title: Enhancement of Ad5-TRAIL cytotoxicity against renal cell carcinoma with histone deacetylase inhibitors.
abstract: Renal cell carcinoma (RCC) will cause greater than 12,000 deaths in the United States this year. The lack of effective therapy for disseminated RCC has stimulated the search for novel treatments including immunotherapeutic strategies, but poor therapeutic responses and marked toxicity have limited their use. The tumor necrosis factor (TNF) family member TNF-related apoptosis-inducing ligand (TRAIL)/Apo-2L induces apoptosis in various tumor cell types, while having little cytotoxicity against normal cells. In this study, we investigated the tumoricidal potential of a recombinant adenovirus encoding human TNFSF10 (Ad5-TRAIL), alone and in combination with a panel of histone deacetylase inhibitors (HDACi), against the TRAIL/Apo-2L-resistant RCC line 786-O and normal human renal proximal tubule epithelial cells (RPTEC). Ad5-TRAIL was unable to induce apoptosis in either 786-O or RPTEC alone; however, tumor cell apoptosis occurred when Ad5-TRAIL was combined with HDAC inhibition. Except when combined with trichostatin A, RPTEC were not sensitized to Ad5-TRAIL by HDACi. In 786-O, HDAC inhibition induced CAR expression, permitting increased adenoviral infection and transgene expression. It also induced TRAIL-R2 expression, accelerated the death-inducing signaling complex formation and enhanced caspase-8 activation. Our results demonstrate the utility of combining Ad5-TRAIL with HDACi against RCC, and mechanistically define how this combination modulates RCC sensitivity to TRAIL/Apo-2L and adenoviral infection.
authors.affiliation: Department of Urology, University of Iowa, Iowa City, IA 52242-1089, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: VanOosten
authors.forename: J K
authors.initials: JK
authors.lastname: Earel
authors.forename: T S
authors.initials: TS
authors.lastname: Griffith
mesh_terms: D000256:Adenoviridae / Q000145:classification / Q000235:genetics; D000970:Antineoplastic Agents / Q000008:administration & dosage; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000008:administration & dosage / Q000235:genetics*; D002292:Carcinoma, Renal Cell / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D003131:Combined Modality Therapy; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage* / Q000235:genetics; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000235:genetics; D006801:Humans; D007680:Kidney Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D008562:Membrane Glycoproteins / Q000008:administration & dosage / Q000235:genetics*; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage / Q000235:genetics*
chemical_list: D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D008562:Membrane Glycoproteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; C505530:CASP8 protein, human; D053181:Caspase 8; D020169:Caspases; D006655:Histone Deacetylases