Inhibitory effect of Par-4 combined with cisplatin on human Wilms' tumor cells

Tumour Biol. 2017 Jul;39(7):1010428317716689. doi: 10.1177/1010428317716689.

Abstract

Wilms' tumor is associated with a high treatment success rate, but there is still a risk of recurrence. Cisplatin, which is one of the chemotherapeutic agents used for its treatment, is associated with a very high rate of resistance. Par-4 (prostate apoptosis response 4) is a tumor suppressor, which is capable of sensitizing tumor cells to chemotherapy. Therefore, the aim of this study was to determine whether combined treatment with Par-4 and cisplatin is effective for inhibiting growth of Wilms' tumor. Wilms' tumor and control cell samples were collected and analyzed by immunofluorescence assay and immunohistochemistry. Total proteins extracted from cultured cells were analyzed using western blotting and flow cytometry. In addition, a mouse xenograft model was established. We discovered significantly low expression of Par-4 in the tumor tissue, which was positively correlated with high expression of GRP78 (glucose-regulated protein 78). In addition, we found that ectopic Par-4 co-localized with cell surface GRP78 and induced high expression of the endoplasmic reticulum proteins ATF4 and BAX, which activated the endoplasmic reticulum apoptosis pathway. Moreover, treatment with ectopic Par-4 and cisplatin suppressed xenograft growth in nude mice. In conclusion, our results showed that Par-4 overexpression and cisplatin had a synergistic effect on SK-NEP-1 cells, as a result of which cell growth was inhibited and cellular apoptosis was induced. Thus, in vitro and in vivo upregulation of Par-4 expression is indispensable for the trafficking of GRP78 to the cell membrane and subsequent apoptosis of cancer cells.

Keywords: Nephroblastoma; apoptosis; cisplatin; glucose-regulated protein 78; prostate apoptosis response 4.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis Regulatory Proteins / administration & dosage
  • Apoptosis Regulatory Proteins / genetics*
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cisplatin / administration & dosage
  • Drug Resistance, Neoplasm / genetics
  • Endoplasmic Reticulum / drug effects
  • Endoplasmic Reticulum / genetics
  • Endoplasmic Reticulum Chaperone BiP
  • Gene Expression Regulation, Neoplastic / drug effects
  • Heat-Shock Proteins / biosynthesis
  • Heat-Shock Proteins / genetics*
  • Humans
  • Mice
  • Signal Transduction / drug effects
  • Transfection
  • Wilms Tumor / drug therapy*
  • Wilms Tumor / genetics
  • Wilms Tumor / pathology
  • Xenograft Model Antitumor Assays

Substances

  • Apoptosis Regulatory Proteins
  • Endoplasmic Reticulum Chaperone BiP
  • HSPA5 protein, human
  • Heat-Shock Proteins
  • Hspa5 protein, mouse
  • prostate apoptosis response-4 protein
  • Cisplatin