Ciclopirox induces autophagy through reactive oxygen species-mediated activation of JNK signaling pathway

Oncotarget. 2014 Oct 30;5(20):10140-50. doi: 10.18632/oncotarget.2471.

Abstract

Ciclopirox olamine (CPX), a fungicide, has been demonstrated as a potential anticancer agent. However, the underlying anticancer mechanism is not well understood. Here, we found that CPX induced autophagy in human rhabdomyosarcoma (Rh30 and RD) cells. It appeared that CPX-induced autophagy was attributed to induction of reactive oxygen species (ROS), as N-acetyl-L-cysteine (NAC), a ROS scavenger and antioxidant, prevented this process. Furthermore, we observed that CPX induced activation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38 MAPK, which was also blocked by NAC. However, only inhibition of JNK (with SP600125) or expression of dominant negative c-Jun partially prevented CPX-induced autophagy, indicating that ROS-mediated activation of JNK signaling pathway contributed to CPX-induced autophagy. Of interest, inhibition of autophagy by chloroquine (CQ) enhanced CPX-induced cell death, indicating that CPX-induced autophagy plays a pro-survival role in human rhabdomyosarcoma cells. Our finding suggests that the combination with autophagy inhibitors may be a novel strategy in potentiating the anticancer activity of CPX for treatment of rhabdomyosarcoma.

Publication types

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

MeSH terms

  • Antifungal Agents / pharmacology
  • Antineoplastic Agents / pharmacology
  • Autophagy / drug effects
  • Cell Line, Tumor
  • Ciclopirox
  • Humans
  • JNK Mitogen-Activated Protein Kinases / metabolism*
  • MAP Kinase Signaling System / drug effects*
  • Pyridones / pharmacology*
  • Reactive Oxygen Species / metabolism*
  • Rhabdomyosarcoma / drug therapy*
  • Rhabdomyosarcoma / enzymology
  • Rhabdomyosarcoma / pathology

Substances

  • Antifungal Agents
  • Antineoplastic Agents
  • Pyridones
  • Reactive Oxygen Species
  • Ciclopirox
  • JNK Mitogen-Activated Protein Kinases