Hsp90 Inhibitor SNX-2112 Enhances TRAIL-Induced Apoptosis of Human Cervical Cancer Cells via the ROS-Mediated JNK-p53-Autophagy-DR5 Pathway

Oxid Med Cell Longev. 2019 Mar 25:2019:9675450. doi: 10.1155/2019/9675450. eCollection 2019.

Abstract

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent cancer cell apoptosis-inducing factor that can induce apoptosis in a variety of cancer cells. However, resistance to TRAIL in cancer cells is a huge obstacle in creating effective TRAIL-targeted clinical therapies. Thus, agents that can either enhance the effect of TRAIL or overcome its resistance are needed. In this study, we combined TRAIL with SNX-2112, an Hsp90 inhibitor we previously developed, to explore the effect and mechanism that SNX-2112 enhanced TRAIL-induced apoptosis in cervical cancer cells. Our results showed that SNX-2112 markedly enhanced TRAIL-induced cytotoxicity in HeLa cells, and this combination was found to be synergistic. Additionally, we found that SNX-2112 sensitized TRAIL-mediated apoptosis caspase-dependently in TRAIL-resistant HeLa cells. Mechanismly, SNX-2112 downregulated antiapoptosis proteins, including Bcl-2, Bcl-XL, and FLIP, promoted the accumulation of reactive oxygen species (ROS), and increased the expression levels of p-JNK and p53. ROS scavenger NAC rescued SNX-2112/TRAIL-induced apoptosis and suppressed SNX-2112-induced p-JNK and p53. Moreover, SNX-2112 induced the upregulation of death-receptor DR5 in HeLa cells. The silencing of DR5 by siRNA significantly decreased cell apoptosis by the combined effect of SNX-2112 and TRAIL. In addition, SNX-2112 inhibited the Akt/mTOR signaling pathway and induced autophagy in HeLa cells. The blockage of autophagy by bafilomycin A1 or Atg7 siRNA abolished SNX-2112-induced upregulation of DR5. Meanwhile, ROS scavenger NAC, JNK inhibitor SP600125, and p53 inhibitor PFTα were used to verify that autophagy-mediated upregulation of DR5 was regulated by the SNX-2112-stimulated activation of the ROS-JNK-p53 signaling pathway. Thus, the combination of SNX-2112 and TRAIL may provide a novel strategy for the treatment of human cervical cancer by overcoming cellular mechanisms of apoptosis resistance.

MeSH terms

  • Apoptosis / drug effects*
  • Autophagy / drug effects*
  • Drug Synergism
  • Enzyme Activation / drug effects
  • Female
  • HSP90 Heat-Shock Proteins / antagonists & inhibitors*
  • HSP90 Heat-Shock Proteins / metabolism
  • HeLa Cells
  • Heterocyclic Compounds, 4 or More Rings / chemistry
  • Heterocyclic Compounds, 4 or More Rings / pharmacology*
  • Humans
  • MAP Kinase Signaling System / drug effects
  • Models, Biological
  • Proto-Oncogene Proteins c-akt / metabolism
  • Reactive Oxygen Species / metabolism*
  • Receptors, TNF-Related Apoptosis-Inducing Ligand / metabolism
  • TNF-Related Apoptosis-Inducing Ligand / pharmacology*
  • TOR Serine-Threonine Kinases / metabolism
  • Tumor Suppressor Protein p53 / metabolism*
  • Up-Regulation / drug effects
  • Uterine Cervical Neoplasms / pathology*

Substances

  • HSP90 Heat-Shock Proteins
  • Heterocyclic Compounds, 4 or More Rings
  • Reactive Oxygen Species
  • Receptors, TNF-Related Apoptosis-Inducing Ligand
  • SNX 2112
  • TNF-Related Apoptosis-Inducing Ligand
  • Tumor Suppressor Protein p53
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases