title: Experimental studies on treatment of pancreatic cancer with double-regulated duplicative adenovirus AdTPHre-hEndo carrying human endostatin gene.
abstract: BACKGROUND
  Gene-virus targeted therapy is a promising new method of treating pancreatic cancer. To increase the efficacy and decrease the side-effect, we constructed a conditionally replicative adenovirus (CRAd) expressing human endostatin, with a human Telomoerase Reverse Transcriptase (hTERT) promoter for the regulation of the early stage of adenovirus expression of gene E1a and a Hypoxia Response Element (HRE) promoter to regulate the gene E1b.
  
  
  METHODS
  A gene recombination technique was adopted to construct and generate the adenovirus AdTPHre-hEndo. Pancreatic cancer cells were studied both in vitro and in vivo. Western blotting was adopted to observe the expressions of protein E1A and E1B; duplication assay was applied to observe the selective duplication capability of recombinant cells. MTT assay was applied to measure the lethal effects of virus on pancreatic cancer cells, and ELISA was adopted to detect the human endostatin gene expression. A pancreatic cancer transplantation tumor model of nude mice was constructed to observe the antitumor effects of the virus.
  
  
  RESULTS
  Double-regulated duplicative adenovirus AdTPHre-hEndo genes were successfully constructed. Duplication and lethal assays proved that AdTPHre-hEndo could replicate specifically in pancreatic cancer cells and kill them. The endostatin expression in a cultured supernatant from tumor cells was significantly higher than that obtained from non-duplicative adenovirus vectors carrying that gene. The animal experiment demonstrated that AdTPHre-hEndo has a high capability to limit pancreatic cancer growth.
  
  
  CONCLUSIONS
  AdTPHre-hEndo has a special ability to duplicate and kill pancreatic cancer cells in in vitro and in vivo experiments, thus providing a new gene-virus-based treatment system for pancreatic cancer.
authors.affiliation: Department of Surgery, First Affiliated Hospital, Wenzhou Medical College, Wenzhou 325000, Zhejiang Province, China.
authors.forename: Yun-feng
authors.initials: YF
authors.lastname: Shan
authors.forename: Yi-feng
authors.initials: YF
authors.lastname: Fang
authors.forename: Xue-qiang
authors.initials: XQ
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Jin
authors.forename: Qi-yu
authors.initials: QY
authors.lastname: Zhang
authors.forename: Roland
authors.initials: R
authors.lastname: Andersson
mesh_terms: D000256:Adenoviridae / Q000235:genetics* / Q000378:metabolism; D017500:Adenovirus E1A Proteins / Q000096:biosynthesis; D017501:Adenovirus E1B Proteins / Q000096:biosynthesis; D000818:Animals; D045744:Cell Line, Tumor; D043169:Endostatins / Q000096:biosynthesis; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D014779:Virus Replication; D023041:Xenograft Model Antitumor Assays
chemical_list: D017500:Adenovirus E1A Proteins; D017501:Adenovirus E1B Proteins; D043169:Endostatins
keywords: Adenovirus; Endostatin; Hypoxia response elements; Pancreatic cancer; Telomerase