title: Overexpression of tumor suppressor TSLC1 by a survivin-regulated oncolytic adenovirus significantly inhibits hepatocellular carcinoma growth.
abstract: OBJECTIVE
  Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Oncolytic viruses represent a promising therapeutic agent or vehicle to human cancers due to their ability of selectively lysing cancer cells but not in normal cells. TSLC1, a novel tumor suppressor gene, was loss in many human cancers including HCC, not in normal cells. The current study is focused on the antitumor effect of TSLC1-armed survivin-regulated oncolytic adenovirus for HCC and to explore their molecular mechanism.
  
  
  METHODS
  The expression of tumor suppressor TSLC1 and survivin was detected by quantitative PCR. The recombinant virus Ad.SP-E1A-E1B((Δ55))-TSLC1 (brief name as SD55-TSLC1) was constructed by inserting TSLC1 gene into the dual-regulated oncolytic adenovirus vector Ad.SP-E1A-E1B((Δ55)). Then, we performed the antitumor experiments of SD55-TSLC1 in vitro and in nude mice xenografted with Huh7 liver cancer.
  
  
  RESULTS
  The expression of TSLC1 was lower in HCC cells than in normal cells, which implied TSLC1 is a tumor suppressor of liver cancer. Survivin expression is higher in detected HCC cells than in normal cells. The SD55-TSLC1 exhibited an excellent antitumor effect on HCC cell growth in vitro but does no or little damage to normal liver cells. Animal experiment further confirmed that SD55-TSLC1 achieved significant inhibition of Huh7 liver cancer xenografted growth. Furthermore, the mechanism of antitumor efficacy by SD55-TSLC1 was elucidated to be due to the activation of caspase apoptotic pathway including the inducement of caspase-3, caspase-8, and poly (ADP-ribose) polymerase cleavage. This is the first report of TSLC1 by oncolytic adenovirus with an excellent antitumor effect to liver cancer growth.
  
  
  CONCLUSIONS
  These data suggest that an oncolytic adenovirus expressing TSLC1 is effective and support that SD55-TSLC1 may be a potent antitumoral agent for future clinical trials of liver cancer.
authors.affiliation: Xinyuan Institute of Medicine and Biotechnology, School of Life Sciences, Zhejiang Sci-Tech University, No. 2 Road Xiasha District, Hangzhou 310018, China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: He
authors.forename: Wen
authors.initials: W
authors.lastname: Lei
authors.forename: Shibin
authors.initials: S
authors.lastname: Wang
authors.forename: Ruijuan
authors.initials: R
authors.lastname: Xiao
authors.forename: Keni
authors.initials: K
authors.lastname: Guo
authors.forename: Yulong
authors.initials: Y
authors.lastname: Xia
authors.forename: Xiumei
authors.initials: X
authors.lastname: Zhou
authors.forename: Kangjian
authors.initials: K
authors.lastname: Zhang
authors.forename: Xinyuan
authors.initials: X
authors.lastname: Liu
authors.forename: Yigang
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000502:physiology; D017500:Adenovirus E1A Proteins / Q000235:genetics; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005822:Genetic Vectors / Q000235:genetics; D057809:HEK293 Cells; D054884:Host-Pathogen Interactions / Q000235:genetics; D006801:Humans; D007136:Immunoglobulins / Q000235:genetics* / Q000378:metabolism; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics* / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000235:genetics* / Q000628:therapy / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D046529:Microscopy, Electron, Transmission; D050130:Oncolytic Virotherapy / Q000379:methods; D050504:Oncolytic Viruses / Q000235:genetics* / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077022:Survivin; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics; D023041:Xenograft Model Antitumor Assays
chemical_list: D017500:Adenovirus E1A Proteins; C107489:BIRC5 protein, human; C403514:CADM1 protein, human; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules; C553319:E1B55K protein, adenovirus; D007136:Immunoglobulins; D051034:Inhibitor of Apoptosis Proteins; D000077022:Survivin; D025521:Tumor Suppressor Proteins; D014764:Viral Proteins; D020169:Caspases