Synergistic antitumor activity of withaferin A combined with oxaliplatin triggers reactive oxygen species-mediated inactivation of the PI3K/AKT pathway in human pancreatic cancer cells

Cancer Lett. 2015 Feb 1;357(1):219-230. doi: 10.1016/j.canlet.2014.11.026. Epub 2014 Nov 18.

Abstract

Application of oxaliplatin for the treatment of pancreatic cancer (PC) is restricted owing to its toxic side effects and drug resistance. We investigated how withaferin A (WA), a bioactive component isolated from the medicinal plant Withania somnifera, acts synergistically with oxaliplatin on human PC in vitro and in vivo. We found that WA enhanced oxaliplatin-induced growth suppression and apoptosis in PC cells dramatically through a mechanism involving mitochondrial dysfunction and inactivation of the PI3K/AKT pathway. Combination treatment resulted in significant accumulation of intracellular reactive oxygen species (ROS). Pretreatment of cells with the ROS scavenger N-acetylcysteine completely blocked the apoptosis induced by combination treatment, and recovered expression of AKT inactivation, which revealed the important role of ROS in apoptosis and AKT regulation. In vivo, combination therapy showed the strongest anti-tumor effects compared with single agents, without obvious additional toxicity. These results support the notion that combination treatment with oxaliplatin and WA could facilitate development of an effective strategy for PC treatment.

Keywords: Apoptosis; Oxaliplatin; PI3K/AKT pathway; Pancreatic cancer; ROS; Withaferin A.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Combined Chemotherapy Protocols / pharmacology*
  • Apoptosis / drug effects
  • Drug Synergism
  • Humans
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Organoplatinum Compounds / administration & dosage
  • Organoplatinum Compounds / pharmacology*
  • Oxaliplatin
  • Pancreatic Neoplasms / drug therapy*
  • Pancreatic Neoplasms / enzymology
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Prognosis
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Random Allocation
  • Reactive Oxygen Species / metabolism
  • Signal Transduction
  • Withanolides / administration & dosage
  • Withanolides / pharmacology*

Substances

  • Organoplatinum Compounds
  • Reactive Oxygen Species
  • Withanolides
  • Oxaliplatin
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt
  • withaferin A