title: Human Sulfatase-1 Improves the Effectiveness of Cytosine Deaminase Suicide Gene Therapy with 5-Fluorocytosine Treatment on Hepatocellular Carcinoma Cell Line HepG2 In Vitro and In Vivo.
abstract: BACKGROUND
  Human sulfatase-1 (Hsulf-1) is an endosulfatase that selectively removes sulfate groups from heparan sulfate proteoglycans (HSPGs), altering the binding of several growth factors and cytokines to HSPG to regulate cell proliferation, cell motility, and apoptosis. We investigated the role of combined cancer gene therapy with Hsulf-1 and cytosine deaminase/5-fluorocytosine (CD/5-FC) suicide gene on a hepatocellular carcinoma (HCC) cell line, HepG2, in vitro and in vivo.
  
  
  METHODS
  Reverse transcription polymerase chain reaction and immunohistochemistry were used to determine the expression of Hsulf-1 in HCC. Cell apoptosis was observed through flow cytometry instrument and mechanism of Hsulf-1 to enhance the cytotoxicity of 5-FC against HCC was analyzed in HCC by confocal microscopy. We also establish a nude mice model of HCC to address the effect of Hsulf-1 expression on the CD/5-FC suicide gene therapy in vivo.
  
  
  RESULTS
  A significant decrease in HepG2 cell proliferation and an increase in HepG2 cell apoptosis were observed when Hsulf-1 expression was combined with the CD/5-FC gene suicide system. A noticeable bystander effect was observed when the Hsulf-1 and CD genes were co-expressed. Intracellular calcium was also increased after HepG2 cells were infected with the Hsulf-1 gene. In vivo studies showed that the suppression of tumor growth was more pronounced in animals treated with the Hsulf-1 plus CD than those treated with either gene therapy alone, and the combined treatment resulted in a significant increase in survival.
  
  
  CONCLUSIONS
  Hsulf-1 expression combined with the CD/5-FC gene suicide system could be an effective treatment approach for HCC.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Yang
authors.forename: Ling
authors.initials: L
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of General Surgery, Hangzhou First People's Hospital, Hangzhou Hospital Affiliated to Nanjing Medical University, Hangzhou, Zhejiang 310006, China.
authors.forename: Sheng-Lin
authors.initials: SL
authors.lastname: Ma
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D006528:Carcinoma, Hepatocellular / Q000201:enzymology* / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects / Q000235:genetics; D043525:Cytosine Deaminase / Q000235:genetics / Q000378:metabolism*; D005437:Flucytosine / Q000494:pharmacology*; D015316:Genetic Therapy; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000201:enzymology / Q000378:metabolism; D013429:Sulfatases / Q000235:genetics / Q000378:metabolism*
chemical_list: D005437:Flucytosine; D013429:Sulfatases; D043525:Cytosine Deaminase