Inhibition of NR4A1 Promotes ROS Accumulation and IL24-Dependent Growth Arrest in Rhabdomyosarcoma

Mol Cancer Res. 2019 Nov;17(11):2221-2232. doi: 10.1158/1541-7786.MCR-19-0408. Epub 2019 Aug 28.


Nuclear receptor 4A1 (NR4A1, Nur77) is overexpressed in rhabdomyosarcoma (RMS), and inactivation of NR4A1 (siNR4A1) or treatment with the NR4A1 antagonist 1,1-bis(3'-indoly)-1-(p-hydroxy-phenyl)methane (DIM-C-pPhOH) has antiproliferative and proapoptotic effects on RMS cells. However, the mechanism by which NR4A1 inhibition exerts these effects is poorly defined. Here, we report that NR4A1 silencing or inhibition resulted in accumulation of reactive oxygen species (ROS) and ROS-dependent induction of the tumor suppressor-like cytokine IL24 in RMS cells. Mechanistically, NR4A1 was found to regulate the expression of the proreductant genes thioredoxin domain-containing 5 (TXNDC5) and isocitrate dehydrogenase 1 (IDH1), which are downregulated in RMS cells following NR4A1 knockdown or inhibition. Silencing TXNDC5 and IDH1 also induced ROS accumulation and IL24 expression in RMS cells, suggesting that NR4A1 antagonists mediate their antiproliferative and apoptotic effects through modulation of proreductant gene expression. Finally, cotreatment with the antioxidant glutathione or IL24-blocking antibody reversed the effects of NR4A1 inhibition, demonstrating the importance of both ROS and IL24 in mediating the cellular responses. IMPLICATIONS: Overall, these data elucidate the mechanism by which NR4A1 inhibition functions to inhibit the proliferation, survival, and migration of RMS cells.

Publication types

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

MeSH terms

  • Cell Line, Tumor
  • Cell Movement
  • Cell Proliferation
  • Cell Survival
  • Down-Regulation
  • Gene Expression Regulation, Neoplastic*
  • Glutathione / therapeutic use
  • Humans
  • Indoles / therapeutic use
  • Interleukins / antagonists & inhibitors
  • Interleukins / genetics
  • Interleukins / metabolism*
  • Isocitrate Dehydrogenase / genetics
  • Isocitrate Dehydrogenase / metabolism
  • Nuclear Receptor Subfamily 4, Group A, Member 1 / antagonists & inhibitors
  • Nuclear Receptor Subfamily 4, Group A, Member 1 / genetics
  • Nuclear Receptor Subfamily 4, Group A, Member 1 / metabolism*
  • Phenols / therapeutic use
  • Protein Disulfide-Isomerases / genetics
  • Protein Disulfide-Isomerases / metabolism
  • Reactive Oxygen Species / metabolism*
  • Rhabdomyosarcoma / genetics
  • Rhabdomyosarcoma / pathology
  • Rhabdomyosarcoma / therapy*


  • 1,1-bis(3'-indolyl)-1-(4-hydroxyphenyl)methane
  • Indoles
  • Interleukins
  • NR4A1 protein, human
  • Nuclear Receptor Subfamily 4, Group A, Member 1
  • Phenols
  • Reactive Oxygen Species
  • interleukin-24
  • Isocitrate Dehydrogenase
  • IDH1 protein, human
  • Protein Disulfide-Isomerases
  • TXNDC5 protein, human
  • Glutathione