title: HER2/ErbB2-induced breast cancer cell migration and invasion require p120 catenin activation of Rac1 and Cdc42.
abstract: Breast cancers that overexpress the receptor tyrosine kinase ErbB2/HER2/Neu result in poor patient outcome because of extensive metastatic progression. Herein, we delineate a molecular mechanism that may govern this malignant phenotype. ErbB2 induction of migration requires activation of the small GTPases Rac1 and Cdc42. The ability of ErbB2 to activate these small GTPases necessitated expression of p120 catenin, which is itself up-regulated by signaling through ErbB2 and the tyrosine kinase Src. Silencing p120 in ErbB2-dependent breast cancer cell lines dramatically inhibited migration and invasion as well as activation of Rac1 and Cdc42. In contrast, overexpression of constitutively active mutants of these GTPases reversed the effects of p120 silencing. Lastly, ectopic expression of p120 promoted migration and invasion and potentiated metastatic progression of a weakly metastatic, ErbB2-dependent breast cancer cell line. These results suggest that p120 acts as an obligate intermediate between ErbB2 and Rac1/Cdc42 to modulate the metastatic potential of breast cancer cells.
authors.affiliation: Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.
authors.forename: Emhonta
authors.initials: E
authors.lastname: Johnson
authors.forename: Darcie D
authors.initials: DD
authors.lastname: Seachrist
authors.forename: Carlos M
authors.initials: CM
authors.lastname: DeLeon-Rodriguez
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Lozada
authors.forename: John
authors.initials: J
authors.lastname: Miedler
authors.forename: Fadi W
authors.initials: FW
authors.lastname: Abdul-Karim
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Keri
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D051177:Catenins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D051379:Mice; D008819:Mice, Nude; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D014945:Wound Healing / Q000235:genetics / Q000502:physiology; D020764:cdc42 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*; D000095002:Delta Catenin
chemical_list: D051177:Catenins; D018719:Erb-b2 Receptor Tyrosine Kinases; D020764:cdc42 GTP-Binding Protein; D020830:rac1 GTP-Binding Protein; D000095002:Delta Catenin