title: Targeting hepatoma using nitric oxide donor strategies.
abstract: OBJECTIVE
  The study evaluated the role of increased intracellular nitric oxide (NO) concentration using NO donors or stably NO synthase-3 (NOS-3) overexpression during CD95-dependent cell death in hepatoma cells. The expression of cell death receptors and caspase activation, RhoA kinase activity, NOS-3 expression/activity, oxidative/nitrosative stress, and p53 expression were analyzed. The antitumoral activity of NO was also evaluated in the subcutaneous implantation of NOS-3-overexpressing hepatoma cells, as well NO donor injection into wild-type hepatoma-derived tumors implanted in xenograft mouse models.
  
  
  RESULTS
  NO donor increased CD95 expression and activation of caspase-8 and 3 in HepG2, Huh7, and Hep3B cells. NOS-3 overexpression increased oxidative/nitrosative stress, p53 and CD95 expression, cellular Fas-associated death domain (FADD)-like IL-1beta converting enzyme (FLICE) inhibitory protein long (cFLIP(L)) and its short isoform (cFLIP(S)) shift, and cell death in HepG2 (4TO-NOS) cells. The inhibition of RhoA kinase and p53 knockdown using RNA interference reduced cell death in 4TO-NOS cells. The supplementation with hydrogen peroxide (H(2)O(2)) increased NOS-3 activity and cell death in 4TO-NOS cells. NOS-3 overexpression or NO donor injection into hepatoma-derived tumors reduced the size and increased p53 and cell death receptor expression in nude mice.
  
  
  CONCLUSIONS
  The increase of intracellular NO concentration promoted oxidative and nitrosative stress, Rho kinase activity, p53 and CD95 expression, and cell death in cultured hepatoma cells. NOS-3-overexpressed HepG2 cells or intratumoral NO donor administration reduced tumor cell growth and increased the expression of p53 and cell death receptors in tumors developed in a xenograft mouse model.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Córdoba, Córdoba, Spain.
authors.forename: Raúl
authors.initials: R
authors.lastname: González
authors.forename: Gustavo
authors.initials: G
authors.lastname: Ferrín
authors.forename: Patricia
authors.initials: P
authors.lastname: Aguilar-Melero
authors.forename: Isidora
authors.initials: I
authors.lastname: Ranchal
authors.forename: Clara I
authors.initials: CI
authors.lastname: Linares
authors.forename: Rosario I
authors.initials: RI
authors.lastname: Bello
authors.forename: Manuel
authors.initials: M
authors.lastname: De la Mata
authors.forename: Vladimir
authors.initials: V
authors.lastname: Gogvadze
authors.forename: José A
authors.initials: JA
authors.lastname: Bárcena
authors.forename: José M
authors.initials: JM
authors.lastname: Alamo
authors.forename: Sten
authors.initials: S
authors.lastname: Orrenius
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Padillo
authors.forename: Boris
authors.initials: B
authors.lastname: Zhivotovsky
authors.forename: Jordi
authors.initials: J
authors.lastname: Muntané
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D016158:Genes, p53; D006801:Humans; D008113:Liver Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays; D019014:fas Receptor / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D020030:Nitric Oxide Donors; D019014:fas Receptor; C066737:RHOA protein, human; D020742:rhoA GTP-Binding Protein