Novel CHOP activator LGH00168 induces necroptosis in A549 human lung cancer cells via ROS-mediated ER stress and NF-κB inhibition

Acta Pharmacol Sin. 2016 Sep;37(10):1381-1390. doi: 10.1038/aps.2016.61. Epub 2016 Jun 6.


Aim: C/EBP homologous protein (CHOP) is a transcription factor that is activated at multiple levels during ER stress and plays an important role in ER stress-induced apoptosis. In this study we identified a novel CHOP activator, and further investigated its potential to be a therapeutic agent for human lung cancer.

Methods: HEK293-CHOP-luc reporter cells were used in high-throughput screening (HTS) to identify CHOP activators. The cytotoxicity against cancer cells in vitro was measured with MTT assay. The anticancer effects were further examined in A549 human non-small cell lung cancer xenograft mice. The mechanisms underlying CHOP activation were analyzed using luciferase assays, and the anticancer mechanisms were elucidated in A549 cells.

Results: From chemical libraries of 50 000 compounds, LGH00168 was identified as a CHOP activator, which showed cytotoxic activities against a panel of 9 cancer cell lines with an average IC50 value of 3.26 μmol/L. Moreover, administration of LGH00168 significantly suppressed tumor growth in A549 xenograft bearing mice. LGH00168 activated CHOP promoter via AARE1 and AP1 elements, increased DR5 expression, decreased Bcl-2 expression, and inhibited the NF-κB pathway. Treatment of A549 cells with LGH00168 (10 μmol/L) did not induce apoptosis, but lead to RIP1-dependent necroptosis, accompanied by cell swelling, plasma membrane rupture, lysosomal membrane permeabilization, MMP collapse and caspase 8 inhibition. Furthermore, LGH00168 (10 and 20 μmol/L) dose-dependently induced mito-ROS production in A549 cells, which was reversed by the ROS scavenger N-acetyl-L-cysteine (NAC, 10 mmol/L). Moreover, NAC significantly diminished LGH00168-induced CHOP activation, NF-κB inhibition and necroptosis in A549 cells.

Conclusion: LGH00168 is a CHOP activator that inhibits A549 cell growth in vitro and lung tumor growth in vivo.

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents / therapeutic use*
  • Apoptosis / drug effects*
  • Cell Line, Tumor / drug effects
  • Endoplasmic Reticulum Stress / drug effects
  • Humans
  • Lung Neoplasms / drug therapy*
  • Mice
  • Mice, Inbred BALB C
  • NF-kappa B / antagonists & inhibitors*
  • Necrosis
  • Pyrazines / pharmacology
  • Pyrazines / therapeutic use*
  • Pyrimidines / pharmacology
  • Pyrimidines / therapeutic use*
  • Reactive Oxygen Species / metabolism*


  • Antineoplastic Agents
  • LGH00168
  • NF-kappa B
  • Pyrazines
  • Pyrimidines
  • Reactive Oxygen Species