Mitochondrial inhibitor sensitizes non-small-cell lung carcinoma cells to TRAIL-induced apoptosis by reactive oxygen species and Bcl-X(L)/p53-mediated amplification mechanisms

Cell Death Dis. 2014 Dec 18;5(12):e1579. doi: 10.1038/cddis.2014.547.

Abstract

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising agent for anticancer therapy; however, non-small-cell lung carcinoma (NSCLC) cells are relatively TRAIL resistant. Identification of small molecules that can restore NSCLC susceptibility to TRAIL-induced apoptosis is meaningful. We found here that rotenone, as a mitochondrial respiration inhibitor, preferentially increased NSCLC cells sensitivity to TRAIL-mediated apoptosis at subtoxic concentrations, the mechanisms by which were accounted by the upregulation of death receptors and the downregulation of c-FLIP (cellular FLICE-like inhibitory protein). Further analysis revealed that death receptors expression by rotenone was regulated by p53, whereas c-FLIP downregulation was blocked by Bcl-X(L) overexpression. Rotenone triggered the mitochondria-derived reactive oxygen species (ROS) generation, which subsequently led to Bcl-X(L) downregulation and PUMA upregulation. As PUMA expression was regulated by p53, the PUMA, Bcl-X(L) and p53 in rotenone-treated cells form a positive feedback amplification loop to increase the apoptosis sensitivity. Mitochondria-derived ROS, however, promote the formation of this amplification loop. Collectively, we concluded that ROS generation, Bcl-X(L) and p53-mediated amplification mechanisms had an important role in the sensitization of NSCLC cells to TRAIL-mediated apoptosis by rotenone. The combined TRAIL and rotenone treatment may be appreciated as a useful approach for the therapy of NSCLC that warrants further investigation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis Regulatory Proteins / genetics
  • Apoptosis Regulatory Proteins / metabolism
  • CASP8 and FADD-Like Apoptosis Regulating Protein / genetics
  • CASP8 and FADD-Like Apoptosis Regulating Protein / metabolism
  • Carcinoma, Non-Small-Cell Lung / drug therapy
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Carcinoma, Non-Small-Cell Lung / physiopathology
  • Cell Line, Tumor
  • Humans
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / physiopathology
  • Mice
  • Mitochondria / drug effects*
  • Mitochondria / metabolism
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • Reactive Oxygen Species / metabolism*
  • Rotenone / administration & dosage
  • Rotenone / pharmacology*
  • TNF-Related Apoptosis-Inducing Ligand / administration & dosage
  • TNF-Related Apoptosis-Inducing Ligand / metabolism*
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism*
  • bcl-X Protein / genetics
  • bcl-X Protein / metabolism*

Substances

  • Apoptosis Regulatory Proteins
  • BBC3 protein, human
  • CASP8 and FADD-Like Apoptosis Regulating Protein
  • CFLAR protein, human
  • Proto-Oncogene Proteins
  • Reactive Oxygen Species
  • TNF-Related Apoptosis-Inducing Ligand
  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • bcl-X Protein
  • Rotenone