The Rho GTPase Rnd1 inhibits epithelial-mesenchymal transition in hepatocellular carcinoma and is a favorable anti-metastasis target

Cell Death Dis. 2018 May 1;9(5):486. doi: 10.1038/s41419-018-0517-x.

Abstract

Rnd1, a member of Rho GTPases, was found to be downregulated in human malignancies and downregulation of Rnd1 promotes tumor invasion via various mechanisms. However, the role of Rnd1 in hepatocellular carcinoma (HCC) progression remains unclear. In this study, our results demonstrated that Rnd1 was downregulated in HCC cells and in human HCC tissues. Low expression of Rnd1 was associated with aggressive clinic-pathologic characteristics, such as vascular invasion, and poor prognosis in patients who underwent curative surgery for HCC. Overexpression of Rnd1-suppressed cell growth, migration, invasion, and EMT processes in vitro and in vivo. Furthermore, Rnd1 blocked HCC progression by restricting EMT process through inhibition of the Raf/MEK/ERK cascade, and this was correlated with a reduction in RhoA activity. Combination of Rnd1 overexpression with sorafenib, a Raf signaling pathway inhibitor, showed a more potent inhibition on HCC metastasis. Moreover, epigenetic inhibitors (5-Aza and SAHA) increased the expression of Rnd1, and potentiated sorafenib-induced toxicity in HCC cells. In a conclusion, Rnd1-suppressed EMT-mediated metastasis of HCC by reducing the activity of the RhoA/Raf/MEK/ERK signaling pathway, functioning as a favorable anti-metastasis target for HCC patients. Rnd1 overexpression in combination with sorafenib may result in enhanced anti-metastasis efficacy in HCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinoma, Hepatocellular / drug therapy
  • Carcinoma, Hepatocellular / enzymology*
  • Carcinoma, Hepatocellular / genetics
  • Carcinoma, Hepatocellular / pathology
  • Cell Movement
  • Cell Proliferation
  • Decitabine / pharmacology
  • Epigenesis, Genetic
  • Epithelial-Mesenchymal Transition*
  • Female
  • Gene Expression Regulation, Enzymologic
  • Gene Expression Regulation, Neoplastic
  • Hep G2 Cells
  • Histone Deacetylase Inhibitors / pharmacology
  • Humans
  • Liver Neoplasms / drug therapy
  • Liver Neoplasms / enzymology*
  • Liver Neoplasms / genetics
  • Liver Neoplasms / pathology
  • Male
  • Mice, Inbred BALB C
  • Mice, Nude
  • Middle Aged
  • Molecular Targeted Therapy
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Protein Kinase Inhibitors / pharmacology
  • Signal Transduction
  • Sorafenib / pharmacology
  • Vorinostat / pharmacology
  • raf Kinases / antagonists & inhibitors
  • raf Kinases / metabolism
  • rho GTP-Binding Proteins / genetics
  • rho GTP-Binding Proteins / metabolism*
  • rhoA GTP-Binding Protein / metabolism

Substances

  • Histone Deacetylase Inhibitors
  • Protein Kinase Inhibitors
  • RND1 protein, human
  • RHOA protein, human
  • Vorinostat
  • Decitabine
  • Sorafenib
  • raf Kinases
  • rho GTP-Binding Proteins
  • rhoA GTP-Binding Protein