Aberrant enhancer hypomethylation contributes to hepatic carcinogenesis through global transcriptional reprogramming

  • Lei Xiong
  • , Feng Wu
  • , Qiong Wu
  • , Liangliang Xu
  • , Otto K. Cheung
  • , Wei Kang
  • , Myth T. Mok
  • , Lemuel L.M. Szeto
  • , Cheuk Yin Lun
  • , Raymond W. Lung
  • , Jinglin Zhang
  • , Ken H. Yu
  • , Sau Dan Lee
  • , Guangcun Huang
  • , Chiou Miin Wang
  • , Joseph Liu
  • , Zhuo Yu
  • , Dae Yeul Yu
  • , Jian Liang Chou
  • , Wan Hong Huang
  • Bo Feng, Yue Sun Cheung, Paul B. Lai, Patrick Tan, Nathalie Wong, Michael W. Chan, Tim H. Huang, Kevin Y. Yip, Alfred S. Cheng, Ka Fai To

Research output: Contribution to journalArticlepeer-review

77 Scopus citations

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/EBPβ) which correlates with C/EBPβ over-expression and poorer prognosis of patients. Demethylation of C/EBPβ 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/EBPβ 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/ebpβ enhancer hypomethylation associates with oncogenic activation in early tumorigenesis. These results support a causal link between aberrant enhancer hypomethylation and C/EBPβ over-expression, thereby contributing to hepatocarcinogenesis through global transcriptional reprogramming.

Original languageEnglish (US)
Article number335
JournalNature communications
Volume10
Issue number1
DOIs
StatePublished - Dec 1 2019

ASJC Scopus subject areas

  • General Chemistry
  • General Biochemistry, Genetics and Molecular Biology
  • General Physics and Astronomy

Fingerprint

Dive into the research topics of 'Aberrant enhancer hypomethylation contributes to hepatic carcinogenesis through global transcriptional reprogramming'. Together they form a unique fingerprint.

Cite this