Enhancer of zeste 2 polycomb repressive complex 2 subunit promotes sorafenib resistance of hepatocellular carcinoma though insulin-like growth factor 1 receptor

Anticancer Drugs. 2019 Aug;30(7):e0746. doi: 10.1097/CAD.0000000000000746.

Abstract

Enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) is the core component of polycomb repressive complex 2 and is overexpressed in several types of solid malignancies. It has been reported that EZH2 contributes to sorafenib resistance of hepatocellular carcinoma (HCC). However, its underlying molecular mechanisms remain unknown. In this study, we demonstrated that EZH2 induced sorafenib resistance of HCC cells in vitro. Mechanistically, EZH2 was a potent regulator of insulin-like growth factor 1 receptor (IGF1R) and EZH2-modulated IGF1R expression by directly transcriptionally repressing a set of microRNAs (miRNAs) including miR-101, miR-122, miR-125b, and miR-139. These miRNAs were required for EZH2-mediated sorafenib resistance by promoting IGF1R expression. Surprisingly, IGF1R inhibitors significantly reversed EZH2-induced sorafenib resistance. Collectively, we proposed a novel model for an EZH2 - miRNAs - IGF1R regulatory axis, which might provide insights into how EZH2 contributes to sorafenib resistance in HCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology
  • Apoptosis
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism*
  • Carcinoma, Hepatocellular / drug therapy
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / pathology*
  • Cell Proliferation
  • Drug Resistance, Neoplasm*
  • Enhancer of Zeste Homolog 2 Protein / genetics
  • Enhancer of Zeste Homolog 2 Protein / metabolism*
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Liver Neoplasms / drug therapy
  • Liver Neoplasms / genetics
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / pathology
  • Mice
  • MicroRNAs / genetics*
  • Prognosis
  • Receptor, IGF Type 1 / genetics
  • Receptor, IGF Type 1 / metabolism*
  • Sorafenib / pharmacology*
  • Survival Rate
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays

Substances

  • Antineoplastic Agents
  • Biomarkers, Tumor
  • IGF1R protein, human
  • MicroRNAs
  • Sorafenib
  • EZH2 protein, human
  • Enhancer of Zeste Homolog 2 Protein
  • Receptor, IGF Type 1