EZH2 has a non-catalytic and PRC2-independent role in stabilizing DDB2 to promote nucleotide excision repair.
Oncogene
; 39(25): 4798-4813, 2020 06.
Article
em En
| MEDLINE
| ID: mdl-32457468
ABSTRACT
Small cell lung cancer (SCLC) is a highly aggressive malignancy with poor outcomes associated with resistance to cisplatin-based chemotherapy. Enhancer of zeste homolog 2 (EZH2) is the catalytic subunit of polycomb repressive complex 2 (PRC2), which silences transcription through trimethylation of histone H3 lysine 27 (H3K27me3) and has emerged as an important therapeutic target with inhibitors targeting its methyltransferase activity under clinical investigation. Here, we show that EZH2 has a non-catalytic and PRC2-independent role in stabilizing DDB2 to promote nucleotide excision repair (NER) and govern cisplatin resistance in SCLC. Using a synthetic lethality screen, we identified important regulators of cisplatin resistance in SCLC cells, including EZH2. EZH2 depletion causes cellular cisplatin and UV hypersensitivity in an epistatic manner with DDB1-DDB2. EZH2 complexes with DDB1-DDB2 and promotes DDB2 stability by impairing its ubiquitination independent of methyltransferase activity or PRC2, thereby facilitating DDB2 localization to cyclobutane pyrimidine dimer crosslinks to govern their repair. Furthermore, targeting EZH2 for depletion with DZNep strongly sensitizes SCLC cells and tumors to cisplatin. Our findings reveal a non-catalytic and PRC2-independent function for EZH2 in promoting NER through DDB2 stabilization, suggesting a rationale for targeting EZH2 beyond its catalytic activity for overcoming cisplatin resistance in SCLC.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Ligação a DNA
/
Reparo do DNA
/
Complexo Repressor Polycomb 2
/
Proteína Potenciadora do Homólogo 2 de Zeste
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Oncogene
Assunto da revista:
BIOLOGIA MOLECULAR
/
NEOPLASIAS
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos