Regorafenib induces extrinsic and intrinsic apoptosis through inhibition of ERK/NF-κB activation in hepatocellular carcinoma cells

Oncol Rep. 2017 Feb;37(2):1036-1044. doi: 10.3892/or.2016.5328. Epub 2016 Dec 20.

Abstract

The aim of the present study was to investigate the role of NF-κB inactivation in regorafenib-induced apoptosis in human hepatocellular carcinoma SK-HEP-1 cells. SK-HEP-1 cells were treated with different concentrations of the NF-κB inhibitor 4-N-[2-(4-phenoxyphenyl)ethyl]quinazoline-4,6-diamine (QNZ) or regorafenib for different periods. The effects of QNZ and regorafenib on cell viability, expression of NF-κB-modulated anti-apoptotic proteins and apoptotic pathways were analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, western blotting, DNA gel electrophoresis, flow cytometry and NF-κB reporter gene assay. Inhibitors of various kinases including AKT, c-Jun N-terminal kinase (JNK), P38 and extracellular signal-regulated kinase (ERK) were used to evaluate the mechanism of regorafenib-induced NF-κB inactivation. The results demonstrated that both QNZ and regorafenib significantly inhibited the expression of anti-apoptotic proteins and triggered extrinsic and intrinsic apoptosis. We also demonstrated that regorafenib inhibited NF-κB activation through ERK dephosphorylation. Taken all together, our findings indicate that regorafenib triggers extrinsic and intrinsic apoptosis through suppression of ERK/NF-κB activation in SK-HEP-1 cells.

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Apoptosis / drug effects*
  • Apoptosis / physiology
  • Carcinoma, Hepatocellular / drug therapy*
  • Carcinoma, Hepatocellular / metabolism
  • Carcinoma, Hepatocellular / pathology
  • Cell Line, Tumor
  • Enzyme Activation / drug effects
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Humans
  • Liver Neoplasms / drug therapy*
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / pathology
  • Membrane Potential, Mitochondrial / drug effects
  • NF-kappa B / antagonists & inhibitors
  • NF-kappa B / genetics
  • NF-kappa B / metabolism*
  • Phenyl Ethers / pharmacology
  • Phenylurea Compounds / pharmacology*
  • Phosphorylation / drug effects
  • Pyridines / pharmacology*
  • Quinazolines / pharmacology
  • X-Linked Inhibitor of Apoptosis Protein / metabolism

Substances

  • Antineoplastic Agents
  • EVP 4593
  • NF-kappa B
  • Phenyl Ethers
  • Phenylurea Compounds
  • Pyridines
  • Quinazolines
  • X-Linked Inhibitor of Apoptosis Protein
  • XIAP protein, human
  • regorafenib
  • Extracellular Signal-Regulated MAP Kinases