Aberrant enhancer hypomethylation contributes to hepatic carcinogenesis through global transcriptional reprogramming.
Nat Commun
; 10(1): 335, 2019 01 18.
Article
en En
| MEDLINE
| ID: mdl-30659195
ABSTRACT
Hepatocellular carcinomas (HCC) exhibit distinct promoter hypermethylation patterns, but the epigenetic regulation and function of transcriptional enhancers remain unclear. Here, our affinity- and bisulfite-based whole-genome sequencing analyses reveal global enhancer hypomethylation in human HCCs. Integrative epigenomic characterization further pinpoints a recurrent hypomethylated enhancer of CCAAT/enhancer-binding protein-beta (C/EBPß) which correlates with C/EBPß over-expression and poorer prognosis of patients. Demethylation of C/EBPß enhancer reactivates a self-reinforcing enhancer-target loop via direct transcriptional up-regulation of enhancer RNA. Conversely, deletion of this enhancer via CRISPR/Cas9 reduces C/EBPß expression and its genome-wide co-occupancy with BRD4 at H3K27ac-marked enhancers and super-enhancers, leading to drastic suppression of driver oncogenes and HCC tumorigenicity. Hepatitis B X protein transgenic mouse model of HCC recapitulates this paradigm, as C/ebpß enhancer hypomethylation associates with oncogenic activation in early tumorigenesis. These results support a causal link between aberrant enhancer hypomethylation and C/EBPß over-expression, thereby contributing to hepatocarcinogenesis through global transcriptional reprogramming.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Secuencias Reguladoras de Ácidos Nucleicos
/
Metilación de ADN
/
Carcinogénesis
/
Neoplasias Hepáticas
Tipo de estudio:
Prognostic_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Nat Commun
Asunto de la revista:
BIOLOGIA
/
CIENCIA
Año:
2019
Tipo del documento:
Article
País de afiliación:
China