Resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in neuroblastoma cells correlates with a loss of caspase-8 expression.
Disruption of apoptotic pathways may be involved in tumor formation, regression, and treatment resistance of neuroblastoma (NB). Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent inducer of apoptosis in cancer cell lines, whereas normal cells are not sensitive to TRAIL-mediated apoptosis. In this study we analyzed the expression and function of TRAIL and its agonistic and antagonistic receptors as well as expression of cellular FLICE-like inhibitory protein and caspase-2, -3, -8, -9, and -10 in 18 NB cell lines. Semiquantitative RT-PCR revealed that TRAIL-R2 and TRAIL-R3 are the main TRAIL-receptors used by NB cells. Sensitivity to TRAIL-induced apoptosis did not correlate with mRNA expression of TRAIL receptors or cellular FLICE-like inhibitory protein. Surprisingly, caspase-8 and caspase-10 mRNA expression was detected in only 5 of 18 NB cell lines. Interestingly, only these five NB cell lines were susceptible to TRAIL-induced apoptosis in a time- and dose-dependent manner. Treatment with 5-aza-2'-deoxycytidine restored mRNA and protein expression of caspase-8 and TRAIL sensitivity of resistant cell lines, suggesting that gene methylation is involved in caspase inactivation. The TRAIL system seems to be functional in NB cells expressing caspase-8 and/or caspase-10. Because many cytotoxic drugs induce caspase-dependent apoptosis, failure to express caspase-8 and/or caspase-10 might be an important mechanism of resistance to chemotherapy in NB.
Division of Oncology, The Children's Hospital of Philadelphia, Pennsylvania 19104, USA.
A
A
Eggert
M A
MA
Grotzer
T J
TJ
Zuzak
B R
BR
Wiewrodt
R
R
Ho
N
N
Ikegaki
G M
GM
Brodeur
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D051017:Apoptosis Regulatory Proteins; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D053455:Caspase 10; D053181:Caspase 8; D053453:Caspase 9; D061945:Caspase Inhibitors; D020169:Caspases / Q000096:biosynthesis* / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D000077209:Decitabine; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D058851:GPI-Linked Proteins; D006801:Humans; D019169:Jurkat Cells / Q000166:cytology / Q000187:drug effects; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000494:pharmacology*; D008745:Methylation; D009447:Neuroblastoma / Q000201:enzymology* / Q000473:pathology*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis; D053320:Receptors, Tumor Necrosis Factor, Member 10c; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053221:TNF-Related Apoptosis-Inducing Ligand; D053319:Tumor Necrosis Factor Decoy Receptors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000494:pharmacology*
D000590:Amino Acid Chloromethyl Ketones; D051017:Apoptosis Regulatory Proteins; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D004791:Enzyme Inhibitors; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D053320:Receptors, Tumor Necrosis Factor, Member 10c; D053221:TNF-Related Apoptosis-Inducing Ligand; C105190:TNFRSF10A protein, human; C505639:TNFRSF10B protein, human; C108661:TNFRSF10C protein, human; C505653:TNFSF10 protein, human; D053319:Tumor Necrosis Factor Decoy Receptors; D014409:Tumor Necrosis Factor-alpha; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D000077209:Decitabine; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053455:Caspase 10; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; C506438:CASP10 protein, human; D001374:Azacitidine