Inactivation of Rho GTPases by p190 RhoGAP reduces human pancreatic cancer cell invasion and metastasis.

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.

• Authors: Toshiyuki Kusama, Mutsuko Mukai, Hiroko Endo, Osamu Ishikawa, Masaharu Tatsuta, Hiroyuki Nakamura, Masahiro Inoue
• Journal: Cancer science (Cancer Sci) Vol. 97 Issue 9 Pg. 848-53 (Sep 2006) ISSN: 1347-9032 [Print] England
• PMID: 16776779 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 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

Topics

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