Role of caspase 8 as a determinant in trail sensitivity of neuroblastoma cell lines.
OBJECTIVE
Resistance of neuroblastoma (NB) cells to tumor necrosis factor-related apoptosis inducing ligand (TRAIL)-mediated apoptosis is thought to be caused by loss of caspase 8 expression. The aim of this study is to investigate if induction of caspase 8 by gamma-interferon (IFN gamma) renders NB cells sensitive to TRAIL.


METHODS
Caspase 8 expression was monitored by RT-PCR and Western blot analysis. The effects of IFN gamma, TRAIL, IFN gamma + TRAIL, and caspase 8 inhibitor + TRAIL on the growth and apoptosis of NB cells were detected with the methods of reduction rate of Alamar blue assay and flow cytometry. The relative caspase 8 activity was measured with colorimetric assay.


RESULTS
An increased expression of caspase 8 mRNA and protein was found after treatment with IFN gamma. IFN gamma in combination with TRAIL decreased proliferation of NB cell line SH-SY5Y cells. The killing effect of TRAIL on NB cells expressing caspase 8 was depressed by caspase 8 inhibitor. The relative caspase 8 activity of NB cells expressing caspase 8 increased with the prolongation of TRAIL action time.


CONCLUSIONS
TRAIL induced apoptosis in NB cells expressing caspase 8.
Tong
Haixia
H
Laboratory of Hematology, Shengjing Hospital of China Medical University, Shenyang, China. tonghaixia18@yahoo.com.cn
Lu
Chunwei
C
Yang
Yanmin
Y
Zhang
Jihong
J
Zhang
Jinhua
J
D017209:Apoptosis / Q000187:drug effects; D053181:Caspase 8 / Q000032:analysis* / Q000235:genetics / Q000502:physiology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D009447:Neuroblastoma / Q000188:drug therapy* / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000494:pharmacology*; D015533:Transcriptional Activation
D012333:RNA, Messenger; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D007371:Interferon-gamma; D053181:Caspase 8