title: Tumor therapy mediated by lentiviral expression of shBcl-2 and S-TRAIL.
abstract: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively kill tumor cells and, in combination with other agents, could enhance tumor therapy. We explored the combined therapeutic effects of a secretable form of (S) TRAIL-induced apoptosis and the downregulation of Bcl-2 in human gliomas. We constructed a lentiviral delivery system: 1) for the expression of short hairpin (sh) RNA to downregulate Bcl-2 and for the expression of S-TRAIL to induce apoptosis in glioma cells; and 2) to follow delivery in vitro and the fate of tumors in real time in vivo. We demonstrate that lentiviral-mediated simultaneous downregulation of Bcl-2 and S-TRAIL-induced apoptosis leads to an increased expression of activated caspase-3 and caspase-7, thus resulting in accelerated S-TRAIL-mediated apoptosis in glioma cells in vitro. Using a highly malignant human glioma model expressing EGFRvIII and firefly luciferase, we show that the combined effect of Bcl-2 downregulation and S-TRAIL-induced apoptosis results in complete eradication of gliomas compared to S-TRAIL monotherapy. These results show that simultaneous triggering of TRAIL-mediated death receptor pathway and downregulation of Bcl-2 by shRNA leads to enhanced eradication of gliomas and serves as a template in developing and monitoring combination therapies for the treatment of drug-resistant cancers.
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
authors.forename: Norman
authors.initials: N
authors.lastname: Kock
authors.forename: Randa
authors.initials: R
authors.lastname: Kasmieh
authors.forename: Ralph
authors.initials: R
authors.lastname: Weissleder
authors.forename: Khalid
authors.initials: K
authors.lastname: Shah
mesh_terms: D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D045744:Cell Line, Tumor; D015536:Down-Regulation; D015316:Genetic Therapy; D005822:Genetic Vectors; D005910:Glioma / Q000473:pathology / Q000628:therapy*; D016086:Lentivirus / Q000235:genetics*; D051379:Mice; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000037:antagonists & inhibitors* / Q000235:genetics; D034622:RNA Interference; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics*
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D053221:TNF-Related Apoptosis-Inducing Ligand; D053148:Caspase 3; D053179:Caspase 7