title: 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.affiliation: Department of Biochemistry, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kusama
authors.forename: Mutsuko
authors.initials: M
authors.lastname: Mukai
authors.forename: Hiroko
authors.initials: H
authors.lastname: Endo
authors.forename: Osamu
authors.initials: O
authors.lastname: Ishikawa
authors.forename: Masaharu
authors.initials: M
authors.lastname: Tatsuta
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Inoue
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002678:Chimera; D004268:DNA-Binding Proteins; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors; D006801:Humans; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000201:enzymology / Q000473:pathology*; D012097:Repressor Proteins; D014162:Transfection; D020741:rho GTP-Binding Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
chemical_list: C074560:ARHGAP35 protein, human; C513043:ARHGAP5 protein, human; C513041:Arhgap35 protein, mouse; C513042:Arhgap5 protein, mouse; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors; D012097:Repressor Proteins; D004815:Epidermal Growth Factor; D020928:Mitogen-Activated Protein Kinases; D020741:rho GTP-Binding Proteins