MBD3 mediates epigenetic regulation on EPAS1 promoter in cancer

Tumour Biol. 2016 Oct;37(10):13455-13467. doi: 10.1007/s13277-016-5237-1. Epub 2016 Jul 27.


Hypoxia-inducible factor 2α (HIF2α) plays critical roles in cancer progression. Although the mechanisms of HIF2α translation and degradation have been well studied, the mechanism for HIF2α regulation at transcriptional level is still not fully understood. Here, we present evidence that DNA methylation in promoter contributes to transcription of EPAS1 coding HIF2α. Methylated CpG binding protein 3 (MBD3) contributes to the intricate regulatory mechanism. We showed that MBD3 bound to the EPAS1 promoter in breast cancer cells and amplified EPAS1 transcription through demethylating CpG located around transcriptional start site in MDA-MB-468 cells. This enabled MDA-MB-468 cells to activate HIF2α-mediated angiogenesis. However, in 7860 cells, the demethylation function of MBD3 on EPAS1 was not observed because of the poor methylated-CpG promoter. Nevertheless, depletion of MBD3 induced by shRNA decreased EPAS1 transcription and therefore decreased HIF2α-mediated cellular response in both MDA-MB-468 and 7860 cancer cells. These results indicated that the endogenous MBD3 was involved in regulating the transcription and therefore the transcriptional activities of HIF2α, suggesting that MBD3 may be a potential therapeutic target of tumor.

Keywords: Cancer; EPAS1; MBD3; Methylation.

MeSH terms

  • Apoptosis
  • Basic Helix-Loop-Helix Transcription Factors / genetics*
  • Blotting, Western
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Carcinoma, Renal Cell / genetics
  • Carcinoma, Renal Cell / metabolism
  • Carcinoma, Renal Cell / pathology
  • Cell Proliferation
  • Cells, Cultured
  • Chromatin Immunoprecipitation
  • CpG Islands
  • DNA Methylation
  • DNA-Binding Proteins / antagonists & inhibitors
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Epigenesis, Genetic / genetics*
  • Female
  • Human Umbilical Vein Endothelial Cells / metabolism*
  • Human Umbilical Vein Endothelial Cells / pathology
  • Humans
  • Kidney Neoplasms / genetics*
  • Kidney Neoplasms / metabolism
  • Kidney Neoplasms / pathology
  • Promoter Regions, Genetic / genetics*
  • Protein Binding
  • RNA, Messenger / genetics
  • RNA, Small Interfering / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription Initiation Site


  • Basic Helix-Loop-Helix Transcription Factors
  • DNA-Binding Proteins
  • MBD3 protein, human
  • RNA, Messenger
  • RNA, Small Interfering
  • endothelial PAS domain-containing protein 1