title: The efficacy of combination therapy using adeno-associated virus-TRAIL targeting to telomerase activity and cisplatin in a mice model of hepatocellular carcinoma.
abstract: OBJECTIVE
  TNF-related apoptosis-inducing ligand (TRAIL) functions as a soluble cytokine and has been demonstrated significant antitumor activity against a variety of cancer cell lines without toxicity to most normal cells. Cisplatin is a potent anticancer agent and is widely used in the clinical for treatment of human cancers. Adeno-associated virus (AAV2) is a promising gene delivery vehicle for its advantage of low pathogenicity and long-term gene expression. However, lack of tissue specificity caused low efficiency of AAV transfer to target cells. The promoter of human telomerase reverse transcriptase (hTERT) is a good candidate to enhance targeting efficiency of AAV in cancer cells. Although AAV-mediated TRAIL controlled by hTERT promoter (AAV-hTERT-TRAIL) has obvious antitumor activity, the tumor cannot be completely eradicated. In this study, we first examined the effectiveness of combination therapy of cisplatin and AAV-hTERT-TRAIL on human hepatocellular carcinoma (HCC) in vitro and in vivo.
  
  
  METHODS
  For in vitro experiments, tumor cell lines were treated with cisplatin, virus, or both. The transgene TRAIL expression controlled by hTERT promoter was evaluated in BEL7404 HCC cell line. Cytotoxicity was performed by MTT analysis. Cell apoptosis was detected by flow cytometry analysis. The in vivo antitumor efficacy of combination treatment with cisplatin and AAV-hTERT-TRAIL was assessed in human hepatocellular carcinoma xenografts mouse model.
  
  
  RESULTS
  The enhanced TRAIL expression was observed in BEL7404 cells treated with AAV-hTERT-TRAIL plus cisplatin. Treatment with both AAV-hTERT-TRAIL and cisplatin exhibited stronger cytotoxicity and induced more significant apoptosis in cancer cells compared with AAV-hTERT-TRAIL or cisplatin alone, respectively. Moreover, in animal experiments, the combined treatment greatly suppressed tumor growth and resulted in tumor cell death.
  
  
  CONCLUSIONS
  AAV-mediated therapeutic gene expression in combination with chemotherapy provides a promising therapeutic strategy for human cancers. These data suggest that combined use of AAV-hTERT-TRAIL and cisplatin may have potential clinical application.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China. wangyigang43@163.com
authors.forename: Yigang
authors.initials: Y
authors.lastname: Wang
authors.forename: Fang
authors.initials: F
authors.lastname: Huang
authors.forename: Haibo
authors.initials: H
authors.lastname: Cai
authors.forename: Yumei
authors.initials: Y
authors.lastname: Wu
authors.forename: Guoqing
authors.initials: G
authors.lastname: He
authors.forename: Wen-Song
authors.initials: WS
authors.lastname: Tan
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D003131:Combined Modality Therapy; D000229:Dependovirus / Q000235:genetics; D005260:Female; D006801:Humans; D008114:Liver Neoplasms, Experimental / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D011401:Promoter Regions, Genetic / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics / Q000378:metabolism*; D019098:Telomerase / Q000235:genetics / Q000378:metabolism*; D014161:Transduction, Genetic; D047368:Tumor Burden / Q000187:drug effects / Q000235:genetics; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D053221:TNF-Related Apoptosis-Inducing Ligand; C509186:TERT protein, human; D019098:Telomerase; D002945:Cisplatin