miR-137 mediates the functional link between c-Myc and EZH2 that regulates cisplatin resistance in ovarian cancer

Oncogene. 2019 Jan;38(4):564-580. doi: 10.1038/s41388-018-0459-x. Epub 2018 Aug 30.

Abstract

Platinum drugs are used in first-line to treat ovarian cancer, but most of the patients eventually generate resistance after treatment with these drugs. Although both c-Myc and EZH2 have been implicated in regulating cisplatin resistance in ovarian cancer, the interplay between these two regulators is poorly understood. Using RNA sequence analysis (RNA-seq), for the first time we find that miR-137 level is extremely low in cisplatin resistant ovarian cancer cells, correlating with higher levels of c-Myc and EZH2 expression. Further analyses indicate that in resistant cells c-Myc enhances the expression of EZH2 by directly suppressing miR-137 that targets EZH2 mRNA, and increased expression of EZH2 activates cellular survival pathways, resulting in the resistance to cisplatin. Inhibition of c-Myc-miR-137-EZH2 pathway re-sensitizes resistant cells to cisplatin. Both in vivo and in vitro analyses indicate that cisplatin treatment activates c-Myc-miR-137-EZH2 pathway. Importantly, elevated c-Myc-miR-137-EZH2 pathway in resistant cells is sustained by dual oxidase maturation factor 1 (DUOXA1)-mediated production of reactive oxygen species (ROS). Significantly, clinical studies further confirm the activated c-Myc-miR-137-EZH2 pathway in platinum drug-resistant or recurrent ovarian cancer patients. Thus, our studies elucidate a novel role of miR-137 in regulating c-Myc-EZH2 axis that is crucial to the regulation of cisplatin resistance in ovarian cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology*
  • Cell Line, Tumor
  • Cisplatin / pharmacology*
  • Drug Resistance, Neoplasm / genetics
  • Drug Resistance, Neoplasm / physiology*
  • Enhancer of Zeste Homolog 2 Protein / antagonists & inhibitors
  • Enhancer of Zeste Homolog 2 Protein / genetics
  • Enhancer of Zeste Homolog 2 Protein / physiology*
  • Female
  • Gene Expression Regulation, Neoplastic / genetics
  • Gene Expression Regulation, Neoplastic / physiology
  • Humans
  • MicroRNAs / genetics
  • MicroRNAs / physiology*
  • Neoplasm Proteins / antagonists & inhibitors
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / physiology*
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / genetics
  • Ovarian Neoplasms / metabolism
  • Promoter Regions, Genetic
  • Proto-Oncogene Proteins c-myc / physiology*
  • RNA, Neoplasm / genetics
  • RNA, Neoplasm / physiology*
  • Recombinant Fusion Proteins / metabolism
  • Sequence Analysis, RNA
  • Signal Transduction / physiology

Substances

  • Antineoplastic Agents
  • MIRN137 microRNA, human
  • MYC protein, human
  • MicroRNAs
  • Neoplasm Proteins
  • Proto-Oncogene Proteins c-myc
  • RNA, Neoplasm
  • Recombinant Fusion Proteins
  • EZH2 protein, human
  • Enhancer of Zeste Homolog 2 Protein
  • Cisplatin