupied the EBV immediate early gene BZLF1 promoter, which drives B-cell lytic cycle, as well as to the oriLyt enhancer regions recently implicated in EBV reactivation. LSD1 depletion increased levels of activating histone 3 lysine 4 (H3K4) methylation but not repressive histone lysine 9 methylation marks at BZLF1 and oriLyt and induced their interaction by long-range DNA looping. An orthogonal CRISPR screen highlighted a key H3K4 methyltransferase KMT2D role in driving EBV reactivation. Our results highlight H3K4 methylation as a major EBV lytic switch regulator and suggest novel therapeutic approaches.
Project description:SFMBT1 is a poorly characterized mammalian MBT domain-containing protein homologous to Drosophila SFMBT, a Polycomb group protein involved in epigenetic regulation of gene expression. Here, we show that SFMBT1 regulates transcription in somatic cells and during spermatogenesis through the formation of a stable complex with LSD1 and CoREST. When bound to its gene targets, SFMBT1 recruits its associated proteins and causes chromatin compaction and transcriptional repression. SFMBT1, LSD1, and CoREST share a large fraction of target genes including those encoding replication-dependent histones. Simultaneous occupancy of histone genes by SFMBT1, LSD1, and CoREST is regulated during the cell cycle and correlates with the loss of RNA polymerase II at these promoters during G2, M, and G1. The interplay between the repressive SFMBT1M-bM-^@M-^SLSD1M-bM-^@M-^SCoREST complex and RNA polymerase II contributes to the timely transcriptional regulation of histone genes in human cells. SFMBT1, LSD1, and CoREST also form a stable complex in germ cells and their chromatin binding activity is regulated during spermatogenesis. RNA-seq in HeLaS3 cells ctrl compared to triple knockdown for SFMBT1, CoREST, and LSD1
Project description:Lysine specific demethylase 1 (LSD1), which demethylates mono- and di- methylated histone H3-Lys4 as part of a complex including CoREST and histone deacetylases (HDAC), is essential for embryonic development in the mouse beyond e6.5 days. Here, we demonstrate that LSD1 expression and therefore function, is restricted to the epiblast of the post- implantation embryo. Conditional deletion of LSD1 in mouse embryonic stem (ES) cells, in vitro counterpart of the epiblast, revealed a reduction in CoREST protein, a subsequent decrease in associated HDAC activity and a global increase in Histone H3 Lys56 acetylation. Despite this biochemical perturbation, LSD1 deleted ES cells proliferate normally and retain stem cell characteristics. Loss of LSD1 causes the aberrant expression of 588 genes, including a number of transcription factors with roles in tissue development such as brachyury, Hoxb7, Hoxd8 and RARγ. Brachyury, a key-regulator of mesodermal differentiation, is a direct target gene of LSD1 and is over-expressed in e6.5 day Lsd1 genetrap embryos. Thus, LSD1 is required for the appropriate expression of key developmental regulators, via the stabilization of the LSD1/CoREST/HDAC complex, during early embryonic development. RNA samples from Lsd1Lox/Δ3 and Lsd1Δ3/Δ3 cells were compared, three biological replicates were performed.
Project description:Genomic amplification of OTUD7B is frequently found across human cancers. But its role in tumorigenesis is poorly understood. Lysine‐specific demethylase 1 (LSD1) is known to execute epigenetic regulation by forming corepressor complex with CoREST/histone deacetylases (HDACs). However, the molecular mechanisms by which cells maintain LSD1/CoREST complex integrity are unknown. Here, it is reported that LSD1 protein undergoes K63‐linked polyubiquitination. OTUD7B is responsible for LSD1 deubiquitination at K226/277 residues, resulting in dynamic control of LSD1 binding partner specificity and cellular homeostasis. OTUD7B deficiency increases K63‐linked ubiquitination of LSD1, which disrupts LSD1/CoREST complex formation and targets LSD1 for p62‐mediated proteolysis. Consequently, OTUD7B deficiency impairs genome‐wide LSD1 occupancy and enhances the methylation of H3K4/H3K9, therefore profoundly impacting global gene expression and abrogating breast cancer metastasis. Moreover, physiological fluctuation of OTUD7B modulates cell cycle‐dependent LSD1 oscillation, ensuring the G1/S transition. Both OTUD7B and LSD1 proteins are overpresented in high‐grade or metastatic human breast cancer, while dysregulation of either protein is associated with poor survival and metastasis. Thus, OTUD7B plays a unique partner‐switching role in maintaining the integrity of LSD1/CoREST corepressor complex, LSD1 turnover, and breast cancer metastasis.