Overexpression of the orphan receptor Nur77 and its translocation induced by PCH4 may inhibit malignant glioma cell growth and induce cell apoptosis.
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.
Department of Life Science and Graduate Institute of Biotechnology, National Dong Hwa University, Hualien, Taiwan, ROC.
Li-Fu
LF
Chang
Po-Cheng
PC
Lin
Li-Ing
LI
Ho
Po-Yen
PY
Liu
Wan-Chen
WC
Wu
I-Ping
IP
Chiang
Hui-Wen
HW
Chang
Shinn-Zong
SZ
Lin
Yeu-Chern
YC
Harn
Horng-Jyh
HJ
Harn
Tzyy-Wen
TW
Chiou
D029971:Angelica sinensis / Q000737:chemistry; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001572:Benzofurans / Q000494:pharmacology*; D015153:Blotting, Western; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation / Q000187:drug effects*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D005021:Ethylamines / Q000494:pharmacology*; D005434:Flow Cytometry; D005909:Glioblastoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D048670:MAP Kinase Kinase 4 / Q000037:antagonists & inhibitors / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D057126:Nuclear Receptor Subfamily 4, Group A, Member 2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D010796:Phthalic Anhydrides / Q000737:chemistry / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects*; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D011987:Receptors, Steroid / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D011988:Receptors, Thyroid Hormone / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
D001572:Benzofurans; D004268:DNA-Binding Proteins; D005021:Ethylamines; C558309:N-(2-(dimethylamino)ethyl)-2-(3-((3-oxoisobenzofuran-1(3H)-ylidene)methyl)phenoxy)acetamide; C539882:NR4A2 protein, human; C490412:NR4A3 protein, human; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D057126:Nuclear Receptor Subfamily 4, Group A, Member 2; D010796:Phthalic Anhydrides; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D011987:Receptors, Steroid; D011988:Receptors, Thyroid Hormone; D008156:Luciferases; D048670:MAP Kinase Kinase 4; C026105:butylidenephthalide