PRC2 functions in development and congenital disorders

Deevy, Orla; Bracken, Adrian P.

doi:10.1242/dev.181354

Cited by 91 publications

(79 citation statements)

References 140 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A canonical driver of context-dependent epigenetic plasticity is the Polycomb Repressor Complex (PRC) and its catalytic subunit Enhancer of Zeste Homologue 2 (EZH2). The PRC2/EZH2 complex not only required for different neurodevelopmental processes but also associated with disease pathogenesis including GBM [13][14][15][16][17][18][19][20] . Tumor cells can also adapt to treatment metabolically by rapidly altering core metabolic pathway activity 21,22 .…”

Section: Introductionmentioning

confidence: 99%

De-novo purine biosynthesis is a major driver of chemoresistance in glioblastoma

Shireman

Atashi

Lee

et al. 2020

Preprint

View full text Add to dashboard Cite

This year nearly 20,000 lives will be lost to Glioblastoma (GBM), a treatmentresistant primary brain cancer. In this study, we identified a molecular circuit driven by epigenetic regulation that regulates the expression of ciliary protein ALR13B. We also demonstrated that ARL13B subsequently interacts with purine biosynthetic enzyme IMPDH2. Removal of ARL13B enhanced TMZ-induced DNA damage by reducing denovo purine biosynthesis and forcing GBM cells to rely on the purine salvage pathway.Furthermore, targeting can be achieved by using an FDA-approved drug, Mycophenolate Moefitil. Our results suggest a clinical evaluation of MMF in combination with TMZ treatment in glioma patients. standard of care for newly diagnosed GBM, is associated with EZH2/PRC2 regulated ARL13B. Further, we demonstrated an interaction between ARL13B and IMPDH2, a ratelimiting enzyme of purine biosynthesis, that impacts GBM's adaptive response to TMZ by inhibiting purine salvaging. Disruption of IMPDH2 activity by using an FDA approved compound Mycophenolate Moefitil (MMF) significantly increased the therapeutic efficacy of TMZ. MMF extends the survival of patient-derived xenograft (PDX) models of mice across all GBM subtypes. Our study, therefore, provides evidence of a rapidly clinically translatable opportunity to enhance the efficacy of alkylating agents in GBM. 5 Materials and MethodsAnimal studies: Athymic nude mice (NU(NCr)-Foxn1nu; Charles River Laboratory) were maintained according to all Institutional Animal Care and Use Committee guidelines. In compliance with all applicable federal and state statutes governing animal use in biomedical research, the mice were housed before and during the study in a temperatureand humidity-controlled room following a strict 12-hour light/dark cycle. Cell culture: Patient-derived xenograft (PDX) glioblastoma specimens GBM5, GBM6, GBM43, and GBM52, were obtained from Dr. C. David James (Northwestern University) and maintained for in vitro experiments in DMEM (Thermo Fischer Scientific) supplemented with 1% fetal bovine serum (FBS; Atlanta Biologicals) and 1% Antibiotic Antimycotic Solution (Corning) according to established protocols with slight alterations 23 . For the generation of shRNA knockdown lines, lentivirus particles were made using HEK293 cells (ATCC) transfected with 2nd generation packaging/envelope plasmids (Dr. Yasuhiro Ikeda, Mayo Clinic) and shRNA clones (GeneCopoeia). U251 cells were obtained from American Type Cell Culture and maintained for in vitro experiments in DMEM supplemented with 10% FBS and 1% Antibiotic Antimycotic Solution. CRISPR knockout of U251 cells was created by direct transfection with Cas9 nuclease and sgRNA targeting ARL13B (Dharmacon). All cells were passaged by washing one time with phosphate-buffered saline solution (PBS; Gibco) and detached using 0.25% trypsin/2.21mM EDTA (Corning).Flow cytometry: Flow cytometric analysis was performed on homogenized tumor tissue after HLA-based isolation from murine brains and adherent PDX cells after trypsinization.Cells we...

show abstract

Section: Introductionmentioning

confidence: 99%

De-novo purine biosynthesis is a major driver of chemoresistance in glioblastoma

Shireman

Atashi

Lee

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…Regulation of gene expression is crucial for a myriad of biological processes, including embryonic development, tissue homeostasis, and dosage compensation 2,9,10,[16][17][18] . Gene silencing mediated by Polycomb Repressive Complexes 1 and 2 (PRC1 and PRC2) allows for temporal and tissue-specific control of gene expression during development, with aberrant regulation leading to cancer and congenital disorders 19,20 . Pluripotent stem cells, including both mouse embryonic stem cells (mESC) and human induced pluripotent stem cells (iPSC), utilize the repressive H3K27me3 mark deposited by PRC2 to suppress cell type specific expression programs, maintaining pluripotency and priming stem cells for differentiation into many lineages.…”

