title: Stable RNA nanoparticles as potential new generation drugs for cancer therapy.
abstract: Human genome sequencing revealed that only ~1.5% of the DNA sequence coded for proteins. More and more evidence has uncovered that a substantial part of the 98.5% so-called "junk" DNAs actually code for noncoding RNAs. Two milestones, chemical drugs and protein drugs, have already appeared in the history of drug development, and it is expected that the third milestone in drug development will be RNA drugs or drugs that target RNA. This review focuses on the development of RNA therapeutics for potential cancer treatment by applying RNA nanotechnology. A therapeutic RNA nanoparticle is unique in that its scaffold, ligand, and therapeutic component can all be composed of RNA. The special physicochemical properties lend to the delivery of siRNA, miRNA, ribozymes, or riboswitches; imaging using fluogenenic RNA; and targeting using RNA aptamers. With recent advances in solving the chemical, enzymatic, and thermodynamic stability issues, RNA nanoparticles have been found to be advantageous for in vivo applications due to their uniform nano-scale size, precise stoichiometry, polyvalent nature, low immunogenicity, low toxicity, and target specificity. In vivo animal studies have revealed that RNA nanoparticles can specifically target tumors with favorable pharmacokinetic and pharmacodynamic parameters without unwanted accumulation in normal organs. This review summarizes the key studies that have led to the detailed understanding of RNA nanoparticle formation as well as chemical and thermodynamic stability issue. The methods for RNA nanoparticle construction, and the current challenges in the clinical application of RNA nanotechnology, such as endosome trapping and production costs, are also discussed.
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA; Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Shu
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA; Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Fengmei
authors.initials: F
authors.lastname: Pi
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA; Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Ashwani
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA; Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Rajabi
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA; Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Farzin
authors.initials: F
authors.lastname: Haque
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA; Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Dan
authors.initials: D
authors.lastname: Shu
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA; Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: Markos
authors.initials: M
authors.lastname: Leggas
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA.
authors.forename: B Mark
authors.initials: BM
authors.lastname: Evers
authors.affiliation: Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA; Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY 40536, USA. Electronic address: peixuan.guo@uky.edu.
authors.forename: Peixuan
authors.initials: P
authors.lastname: Guo
mesh_terms: D000818:Animals; D016503:Drug Delivery Systems; D018014:Gene Transfer Techniques; D006801:Humans; D053758:Nanoparticles / Q000008:administration & dosage*; D009369:Neoplasms / Q000628:therapy*; D012313:RNA / Q000008:administration & dosage*
chemical_list: D012313:RNA
keywords: Bacteriophage phi29; Biodistribution of nanoparticles; Cancer targeting; Nanobiotechnology; Pharmacokinetics; RNA nanotechnology; RNA therapeutics; Three-way junction; pRNA