New insights into the role of oxidized histone H3 in heterochromatin

Oxidation of histone H3 (H3K4ox) by lysyl oxidase-like 2 (LOXL2) is important in triple-negative breast cancer (TNBC) cells to generate compacted heterochromatin regions. However, the molecular mechanisms by which it establishes chromatin compaction have not yet been characterized. In this thesis, w...

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Detalles Bibliográficos
Autor: Serra Bardenys, Gemma
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/668207
Acceso en línea:http://hdl.handle.net/10803/668207
Access Level:acceso abierto
Palabra clave:Heterochromatin
Breast cancer
H4K4ox
LOXL2
H2A.Z
Heterocromatina
Càncer de pit
577
Descripción
Sumario:Oxidation of histone H3 (H3K4ox) by lysyl oxidase-like 2 (LOXL2) is important in triple-negative breast cancer (TNBC) cells to generate compacted heterochromatin regions. However, the molecular mechanisms by which it establishes chromatin compaction have not yet been characterized. In this thesis, we found that LOXL2 interacts with RUVBL1, RUVBL2, BAF53A, and DMAP1, which are proteins that form complexes involved in the exchange of the histone variant H2A.Z. Genome-wide experiments showed that H2A.Z, RUVBL2, and H3K4ox colocalize in heterochromatin regions in TNBC cells. Moreover, we demonstrated that oxidation of histone H3 is linked to DDB1 recruitment to chromatin and the ubiquitination of H2A through RBX1. Interestingly, the interplay between these series of events is required to maintain H3K4ox-enriched heterochromatin regions. Loss of H3K4ox decreases the levels of H3K9me3 and alters chromatin compaction, thereby compromising the oncogenic properties of TNBC cells. Our data revealed a direct link between H3K4ox maintenance, chromatin compaction, and tumorigenic capacities and suggest novel potential targets for cancer therapy.