Section: Introductionmentioning

confidence: 99%

Polycomb-mediated Genome Architecture Enables Long-range Spreading of H3K27 methylation

Kraft

Yost

Murphy

et al. 2020

Preprint

View full text Add to dashboard Cite

SUMMARYPolycomb-group proteins play critical roles in gene silencing through the deposition of histone H3 lysine 27 trimethylation (H3K27me3) and chromatin compaction1-5. This process is essential for embryonic stem cell (ESCs) pluripotency, differentiation, and development. Polycomb repressive complex 2 (PRC2) can both read and write H3K27me3, enabling progressive spread of H3K27me3 on the linear genome6. Long-range Polycomb-associated DNA contacts have also been described, but their regulation and role in gene silencing remains unclear7-10. Here, we apply H3K27me3 HiChIP11-13, a protein-directed chromosome conformation method, and optical reconstruction of chromatin architecture14 to profile long-range Polycomb-associated DNA loops that span tens to hundreds of megabases across multiple topological associated domains in mouse ESCs and human induced pluripotent stem cells7-10. We find that H3K27me3 loop anchors are enriched for Polycomb nucleation points and coincide with key developmental genes, such as Hmx1, Wnt6 and Hoxa. Genetic deletion of H3K27me3 loop anchors revealed a coupling of Polycomb-associated genome architecture and H3K27me3 deposition evidenced by disruption of spatial contact between distant loci and altered H3K27me3 in cis, both locally and megabases away on the same chromosome. Further, we find that global alterations in PRC2 occupancy resulting from an EZH2 mutant15 selectively deficient in RNA binding is accompanied by loss of Polycomb-associated DNA looping. Together, these results suggest PRC2 acts as a “genomic wormhole”, using RNA binding to enhance long range chromosome folding and H3K27me3 spreading. Additionally, developmental gene loci have novel roles in Polycomb spreading, emerging as important architectural elements of the epigenome.

show abstract

“…Besides Ezh2, other components of the PRC2 are also involved in cell lineage commitment during Xenopus early development. Mammalian PRC2 consists of three core subunits: SUZ12, EED and EZH1 or EZH2 (41). Their homologous genes are also expressed during Xenopus early development (42,43).…”

Section: Discussionmentioning

confidence: 99%

The regulatory proteins DSCR6 and Ezh2 oppositely regulate Stat3 transcriptional activity in mesoderm patterning during Xenopus development

Loreti¹,

Shi²,

Carron³

2020

Journal of Biological Chemistry

View full text Add to dashboard Cite

Embryonic cell fate specification and axis patterning requires integration of several signaling pathways that orchestrate region-specific gene expression. The transcription factor signal transducer and activator of transcription 3 (Stat3) plays important roles during early development, but it is unclear how Stat3 is activated. Here, using Xenopus as a model, we analyzed the post-translational regulation and functional consequences of Stat3 activation in dorsoventral axis patterning. We show that Stat3 phosphorylation, lysine methylation, and transcriptional activity increase before gastrulation and induce ventral mesoderm formation. Down syndrome critical region gene 6 (DSCR6), a RIPPLY family member that induces dorsal mesoderm by releasing repressive polycomb group proteins from chromatin, bound to the Stat3 C-terminal region and antagonized its transcriptional and ventralizing activities by interfering with its lysine methylation. Enhancer of zeste 2 polycomb-repressive complex 2 subunit (Ezh2) also bound to this region; however, its methyltransferase activity was required for Stat3 methylation and activation. Loss of Ezh2 resulted in dorsalization of ventral mesoderm and formation of a secondary axis. Furthermore, interference with Ezh2 phosphorylation also prevented Stat3 lysine methylation and transcriptional activity. Thus, inhibition of either Ezh2 phosphorylation or Stat3 lysine methylation compensated for the absence of DSCR6 function. These results reveal that DSCR6 and Ezh2 critically and post-translationally regulate Stat3 transcriptional activity. Ezh2 promotes Stat3 activation in ventral mesoderm formation independently of epigenetic regulation, whereas DSCR6 specifies dorsal fate by counteracting this ventralizing activity. This antagonism helps pattern the mesoderm along the dorsoventral axis, representing a critical facet of cell identity regulation during development.

show abstract

PRC2 functions in development and congenital disorders

Cited by 91 publications

References 140 publications

De-novo purine biosynthesis is a major driver of chemoresistance in glioblastoma

De-novo purine biosynthesis is a major driver of chemoresistance in glioblastoma

Polycomb-mediated Genome Architecture Enables Long-range Spreading of H3K27 methylation

The regulatory proteins DSCR6 and Ezh2 oppositely regulate Stat3 transcriptional activity in mesoderm patterning during Xenopus development

Contact Info

Product

Resources

About