Intragenic DNA methylation and BORIS-mediated cancer-specific splicing contribute to the Warburg effect

Proc Natl Acad Sci U S A. 2017 Oct 24;114(43):11440-11445. doi: 10.1073/pnas.1708447114. Epub 2017 Oct 9.

Abstract

Aberrant alternative splicing and epigenetic changes are both associated with various cancers, but epigenetic regulation of alternative splicing in cancer is largely unknown. Here we report that the intragenic DNA methylation-mediated binding of Brother of Regulator of Imprinted Sites (BORIS) at the alternative exon of Pyruvate Kinase (PKM) is associated with cancer-specific splicing that promotes the Warburg effect and breast cancer progression. Interestingly, the inhibition of DNA methylation, BORIS depletion, or CRISPR/Cas9-mediated deletion of the BORIS binding site leads to a splicing switch from cancer-specific PKM2 to normal PKM1 isoform. This results in the reversal of the Warburg effect and the inhibition of breast cancer cell growth, which may serve as a useful approach to inhibit the growth of breast cancer cells. Importantly, our results show that in addition to PKM splicing, BORIS also regulates the alternative splicing of several genes in a DNA methylation-dependent manner. Our findings highlight the role of intragenic DNA methylation and DNA binding protein BORIS in cancer-specific splicing and its role in tumorigenesis.

Keywords: BORIS; DNA methylation; Warburg effect; alternative splicing; cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / metabolism*
  • Caspases / genetics
  • Caspases / metabolism
  • Cell Line, Tumor
  • Cell Survival
  • Chromatin Immunoprecipitation
  • DNA / genetics
  • DNA Methylation*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Female
  • Gene Expression Regulation, Neoplastic
  • Glucose / metabolism
  • Humans
  • Protein Array Analysis
  • RNA Interference
  • RNA, Small Interfering
  • Transcriptome

Substances

  • CTCFL protein, human
  • DNA-Binding Proteins
  • RNA, Small Interfering
  • DNA
  • Caspases
  • Glucose