Impact of histone demethylase KDM3A-dependent AP-1 transactivity on hepatotumorigenesis induced by PI3K activation

Oncogene. 2017 Nov 9;36(45):6262-6271. doi: 10.1038/onc.2017.222. Epub 2017 Jul 10.


Epigenetic gene regulation linked to oncogenic pathways is an important focus of cancer research. KDM3A, a histone H3 lysine 9 (H3K9) demethylase, is known to have a pro-tumorigenic function. Here, we showed that KDM3A contributes to liver tumor formation through the phosphatidylinositol 3-kinase (PI3K) pathway, which is often activated in hepatocellular carcinoma. Loss of Kdm3a attenuated tumor formation in Pik3ca transgenic (Tg) mouse livers. Transcriptome analysis of pre-cancerous liver tissues revealed that the expression of activator protein 1 (AP-1) target genes was induced by PI3K activation, but blunted upon Kdm3a ablation. Particularly, the expression of Cd44, a liver cancer stem marker, was regulated by AP-1 in a Kdm3a-dependent manner. We identified Cd44-positive hepatocytes with epithelial-mesenchymal transition-related expression profiles in the Pik3ca Tg liver and confirmed their in vivo tumorigenic capacity. Notably, the number and tumor-initiating capacity of Cd44-positive hepatocytes were governed by Kdm3a. As a mechanism in Kdm3a-dependent AP-1 transcription, Kdm3a recruited c-Jun to the AP-1 binding sites of Cd44, Mmp7 and Pdgfrb without affecting c-Jun expression. Moreover, Brg1, a component of the SWI/SNF chromatin remodeling complex, interacted with c-Jun in a Kdm3a-dependent manner and was bound to the AP-1 binding site of these genes. Finally, KDM3A and c-JUN were co-expressed in 33% of human premalignant lesions with PI3K activation. Our data suggest a critical role for KDM3A in the PI3K/AP-1 oncogenic axis and propose a novel strategy for inhibition of KDM3A against liver tumor development under PI3K pathway activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinogenesis
  • Carcinoma, Hepatocellular / enzymology
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / pathology
  • Cell Line, Tumor
  • Class I Phosphatidylinositol 3-Kinases / metabolism*
  • Epigenesis, Genetic
  • Humans
  • Jumonji Domain-Containing Histone Demethylases / metabolism*
  • Liver Neoplasms / enzymology
  • Liver Neoplasms / metabolism*
  • Liver Neoplasms / pathology
  • Liver Neoplasms, Experimental / enzymology
  • Liver Neoplasms, Experimental / metabolism
  • Liver Neoplasms, Experimental / pathology
  • Male
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphorylation
  • Signal Transduction
  • Transcription Factor AP-1 / metabolism*


  • Transcription Factor AP-1
  • Jumonji Domain-Containing Histone Demethylases
  • KDM3A protein, human
  • Kdm3a protein, mouse
  • Phosphatidylinositol 3-Kinases
  • Class I Phosphatidylinositol 3-Kinases
  • PIK3CA protein, human
  • Pik3ca protein, mouse