Autophagy inhibition sensitizes hepatocellular carcinoma to the multikinase inhibitor linifanib

Sci Rep. 2014 Oct 20:4:6683. doi: 10.1038/srep06683.

Abstract

Autophagy is a critical survival pathway for cancer cells under conditions of stress. Thus, induction of autophagy has emerged as a drug resistance mechanism. This study is to determine whether autophagy is activated by a novel multikinase inhibitor linifanib, thereby impairing the sensitivity of hepatocellular carcinoma (HCC) cells to this targeted therapy. Here, we found that linifanib induced a high level of autophagy in HCC cells, which was accompanied by suppression of phosphorylation of PDGFR-β and its downstream Akt/mTOR and Mek/Erk signaling pathways. Cell death induced by linifanib was greatly enhanced after autophagy inhibition by the pharmacological inhibitors or siRNAs against autophagy related genes, ATG5 and ATG7, in vitro. Moreover, HCQ, an FDA-approved drug used to inhibit autophagy, could significantly augment the anti-HCC effect of linifanib in a mouse xenograft model. In conclusion, linifanib can induce cytoprotective autophagy by suppression of PDGFR-β activities in HCC cells. Thus, autophagy inhibition represents a promising approach to improve the efficacy of linifanib in the treatment of HCC patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy / genetics*
  • Carcinoma, Hepatocellular / drug therapy*
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / pathology
  • Cell Survival / drug effects
  • Drug Resistance, Neoplasm / drug effects
  • Hep G2 Cells
  • Humans
  • Indazoles / administration & dosage*
  • Liver Neoplasms / drug therapy*
  • Liver Neoplasms / genetics
  • Liver Neoplasms / pathology
  • Mice
  • Phenylurea Compounds / administration & dosage*
  • Signal Transduction / drug effects
  • Xenograft Model Antitumor Assays

Substances

  • Indazoles
  • Phenylurea Compounds
  • linifanib