Overexpression of the orphan receptor Nur77 and its translocation induced by PCH4 may inhibit malignant glioma cell growth and induce cell apoptosis

J Surg Oncol. 2011 Apr;103(5):442-50. doi: 10.1002/jso.21809. Epub 2011 Jan 18.

Abstract

Background: In previous study, n-butylidenephthalide (BP), a natural compound from Angelica sinensis, has anti-glioblastoma multiform (GBM) cell effects. In this study, we modified BP structure to increase anti-GBM cell effects. The anti-GBM cell effects of one derivative of BP, (Z)-N-(2-(dimethylamino)ethyl)-2-(3-((3-oxoisobenzofuran-1(3H)-ylidene)methyl)phenoxy)acetamide (PCH4) were tested in vitro and in vivo.

Methods: MTT assay and PI/Annexin V assay were performed to evaluate the anti-GBM effects of PCH4. The Nur77 expression and translocation were assayed by RT-PCR and Western blot. The Nur77 siRNA was used to downregulate the Nur77 expression. The JNK inhibitor (SP600125) was used to block the JNK pathway.

Results: The anti-GBM effect of PCH4 is four times more than BP. The IC(50) of PCH4 on DBTRG-05MG cells was 50 µg/ml. Nur77 expression and translocation from the nucleus to the cytoplasm were important in PCH4-induced apoptosis. Furthermore, the downregulation of PCH4-induced Nur77 expression by Nur77 siRNA reduced PCH4-induced apoptosis. In addition, PCH4-induced apoptosis was associated with the JNK pathway. The JNK inhibitor, SP600125, inhibited Nur77 mRNA expression and reduced PCH4-induced apoptosis.

Conclusions: In conclusion, PCH4, a derivative of BP, induced Nur77-mediated apoptosis via the JNK pathway and this mechanism, which is different from that of BP, may explain the increase in the anti-tumor effects on GBM.

MeSH terms

  • Angelica sinensis / chemistry
  • Animals
  • Apoptosis / drug effects*
  • Benzofurans / pharmacology*
  • Blotting, Western
  • Brain Neoplasms / drug therapy*
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology
  • Cell Proliferation / drug effects*
  • DNA-Binding Proteins / antagonists & inhibitors
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Ethylamines / pharmacology*
  • Flow Cytometry
  • Glioblastoma / drug therapy*
  • Glioblastoma / metabolism
  • Glioblastoma / pathology*
  • Humans
  • Luciferases / metabolism
  • MAP Kinase Kinase 4 / antagonists & inhibitors
  • MAP Kinase Kinase 4 / metabolism
  • Mice
  • Mice, Nude
  • Nuclear Receptor Subfamily 4, Group A, Member 1 / antagonists & inhibitors
  • Nuclear Receptor Subfamily 4, Group A, Member 1 / genetics
  • Nuclear Receptor Subfamily 4, Group A, Member 1 / metabolism*
  • Nuclear Receptor Subfamily 4, Group A, Member 2 / antagonists & inhibitors
  • Nuclear Receptor Subfamily 4, Group A, Member 2 / genetics
  • Nuclear Receptor Subfamily 4, Group A, Member 2 / metabolism
  • Phthalic Anhydrides / chemistry
  • Phthalic Anhydrides / pharmacology
  • Protein Transport / drug effects*
  • RNA, Messenger / genetics
  • RNA, Small Interfering / genetics
  • Receptors, Steroid / antagonists & inhibitors
  • Receptors, Steroid / genetics
  • Receptors, Steroid / metabolism
  • Receptors, Thyroid Hormone / antagonists & inhibitors
  • Receptors, Thyroid Hormone / genetics
  • Receptors, Thyroid Hormone / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays

Substances

  • Benzofurans
  • DNA-Binding Proteins
  • Ethylamines
  • N-(2-(dimethylamino)ethyl)-2-(3-((3-oxoisobenzofuran-1(3H)-ylidene)methyl)phenoxy)acetamide
  • NR4A2 protein, human
  • NR4A3 protein, human
  • Nuclear Receptor Subfamily 4, Group A, Member 1
  • Nuclear Receptor Subfamily 4, Group A, Member 2
  • Phthalic Anhydrides
  • RNA, Messenger
  • RNA, Small Interfering
  • Receptors, Steroid
  • Receptors, Thyroid Hormone
  • Luciferases
  • MAP Kinase Kinase 4
  • butylidenephthalide