title: EZH2 is a potential therapeutic target for H3K27M-mutant pediatric gliomas.
abstract: Diffuse intrinsic pontine glioma (DIPG) is an aggressive brain tumor that is located in the pons and primarily affects children. Nearly 80% of DIPGs harbor mutations in histone H3 genes, wherein lysine 27 is substituted with methionine (H3K27M). H3K27M has been shown to inhibit polycomb repressive complex 2 (PRC2), a multiprotein complex responsible for the methylation of H3 at lysine 27 (H3K27me), by binding to its catalytic subunit EZH2. Although DIPGs with the H3K27M mutation show global loss of H3K27me3, several genes retain H3K27me3. Here we describe a mouse model of DIPG in which H3K27M potentiates tumorigenesis. Using this model and primary patient-derived DIPG cell lines, we show that H3K27M-expressing tumors require PRC2 for proliferation. Furthermore, we demonstrate that small-molecule EZH2 inhibitors abolish tumor cell growth through a mechanism that is dependent on the induction of the tumor-suppressor protein p16INK4A. Genome-wide enrichment analyses show that the genes that retain H3K27me3 in H3K27M cells are strong polycomb targets. Furthermore, we find a highly significant overlap between genes that retain H3K27me3 in the DIPG mouse model and in human primary DIPGs expressing H3K27M. Taken together, these results show that residual PRC2 activity is required for the proliferation of H3K27M-expressing DIPGs, and that inhibition of EZH2 is a potential therapeutic strategy for the treatment of these tumors.
authors.affiliation: Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark.|Centre for Epigenetics, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Faizaan
authors.initials: F
authors.lastname: Mohammad
authors.affiliation: Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark.|Centre for Epigenetics, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Simon
authors.initials: S
authors.lastname: Weissmann
authors.affiliation: Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark.|Centre for Epigenetics, University of Copenhagen, Copenhagen, Denmark.|The Danish Stem Cell Center (Danstem), University of Copenhagen, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Leblanc
authors.affiliation: Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark.|Centre for Epigenetics, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Deo P
authors.initials: DP
authors.lastname: Pandey
authors.affiliation: Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark.|Centre for Epigenetics, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jonas W
authors.initials: JW
authors.lastname: Højfeldt
authors.affiliation: Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark.|Centre for Epigenetics, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Itys
authors.identifier: http://orcid.org/0000-0001-7265-2284
authors.initials: I
authors.lastname: Comet
authors.affiliation: Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark.|Centre for Epigenetics, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Chunqin
authors.initials: C
authors.lastname: Zheng
authors.affiliation: Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jens Vilstrup
authors.initials: JV
authors.lastname: Johansen
authors.affiliation: Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark.|The Danish Stem Cell Center (Danstem), University of Copenhagen, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.|The Finsen Laboratory, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.|The Bioinformatics Centre, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Nicolas
authors.identifier: http://orcid.org/0000-0001-5208-8874
authors.initials: N
authors.lastname: Rapin
authors.affiliation: Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark.|The Danish Stem Cell Center (Danstem), University of Copenhagen, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.|The Finsen Laboratory, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Bo T
authors.identifier: http://orcid.org/0000-0001-6043-0844
authors.initials: BT
authors.lastname: Porse
authors.affiliation: Centre for Epigenetics, University of Copenhagen, Copenhagen, Denmark.|Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, Odense M, Denmark.
authors.forename: Andrey
authors.initials: A
authors.lastname: Tvardovskiy
authors.affiliation: Centre for Epigenetics, University of Copenhagen, Copenhagen, Denmark.|Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, Odense M, Denmark.
authors.forename: Ole N
authors.identifier: http://orcid.org/0000-0003-1862-8528
authors.initials: ON
authors.lastname: Jensen
authors.affiliation: Department of Pediatric Hematology and Oncology, Hospital Sant Joan de Déu Barcelona, Barcelona, Spain.
authors.forename: Nagore G
authors.initials: NG
authors.lastname: Olaciregui
authors.affiliation: Department of Pediatric Hematology and Oncology, Hospital Sant Joan de Déu Barcelona, Barcelona, Spain.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Lavarino
authors.affiliation: Pathology, Hospital Sant Joan de Déu Barcelona, Barcelona, Spain.
authors.forename: Mariona
authors.initials: M
authors.lastname: Suñol
authors.affiliation: Department of Pediatric Hematology and Oncology, Hospital Sant Joan de Déu Barcelona, Barcelona, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: de Torres
authors.affiliation: Department of Pediatric Hematology and Oncology, Hospital Sant Joan de Déu Barcelona, Barcelona, Spain.
authors.forename: Jaume
authors.identifier: http://orcid.org/0000-0002-9386-5980
authors.initials: J
authors.lastname: Mora
authors.affiliation: Department of Pediatric Hematology and Oncology, Hospital Sant Joan de Déu Barcelona, Barcelona, Spain.
authors.forename: Angel M
authors.initials: AM
authors.lastname: Carcaboso
authors.affiliation: Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark.|Centre for Epigenetics, University of Copenhagen, Copenhagen, Denmark.|The Danish Stem Cell Center (Danstem), University of Copenhagen, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Kristian
authors.identifier: http://orcid.org/0000-0003-1975-6097
authors.initials: K
authors.lastname: Helin
mesh_terms: D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D001713:Biphenyl Compounds; D001932:Brain Neoplasms / Q000235:genetics; D020295:Brain Stem Neoplasms / Q000235:genetics*; D064113:CRISPR-Cas Systems; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000235:genetics*; D047369:Chromatin Immunoprecipitation; D002853:Chromatography, Liquid; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000187:drug effects / Q000235:genetics; D004195:Disease Models, Animal; D000071221:Enhancer of Zeste Homolog 2 Protein / Q000037:antagonists & inhibitors / Q000235:genetics*; D055786:Gene Knockout Techniques; D005909:Glioblastoma / Q000235:genetics; D005910:Glioma / Q000235:genetics*; D006657:Histones / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007191:Indazoles / Q000494:pharmacology; D051379:Mice; D016513:Mice, SCID; D058990:Molecular Targeted Therapy; D009025:Morpholines; D009154:Mutation; D009368:Neoplasm Transplantation; D058953:Neural Stem Cells; D063151:Polycomb Repressive Complex 2 / Q000235:genetics; D011728:Pyridones / Q000494:pharmacology; D053719:Tandem Mass Spectrometry; D025803:Tumor Suppressor Protein p14ARF / Q000187:drug effects / Q000235:genetics
chemical_list: D001549:Benzamides; D001713:Biphenyl Compounds; D019941:Cyclin-Dependent Kinase Inhibitor p16; C586265:GSK343; D006657:Histones; D007191:Indazoles; D009025:Morpholines; D011728:Pyridones; D025803:Tumor Suppressor Protein p14ARF; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; C498410:Ezh2 protein, mouse; D063151:Polycomb Repressive Complex 2; C000593333:tazemetostat