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

T. Nakatsuka, K. Tateishi, Y. Kudo, K. Yamamoto, H. Nakagawa, H. Fujiwara, R. Takahashi, K. Miyabayashi, Y. Asaoka, Y. Tanaka, H. Ijichi, Y. Hirata, M. Otsuka, M. Kato, J. Sakai, M. Tachibana, H. Aburatani, Y. Shinkai, K. Koike

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22 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)6262-6271
Number of pages10
JournalOncogene
Volume36
Issue number45
DOIs
Publication statusPublished - 2017 Nov 9

ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Cancer Research

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