title: RNAi-nanoparticulate manipulation of gene expression as a new functional genomics tool in the liver.
abstract: OBJECTIVE
  The Hippo pathway controls organ size through a negative regulation of the transcription co-activator Yap1. The overexpression of hyperactive mutant Yap1 or deletion of key components in the Hippo pathway leads to increased organ size in different species. Analysis of interactions of this pathway with other cellular signals corroborating organ size control is limited in part due to the difficulties associated with development of rodent models.
  
  
  METHODS
  Here, we develop a new model of reversible induction of the liver size in mice using siRNA-nanoparticles targeting two kinases of the Hippo pathway, namely, mammalian Ste20 family kinases 1 and 2 (Mst1 and Mst2), and an upstream regulator, neurofibromatosis type II (Nf2).
  
  
  RESULTS
  The triple siRNAs nanoparticle-induced hepatomegaly in mice phenocopies one observed with Mst1(-/-)Mst2(-/-) liver-specific depletion, as shown by extensive proliferation of hepatocytes and activation of Yap1. The simultaneous co-treatment with a fourth siRNA nanoparticle against Yap1 fully blocked the liver growth. Hippo pathway-induced liver enlargement is associated with p53 activation, evidenced by its accumulation in the nuclei and upregulation of its target genes. Moreover, injections of the triple siRNAs nanoparticle in p53(LSL/LSL) mice shows that livers lacking p53 expression grow faster and exceed the size of livers in p53 wild-type animals, indicating a role of p53 in controlling Yap1-induced liver growth.
  
  
  CONCLUSIONS
  Our data show that siRNA-nanoparticulate manipulation of gene expression can provide the reversible control of organ size in adult animals, which presents a new avenue for the investigation of complex regulatory networks in liver.
authors.affiliation: David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Yin
authors.affiliation: David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Roman L
authors.initials: RL
authors.lastname: Bogorad
authors.affiliation: Alnylam Pharmaceuticals, Cambridge, MA 02142, USA.
authors.forename: Carmen
authors.initials: C
authors.lastname: Barnes
authors.affiliation: David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Walsh
authors.affiliation: David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Iris
authors.initials: I
authors.lastname: Zhuang
authors.affiliation: Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Dresden 01307, Germany.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Nonaka
authors.affiliation: David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Vera
authors.initials: V
authors.lastname: Ruda
authors.affiliation: Alnylam Pharmaceuticals, Cambridge, MA 02142, USA.
authors.forename: Satya
authors.initials: S
authors.lastname: Kuchimanchi
authors.affiliation: Alnylam Pharmaceuticals, Cambridge, MA 02142, USA.
authors.forename: Lubomir
authors.initials: L
authors.lastname: Nechev
authors.affiliation: Alnylam Pharmaceuticals, Cambridge, MA 02142, USA.
authors.forename: Akin
authors.initials: A
authors.lastname: Akinc
authors.affiliation: RNA Therapeutics Institute and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.
authors.forename: Wen
authors.initials: W
authors.lastname: Xue
authors.affiliation: Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Dresden 01307, Germany.
authors.forename: Marino
authors.initials: M
authors.lastname: Zerial
authors.affiliation: David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Harvard-MIT Division of Health Sciences & Technology, Cambridge, MA 02139, USA; Institute of Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Langer
authors.affiliation: David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Harvard-MIT Division of Health Sciences & Technology, Cambridge, MA 02139, USA; Institute of Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Electronic address: dgander@mit.edu.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Anderson
authors.affiliation: Skolkovo Institute of Science and Technology, Skolkovo 143025, Russia; Department of Chemistry, M.V. Lomonosov Moscow State University, Leninskie Gory 119991, Russia. Electronic address: V.Kotelianski@Skoltech.RU.
authors.forename: Victor
authors.initials: V
authors.lastname: Koteliansky
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000502:physiology; D000818:Animals; D018797:Cell Cycle Proteins; D015870:Gene Expression; D016515:Genes, Neurofibromatosis 2; D023281:Genomics / Q000379:methods*; D017228:Hepatocyte Growth Factor / Q000235:genetics; D006529:Hepatomegaly / Q000209:etiology; D008099:Liver / Q000254:growth & development* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D053758:Nanoparticles; D009929:Organ Size; D010750:Phosphoproteins / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics; D034622:RNA Interference; D000090742:Serine-Threonine Kinase 3; D016159:Tumor Suppressor Protein p53 / Q000502:physiology; D000091102:YAP-Signaling Proteins; D000099317:Hippo Kinases
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; D017228:Hepatocyte Growth Factor; D010750:Phosphoproteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D000090742:Serine-Threonine Kinase 3; D016159:Tumor Suppressor Protein p53; D000091102:YAP-Signaling Proteins; C486223:Yap1 protein, mouse; C082332:macrophage stimulating protein; C490818:Stk3 protein, mouse; D000099317:Hippo Kinases
keywords: Bile acids; Hippo pathway; Nanoparticles; p53; siRNA