title: Targeting β-catenin in hepatocellular cancers induced by coexpression of mutant β-catenin and K-Ras in mice.
abstract: Recently, we have shown that coexpression of hMet and mutant-β-catenin using sleeping beauty transposon/transposase leads to hepatocellular carcinoma (HCC) in mice that corresponds to around 10% of human HCC. In the current study, we investigate whether Ras activation, which can occur downstream of Met signaling, is sufficient to cause HCC in association with mutant-β-catenin. We also tested therapeutic efficacy of targeting β-catenin in an HCC model. We show that mutant-K-Ras (G12D), which leads to Ras activation, cooperates with β-catenin mutants (S33Y, S45Y) to yield HCC in mice. Affymetrix microarray showed > 90% similarity in gene expression in mutant-K-Ras-β-catenin and Met-β-catenin HCC. K-Ras-β-catenin tumors showed up-regulation of β-catenin targets like glutamine synthetase (GS), leukocyte cell-derived chemotaxin 2, Regucalcin, and Cyclin-D1 and of K-Ras effectors, including phosphorylated extracellular signal-regulated kinase, phosphorylated protein kinase B, phosphorylated mammalian target of rapamycin, phosphorylated eukaryotic translation initiation factor 4E, phosphorylated 4E-binding protein 1, and p-S6 ribosomal protein. Inclusion of dominant-negative transcription factor 4 at the time of K-Ras-β-catenin injection prevented HCC and downstream β-catenin and Ras signaling. To address whether targeting β-catenin has any benefit postestablishment of HCC, we administered K-Ras-β-catenin mice with EnCore lipid nanoparticles (LNP) loaded with a Dicer substrate small interfering RNA targeting catenin beta 1 (CTNNB1; CTNNB1-LNP), scrambled sequence (Scr-LNP), or phosphate-buffered saline for multiple cycles. A significant decrease in tumor burden was evident in the CTNNB1-LNP group versus all controls, which was associated with dramatic decreases in β-catenin targets and some K-Ras effectors, leading to reduced tumor cell proliferation and viability. Intriguingly, in relatively few mice, non-GS-positive tumors, which were evident as a small subset of overall tumor burden, were not affected by β-catenin suppression.
  
  
  
  Ras activation downstream of c-Met is sufficient to induce clinically relevant HCC in cooperation with mutant β-catenin. β-catenin suppression by a clinically relevant modality is effective in treatment of β-catenin-positive, GS-positive HCCs. (Hepatology 2017;65:1581-1599).
authors.affiliation: Department of Pathology, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.|Pittsburgh Liver Research Center, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.
authors.forename: Junyan
authors.initials: J
authors.lastname: Tao
authors.affiliation: Department of Pathology, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.|Pittsburgh Liver Research Center, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Pathology, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.|Pittsburgh Liver Research Center, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.
authors.forename: Sucha
authors.initials: S
authors.lastname: Singh
authors.affiliation: Department of Pathology, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.|Pittsburgh Liver Research Center, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.
authors.forename: Minakshi
authors.initials: M
authors.lastname: Poddar
authors.affiliation: Raleigh Charter High School, Raleigh, NC.
authors.forename: Emily
authors.initials: E
authors.lastname: Xu
authors.affiliation: Department of Pathology, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.|Pittsburgh Liver Research Center, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.
authors.forename: Michael
authors.initials: M
authors.lastname: Oertel
authors.affiliation: Department of Bioengineering and Therapeutic Sciences, University California, San Francisco, CA.|Liver Center, University California, San Francisco, CA.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.affiliation: Dicerna Pharmaceuticals, Inc, Cambridge, MA.
authors.forename: Shanthi
authors.initials: S
authors.lastname: Ganesh
authors.affiliation: Dicerna Pharmaceuticals, Inc, Cambridge, MA.
authors.forename: Marc
authors.initials: M
authors.lastname: Abrams
authors.affiliation: Department of Pathology, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.|Pittsburgh Liver Research Center, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.|Department of Medicine, University of Pittsburgh, School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA.
authors.forename: Satdarshan P
authors.initials: SP
authors.lastname: Monga
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000209:etiology* / Q000378:metabolism; D011905:Genes, ras; D008114:Liver Neoplasms, Experimental / Q000209:etiology* / Q000378:metabolism; D020935:MAP Kinase Signaling System; D008297:Male; D051379:Mice; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D051176:beta Catenin / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D051176:beta Catenin; C546843:mTOR protein, mouse; D058570:TOR Serine-Threonine Kinases