Inhibition of NRF2 by PIK-75 augments sensitivity of pancreatic cancer cells to gemcitabine

Int J Oncol. 2014 Mar;44(3):959-69. doi: 10.3892/ijo.2013.2229. Epub 2013 Dec 23.

Abstract

We describe the potential benefit of PIK-75 in combination of gemcitabine to treat pancreatic cancer in a preclinical mouse model. The effect of PIK-75 on the level and activity of NRF2 was characterized using various assays including reporter gene, quantitative PCR, DNA-binding and western blot analyses. Additionally, the combinatorial effect of PIK-75 and gemcitabine was evaluated in human pancreatic cancer cell lines and a xenograft model. PIK-75 reduced NRF2 protein levels and activity to regulate its target gene expression through proteasome-mediated degradation of NRF2 in human pancreatic cancer cell lines. PIK-75 also reduced the gemcitabine-induced NRF2 levels and the expression of its downstream target MRP5. Co-treatment of PIK-75 augmented the antitumor effect of gemcitabine both in vitro and in vivo. Our present study provides a strong mechanistic rationale to evaluate NRF2 targeting agents in combination with gemcitabine to treat pancreatic cancers.

Publication types

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

MeSH terms

  • Animals
  • Antineoplastic Combined Chemotherapy Protocols / administration & dosage*
  • Cell Line, Tumor
  • Deoxycytidine / administration & dosage
  • Deoxycytidine / analogs & derivatives
  • Gemcitabine
  • Humans
  • Hydrazones / administration & dosage*
  • Mice
  • NF-E2-Related Factor 2 / antagonists & inhibitors*
  • NF-E2-Related Factor 2 / genetics
  • Pancreatic Neoplasms / drug therapy
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / pathology
  • Sulfonamides / administration & dosage*
  • Xenograft Model Antitumor Assays

Substances

  • Hydrazones
  • NF-E2-Related Factor 2
  • NFE2L2 protein, human
  • PIK 75
  • Sulfonamides
  • Deoxycytidine
  • Gemcitabine