Enhanced apoptosis of glioma cell lines is achieved by co-delivering FasL-GFP and TRAIL with a complex Ad5 vector.
Brain tumors (BTs) are among the most malignant forms of human cancer. Unfortunately, current treatments are often ineffective and produce severe side effects. Cytotoxic gene therapy is an alternative treatment strategy, with the potential advantages of reduced toxicity to normal brain tissue. Apoptosis-inducing "death ligands" Fas ligand and TNF-related apoptosis-inducing ligand (TRAIL) are genes with substantial cytotoxic activity in susceptible tumor cells. Here, we compared the effectiveness of Ad vector-mediated delivery of Fas ligand-green fluorescent protein (FasL-GFP) fusion protein, human TRAIL, and both genes simultaneously. We examined a panel of 13 cell lines (eight derived from primary isolates) for susceptibility to Ad5-based vector infection and for sensitivity to FasL- and TRAIL-mediated apoptosis. All cell lines were efficiently transduced, but, as expected, varied in their sensitivity to ligand-induced apoptosis. Generally, sensitivity to FasL-GFP correlated with cell surface FasR levels, but no such correlation was seen for TRAIL and its functional receptors, DR4 and DR5. The vector expressing both FasL-GFP and TRAIL was more effective than either of the single-gene vectors at comparable transduction levels, and it was effective against a broader range of cell lines. In five cell lines, coexpression resulted in apoptosis levels greater than those predicted for strictly additive activity of the two death ligands. We believe that Ad vector-mediated delivery of multiple death ligands may be developed as a potential BT therapy, either alone or in conjunction with surgical resection of the primary tumor.
Rubinchik
Semyon
S
Department of Microbiology and Immunology, Medical University of South Carolina, 173 Ashley Avenue, BSB 201, Charleston, SC 29403, USA.
Yu
Hong
H
Woraratanadharm
Jan
J
Voelkel-Johnson
Christina
C
Norris
James S
JS
Dong
Jian-yun
JY
D000256:Adenoviridae / Q000235:genetics; D017209:Apoptosis / Q000235:genetics*; D051017:Apoptosis Regulatory Proteins; D001254:Astrocytoma / Q000235:genetics / Q000473:pathology / Q000628:therapy; D001932:Brain Neoplasms / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; D002352:Carrier Proteins / Q000378:metabolism; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D053222:Fas Ligand Protein; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics; D005910:Glioma / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D049452:Green Fluorescent Proteins; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008164:Luminescent Proteins / Q000235:genetics; D008562:Membrane Glycoproteins / Q000235:genetics*; D020033:Protein Isoforms; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000235:genetics / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand; D014161:Transduction, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
D051017:Apoptosis Regulatory Proteins; D053446:CASP8 and FADD-Like Apoptosis Regulating Protein; C506386:CFLAR protein, human; D002352:Carrier Proteins; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D047908:Intracellular Signaling Peptides and Proteins; D008164:Luminescent Proteins; D008562:Membrane Glycoproteins; D020033:Protein Isoforms; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D053221:TNF-Related Apoptosis-Inducing Ligand; C105190:TNFRSF10A protein, human; C505639:TNFRSF10B protein, human; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D049452:Green Fluorescent Proteins; C505530:CASP8 protein, human; D053181:Caspase 8; D020169:Caspases