Inactivation of Rho GTPases by p190 RhoGAP Reduces Human Pancreatic Cancer Cell Invasion and Metastasis

Cancer Sci. 2006 Sep;97(9):848-53. doi: 10.1111/j.1349-7006.2006.00242.x. Epub 2006 Jun 14.

Abstract

A number of small GTPases are involved in cancer cell proliferation, migration and invasion, acting as molecular switches that cycle between GTP- and GDP-bound states. GTPase-activating proteins (GAPs) have been established as a major class of negative regulators of Rho GTPase signaling. To investigate the biological function of p190 RhoGAP toward RhoA in cancer cell invasion and metastasis, we generated a chimera made of the RhoGAP domain of p190 and the C-terminus of RhoA (p190-RhoA chimera), and transfected it into human pancreatic cancer cells, AsPC-1. Epidermal growth factor (EGF)-induced activation of RhoA, as well as RhoB and RhoC, to a lesser extent, was significantly inhibited in p190-RhoA chimera-transfected AsPC-1 cells compared with that of control cells (mock-infected), when assessed by pull-down assay for GTP-bound RhoA, RhoB, and RhoC, respectively. EGF-induced invasion of p190-RhoA chimera transfectants was significantly inhibited compared with that of mock-infected cells in a modified Boyden chamber assay. Furthermore, the mice injected intrasplenically with AsPC-1 cells that overexpressed the p190-RhoA chimera had a marked reduction in the number and size of metastatic nodules in the liver. These data suggest that the inhibitory action of p190 RhoGAP toward RhoA offers a novel approach to the treatment of invasion and metastasis of cancer cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Line, Tumor
  • Chimera
  • DNA-Binding Proteins
  • Enzyme Activation / drug effects
  • Enzyme Activation / physiology
  • Epidermal Growth Factor / pharmacology
  • GTPase-Activating Proteins
  • Guanine Nucleotide Exchange Factors
  • Humans
  • Mice
  • Mitogen-Activated Protein Kinases / drug effects
  • Mitogen-Activated Protein Kinases / metabolism
  • Neoplasm Invasiveness / physiopathology*
  • Neoplasm Transplantation
  • Neoplasms, Experimental / pathology
  • Pancreatic Neoplasms / enzymology
  • Pancreatic Neoplasms / pathology*
  • Repressor Proteins
  • Transfection
  • rho GTP-Binding Proteins / drug effects
  • rho GTP-Binding Proteins / genetics
  • rho GTP-Binding Proteins / metabolism*

Substances

  • ARHGAP35 protein, human
  • ARHGAP5 protein, human
  • Arhgap35 protein, mouse
  • Arhgap5 protein, mouse
  • Carrier Proteins
  • DNA-Binding Proteins
  • GTPase-Activating Proteins
  • Guanine Nucleotide Exchange Factors
  • Repressor Proteins
  • Epidermal Growth Factor
  • Mitogen-Activated Protein Kinases
  • rho GTP-Binding Proteins