title: Downregulation of tumor growth and invasion by redox-active nanoparticles.
abstract: OBJECTIVE
  Melanoma is the most aggressive type of malignant skin cancer derived from uncontrolled proliferation of melanocytes. Melanoma cells possess a high potential to metastasize, and the prognosis for advanced melanoma is rather poor due to its strong resistance to conventional chemotherapeutics. Nanomaterials are at the cutting edge of the rapidly developing area of nanomedicine. The potential of nanoparticles for use as carrier in cancer drug delivery is infinite with novel applications constantly being tested. The noncarrier use of cerium oxide nanoparticles (CNPs) is a novel and promising approach, as those particles per se show an anticancer activity via their oxygen vacancy-mediated chemical reactivity.
  
  
  RESULTS
  In this study, the question was addressed of whether the use of CNPs might be a valuable tool to counteract the invasive capacity and metastasis of melanoma cells in the future. Therefore, the effect of those nanoparticles on human melanoma cells was investigated in vitro and in vivo. Concentrations of polymer-coated CNPs being nontoxic for stromal cells showed a cytotoxic, proapoptotic, and anti-invasive capacity on melanoma cells. In vivo xenograft studies with immunodeficient nude mice showed a decrease of tumor weight and volume after treatment with CNPs.
  
  
  METHODS
  In summary, the redox-active CNPs have selective pro-oxidative and antioxidative properties, and this study is the first to show that CNPs prevent tumor growth in vivo.
  
  
  CONCLUSIONS
  The application of redox-active CNPs may form the basis of new paradigms in the treatment and prevention of cancers.
authors.affiliation: Medical Faculty, Institute of Biochemistry & Molecular Biology I, Heinrich-Heine-University, 40225 Duesseldorf, Germany. lirija.alili@web.de
authors.forename: Lirija
authors.initials: L
authors.lastname: Alili
authors.forename: Maren
authors.initials: M
authors.lastname: Sack
authors.forename: Claudia
authors.initials: C
authors.lastname: von Montfort
authors.forename: Shailendra
authors.initials: S
authors.lastname: Giri
authors.forename: Soumen
authors.initials: S
authors.lastname: Das
authors.forename: Kate S
authors.initials: KS
authors.lastname: Carroll
authors.forename: Klaus
authors.initials: K
authors.lastname: Zanger
authors.forename: Sudipta
authors.initials: S
authors.lastname: Seal
authors.forename: Peter
authors.initials: P
authors.lastname: Brenneisen
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D051242:Caveolin 1 / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002563:Cerium / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D015536:Down-Regulation; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008545:Melanoma / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles / Q000737:chemistry*; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic / Q000188:drug therapy; D010084:Oxidation-Reduction; D050050:Protein Carbonylation; D017382:Reactive Oxygen Species / Q000378:metabolism; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000473:pathology; D047368:Tumor Burden / Q000187:drug effects*; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D051242:Caveolin 1; D017382:Reactive Oxygen Species; D002563:Cerium; C030583:ceric oxide