Glioma cells deficient in urokinase plaminogen activator receptor expression are susceptible to tumor necrosis factor-alpha-related apoptosis-inducing ligand-induced apoptosis.
OBJECTIVE
The urokinase plasminogen activation system comprises the ligand urokinase plasminogen activator and the receptor urokinase plasminogen activator receptor (uPAR), which play an important role in the activation of matrix-degrading enzymes that enhance the invasion of cancer cells. Earlier studies have indicated that SNB19 glioblastoma cells expressing antisense uPAR constructs lose their invasive properties when injected in vivo. Additional observations indicated that injected antisense uPAR:SNB19 cells were being lost through apoptotic elimination.


METHODS
SNB19, Vector, and SNB19:asuPAR were analyzed to determine cytotoxicity of tumor necrosis factor-alpha-related apoptosis-inducing ligand (TRAIL), receptor expression, and underlying signaling pathways using flow cytometry, immunohistochemistry, RNase protection assay, and c-Jun-NH(2)-terminal kinase activity.


RESULTS
This study elucidated the susceptibility of antisense uPAR:SNB19 cells to TRAIL under certain experimental conditions in vitro. These uPAR-deficient transfected cells had higher levels of the TRAIL receptors DR4 and DR5 than did the control and vector population as detected by flow cytometry. An RNase protection assay confirmed the elevation of DR4 and DR5 mRNA in the antisense uPAR cells.


CONCLUSIONS
These findings provide preliminary evidence of a link between TRAIL-induced apoptosis and cell cycle progression in antisense uPAR:SNB 19 cells.
Krishnamoorthy
B
B
Division of Cancer Biology, Department of Biomedical and Therapeutic Sciences, University of Illinois College of Medicine, Peoria, IL 61656, USA.
Darnay
B
B
Aggarwal
B
B
Dinh
D H
DH
Kouraklis
G
G
Olivero
W C
WC
Gujrati
M
M
Rao
J S
JS
D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D002470:Cell Survival / Q000187:drug effects; D003513:Cycloheximide / Q000494:pharmacology; D005434:Flow Cytometry; D005822:Genetic Vectors; D005910:Glioma; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D007700:Kinetics; D008024:Ligands; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000172:deficiency / Q000235:genetics*; D055293:Receptors, Urokinase Plasminogen Activator; D015398:Signal Transduction; D053221:TNF-Related Apoptosis-Inducing Ligand; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D051017:Apoptosis Regulatory Proteins; D008024:Ligands; D008562:Membrane Glycoproteins; D020319:Oligodeoxyribonucleotides, Antisense; C524898:PLAUR protein, human; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D003513:Cycloheximide; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases