title: p120 catenin induces opposing effects on tumor cell growth depending on E-cadherin expression.
abstract: p120 catenin regulates the activity of the Rho family guanosine triphosphatases (including RhoA and Rac1) in an adhesion-dependent manner. Through this action, p120 promotes a sessile cellular phenotype when associated with epithelial cadherin (E-cadherin) or a motile phenotype when associated with mesenchymal cadherins. In this study, we show that p120 also exerts significant and diametrically opposing effects on tumor cell growth depending on E-cadherin expression. Endogenous p120 acts to stabilize E-cadherin complexes and to actively promote the tumor-suppressive function of E-cadherin, potently inhibiting Ras activation. Upon E-cadherin loss during tumor progression, the negative regulation of Ras is relieved; under these conditions, endogenous p120 promotes transformed cell growth both in vitro and in vivo by activating a Rac1-mitogen-activated protein kinase signaling pathway normally activated by the adhesion of cells to the extracellular matrix. These data indicate that both E-cadherin and p120 are important regulators of tumor cell growth and imply roles for both proteins in chemoresistance and targeted therapeutics.
authors.affiliation: Mayo Clinic Comprehensive Cancer Center, Mayo Clinic, Jacksonville, FL 32224, USA.
authors.forename: Edwin
authors.initials: E
authors.lastname: Soto
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yanagisawa
authors.forename: Laura A
authors.initials: LA
authors.lastname: Marlow
authors.forename: John A
authors.initials: JA
authors.lastname: Copland
authors.forename: Edith A
authors.initials: EA
authors.lastname: Perez
authors.forename: Panos Z
authors.initials: PZ
authors.lastname: Anastasiadis
mesh_terms: D000818:Animals; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D051177:Catenins; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D051379:Mice; D008819:Mice, Nude; D009374:Neoplasms, Experimental / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D000075370:Receptors for Activated C Kinase; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D020742:rhoA GTP-Binding Protein; D000095002:Delta Catenin
chemical_list: D015820:Cadherins; D051177:Catenins; D015815:Cell Adhesion Molecules; D009479:Neuropeptides; D010750:Phosphoproteins; C090294:RACK1 protein, mouse; D000075370:Receptors for Activated C Kinase; C526380:RhoA protein, mouse; D018631:ras Proteins; D020741:rho GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein; D000095002:Delta Catenin; C000722349:Ctnnd1 protein, mouse