Exploiting the differential production of angiogenic factors within the tumor microenvironment in the design of a novel vascular-targeted gene therapy-based approach to the treatment of cancer.
OBJECTIVE
The aim of this study is to explore a novel strategy through which the differential production of pro-angiogenic cytokines within the tumor microenvironment can be exploited as a means of selectively killing the vascular endothelial cells upon which the survival and growth of a tumor depend.


METHODS
Adenoviral vectors encoding a chimeric cell surface receptor composed of the extracellular domain of the vascular endothelial growth factor (VEGF) receptor Flk-1/KDR fused in frame to the membrane spanning and cytoplasmic domain of Fas were constructed and used to transduce primary human endothelial cells in vitro. The apoptotic response of these cells induced upon ligation of the chimeric receptor with VEGF was determined by measuring caspase-3 activation, AnnexinV-FITC binding, and the release of glucose-6-phosphate dehydrogenase.


RESULTS
The chimeric Flk-1/Fas protein is stable and expressed at high levels on the surface of adenovirally transduced cells. Upon the addition of exogenous VEGF, these cells undergo rapid apoptosis.


CONCLUSIONS
Receptor/Fas chimeras that recognize and bind pro-angiogenic cytokines represent a novel means by which the signal transduction events normally triggered in vascular endothelial cells upon the binding of angiogenic cytokines may be redirected toward the induction of apoptotic cell death. It is proposed that these constructs will prove of value in the further development of safe and effective vascular-targeted gene therapy-based approaches to the treatment of cancer.
Carpenito
Carmine
C
Department of Radiation Oncology, UCLA Medical Center, Los Angeles, CA 90095-1714, USA
Davis
Peter D
PD
Dougherty
Shona T
ST
Dougherty
Graeme J
GJ
D000256:Adenoviridae / Q000235:genetics; D017209:Apoptosis; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002469:Cell Separation; D002478:Cells, Cultured; D016207:Cytokines / Q000627:therapeutic use*; D018076:DNA, Complementary / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D005434:Flow Cytometry; D015316:Genetic Therapy / Q000379:methods*; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D006801:Humans; D008024:Ligands; D009369:Neoplasms / Q000628:therapy*; D009389:Neovascularization, Pathologic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism
D016207:Cytokines; D018076:DNA, Complementary; D008024:Ligands; D011993:Recombinant Fusion Proteins; D019014:fas Receptor; D005954:Glucosephosphate Dehydrogenase; D040301:Vascular Endothelial Growth Factor Receptor-2; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases