Rho GTPase activity modulates Wnt3a/beta-catenin signaling

Cell Signal. 2009 Nov;21(11):1559-68. doi: 10.1016/j.cellsig.2009.05.010. Epub 2009 May 29.


Wnt proteins constitute a family of secreted signaling molecules that regulate highly conserved pathways essential for development and, when aberrantly activated, drive oncogenesis in a number of human cancers. A key feature of the most widely studied Wnt signaling cascade is the stabilization of cytosolic beta-catenin, resulting in beta-catenin nuclear translocation and transcriptional activation of multiple target genes. In addition to this canonical, beta-catenin-dependent pathway, Wnt3A has also been shown to stimulate RhoA GTPase. While the importance of activated Rho to non-canonical Wnt signaling is well appreciated, the potential contribution of Wnt3A-stimulated RhoA to canonical beta-catenin-dependent transcription has not been examined and is the focus of this study. We find that activated Rho is required for Wnt3A-stimulated osteoblastic differentiation in C3H10T1/2 mesenchymal stem cells, a biological phenomenon mediated by stabilized beta-catenin. Using expression microarrays and real-time RT-PCR analysis, we show that Wnt3A-stimulated transcription of a subset of target genes is Rho-dependent, indicating that full induction of these Wnt targets requires both beta-catenin and Rho activation. Significantly, neither beta-catenin stabilization nor nuclear translocation stimulated by Wnt3A is affected by inhibition or activation of RhoA. These findings identify Rho activation as a critical element of the canonical Wnt3A-stimulated, beta-catenin-dependent transcriptional program.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation
  • Cell Line
  • Humans
  • Mesenchymal Stem Cells / cytology
  • Mesenchymal Stem Cells / metabolism
  • Mice
  • Signal Transduction
  • Transcription, Genetic
  • Wnt Proteins / genetics
  • Wnt Proteins / metabolism*
  • Wnt3 Protein
  • Wnt3A Protein
  • beta Catenin / metabolism*
  • rhoA GTP-Binding Protein / metabolism*


  • WNT3A protein, human
  • Wnt Proteins
  • Wnt3 Protein
  • Wnt3A Protein
  • Wnt3a protein, mouse
  • beta Catenin
  • rhoA GTP-Binding Protein