Abstract
While comprehensive molecular profiling of histone H3.3 mutant pediatric high-grade glioma has revealed extensive dysregulation of the chromatin landscape, the exact mechanisms driving tumor formation remain poorly understood. Since H3.3 mutant gliomas also exhibit high levels of copy number alterations, we set out to address if the H3.3K27M oncohistone leads to destabilization of the genome. Hereto, we established a cell culture model allowing inducible H3.3K27M expression and observed an increase in mitotic abnormalities. We also found enhanced interaction of DNA replication factors with H3.3K27M during mitosis, indicating replication defects. Further functional analyses revealed increased genomic instability upon replication stress, as represented by mitotic bulky and ultrafine DNA bridges. This co-occurred with suboptimal 53BP1 nuclear body formation after mitosis in vitro, and in human glioma. Finally, we observed a decrease in ultrafine DNA bridges following deletion of the K27M mutant H3F3A allele in primary high-grade glioma cells. Together, our data uncover a role for H3.3 in DNA replication under stress conditions that is altered by the K27M mutation, promoting genomic instability and potentially glioma development.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Brain Neoplasms / genetics*
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Brain Neoplasms / pathology
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Child
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DNA Replication / genetics*
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Gene Expression Regulation, Neoplastic
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Genomic Instability*
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Glioma / genetics*
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Glioma / pathology
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Histones / physiology*
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Humans
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Mitosis / genetics
Grants and funding
This study was supported by an NWO-grant to the UMCG Microscopy and Imaging Center (UMIC, grant number 175-010-2009-023); a De Cock-Hadders foundation grant to I.B.; the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brasil, CAPES, Finance Code 001 (E.S.C.M.) (E.S.C.M. has received salary from this funding agency in the past); an Indonesia Endowment Fund for Education (LPDP) doctoral grant (PRJ-2572/LPDP/2015) to I.A (I.A. has received salary from this funding agency in the past); the Fördergemeinschaft Kinderkrebszentrum Hamburg (U.S.); a grant from the Netherlands Organization for Scientific Research (NWO-VIDI # 917.13334) to M.A.T.M.v.V; a grant from the European Research Council (ERC-Consolidator grant “TENSION”) to M.A.T.M.v.V; a KWF project grant (2018-RUG-11457) to F.F; a Stichting Kinderoncologie Groningen/SKOG project grant (16-003) to S.W.M.B; a Rosalind Franklin fellowship from the University of Groningen to S.W.M.B.; and a Dutch Cancer Society/KWF career award (RUG 2014-6903) to S.W.M.B (S.W.M.B. has received salary in the past from the Rosalind Frank fellowship and the Dutch Cancer Society/KWF career award). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.