title: Vectors and strategies for nonviral cancer gene therapy.
abstract: BACKGROUND
  This review presents recent developments in the use of nonviral vectors and transfer technologies in cancer gene therapy. Tremendous progress has been made in developing cancer gene therapy in ways that could be applicable to treatments. Numerous efforts are focused on methods of attacking known and novel targets more efficiently and specifically. In parallel to progress in nonviral vector design and delivery technologies, important achievements have been accomplished for suicide, gene replacement, gene suppression and immunostimulatory therapies. New nonviral cancer gene therapies have been developed based on emerging RNAi (si/shRNA-, miRNA) or ODN.
  
  
  METHODS
  This review provides an overview of recent gene therapeutic strategies in which nonviral vectors have been used experimentally and in clinical trials. Furthermore, we present current developments in nonviral vector systems in association with important chemical and physical gene delivery technologies and their potential for the future.
  
  
  CONCLUSIONS
  Nonviral gene therapy has maintained its position as an approach for treating cancer. This is reflected by the fact that more than 17% of all gene therapy trials employ nonviral approaches. Thus, nonviral vectors have emerged as a clinical alternative to viral vectors for the appropriate expression and delivery of therapeutic genes.
authors.affiliation: a Experimental and Clinical Research Center , Charité University Medicine Berlin and Max-Delbrück-Center for Moelcular Medicine , Berlin , Germany.
authors.forename: Jessica
authors.initials: J
authors.lastname: Pahle
authors.affiliation: a Experimental and Clinical Research Center , Charité University Medicine Berlin and Max-Delbrück-Center for Moelcular Medicine , Berlin , Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Walther
mesh_terms: D018014:Gene Transfer Techniques; D052138:Genes, Neoplasm / Q000235:genetics; D015316:Genetic Therapy / Q000379:methods* / Q000639:trends; D005822:Genetic Vectors; D006801:Humans; D035683:MicroRNAs / Q000235:genetics; D009369:Neoplasms / Q000628:therapy*
chemical_list: D035683:MicroRNAs
keywords: Cancer; Gene therapy; gene transfer; nonviral vectors