Combination of gamma-interferon with TRAIL and cisplatin or etoposide induces apoptosis in human neuroblastoma cell line SH-SY5Y.
OBJECTIVE
To study the effect of gamma-interferon (IFNgamma), tumor necrosis factor related apoptosis inducing ligand (TRAIL), and cisplatin or etoposide induced apoptosis in human neuroblastoma cell line SH-SY5Y and its possible molecular mechanisms.


METHODS
The expressions of Caspase 8 mRNA and protein were detected with RT-PCR and Western blot analysis. The effects of IFN-gamma, TRAIL, IFNgamma + TRAIL, IFN-gamma + Caspase 8 inhibitor + TRAIL, IFNgamma + cisplatin + TRAIL, and IFNgamma + etoposide + TRAIL on the growth and apoptosis of SH-SY5Y cells were detected with the methods of MTT and flow cytometry. The relative Caspase 8 activity was measured with colorimetric assay.


RESULTS
Caspase 8 was undetectable in SH-SY5Y cells but an increased expression of Caspase 8 mRNA and protein was found after treatment with IFNgamma. SH-SY5Y cells themselves were not sensitive to TRAIL, but those expressing Caspase 8 after treatment with IFNgamma were. The killing effect of TRAIL on SH-SY5Y cells expressing Caspase 8 was depressed by Caspase 8 inhibitor. Cisplatin and etoposide could enhance the sensitivity of TRAIL on SH-SY5Y cells. The relative Caspase 8 activity of SH-SY5Y cells in IFN-gamma + TRAIL group was significantly higher than those of control group, IFN-gamma group, TRAIL group, and inhibitor group (P < 0.01). There was no significant difference among IFN-gamma + TRAIL group, IFNgamma + cisplatin + TRAIL group, and IFNgamma + etoposide + TRAIL group.


CONCLUSIONS
IFNgamma could sensitize SH-SY5Y cells to TRAIL-induced apoptosis and this may be realized by the up-regulation of Caspase 8. Cisplatin and etoposide could enhance the killing effect of TRAIL on SH-SY5Y cells.
Tong
Hai-Xia
HX
Laboratory of Hematology, Shengjing Hospital, China Medical University, Shenyang 110004.
Lu
Chun-Wei
CW
Zhang
Ji-Hong
JH
Ma
Li
L
Zhang
Jin-Hua
JH
D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D053181:Caspase 8 / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D005047:Etoposide / Q000494:pharmacology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D009447:Neuroblastoma / Q000201:enzymology / Q000235:genetics / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000494:pharmacology*
D000970:Antineoplastic Agents; D012333:RNA, Messenger; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D005047:Etoposide; D007371:Interferon-gamma; D053181:Caspase 8; D002945:Cisplatin