Endoplasmic reticulum stress-mediated autophagy protects against β,β-dimethylacrylshikonin-induced apoptosis in lung adenocarcinoma cells

Cancer Sci. 2018 Jun;109(6):1889-1901. doi: 10.1111/cas.13616. Epub 2018 May 19.

Abstract

β,β-Dimethylacrylshikonin (DMAS) is an anti-cancer compound extracted from the roots of Lithospermum erythrorhizon. The present study aims to investigate the effects of DMAS on human lung adenocarcinoma cells in vitro and explore the mechanisms of its anti-cancer action. We showed that DMAS markedly inhibited cell viability in a dose- and time-dependent way, and induced apoptosis as well as autophagy in human lung adenocarcinoma cells. Furthermore, we found that DMAS stimulated endoplasmic reticulum stress and mediated autophagy through the PERK-eIF2α-ATF4-CHOP and IRE1-TRAF2-JNK axes of the unfolded protein response in human lung adenocarcinoma cells. We also showed that the autophagy induced by DMAS played a prosurvival role in human lung adenocarcinoma cells and attenuated the apoptotic cascade. Collectively, combined treatment of DMAS and pharmacological autophagy inhibitors could offer an effective therapeutic strategy for lung adenocarcinoma treatment.

Keywords: apoptosis; autophagy; endoplasmic reticulum stress; lung adenocarcinoma; β,β-dimethylacrylshikonin.

MeSH terms

  • A549 Cells
  • Adenocarcinoma / genetics
  • Adenocarcinoma / metabolism
  • Adenocarcinoma / pathology
  • Apoptosis / drug effects*
  • Autophagy / drug effects*
  • Autophagy / genetics
  • Autophagy-Related Protein 5 / genetics
  • Autophagy-Related Protein 5 / metabolism
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cell Survival / genetics
  • Endoplasmic Reticulum Stress / drug effects*
  • Humans
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology
  • Naphthoquinones / pharmacology*
  • RNA Interference
  • Signal Transduction / drug effects
  • Signal Transduction / genetics
  • Transcription Factor CHOP / genetics
  • Transcription Factor CHOP / metabolism
  • Unfolded Protein Response / drug effects

Substances

  • ATG5 protein, human
  • Autophagy-Related Protein 5
  • DDIT3 protein, human
  • Naphthoquinones
  • Transcription Factor CHOP
  • beta, beta-dimethylacrylshikonin