title: Role of c-Src in human MCF7 breast cancer cell tumorigenesis.
abstract: To study the role of c-Src in breast cancer tumorigenesis, we generated a cell line derived from MCF7 carrying an inducible dominant negative c-Src (c-SrcDN: K295M/Y527F) under tetracycline control (Tet-On system). c-SrcDN expression caused phenotypic changes, relocation of c-Src, Fak, and paxillin, and loss of correct actin fiber assembly. These alterations were coupled to increased Fak-Tyr(397) autophosphorylation and to inhibition of Fak-Tyr(925), p130(CAS), and paxillin phosphorylation. An increased association of total Src with Fak and a decreased interaction of p130(CAS) and p85-PI3K with Fak were also observed. SrcDN inhibited cell attachment, spreading, and migration. Serum and EGF-induced stimulation of cell proliferation and Akt phosphorylation were also significantly reduced by SrcDN, whereas p27(Kip1) expression was increased. Consistently, silencing c-Src expression by siRNA in MCF7 cells significantly reduced cell migration, attachment, spreading and proliferation. Inoculation of MCF7 cells carrying inducible SrcDN to nude mice generated tumors. However, doxycycline administration to mice significantly reduced tumorigenesis, and when doxycycline treatment was installed after tumor development, a significant tumor regression was observed. In both situations, inhibition of tumorigenesis was associated with decreased Ki67 staining and increased apoptosis in tumors. These data undoubtedly demonstrate the relevance of the Src/Fak complex in breast cancer tumorigenesis.
authors.affiliation: Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: González
authors.affiliation: Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Agulló-Ortuño
authors.affiliation: Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: García-Martínez
authors.affiliation: Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy.
authors.forename: Annarica
authors.initials: A
authors.lastname: Calcabrini
authors.affiliation: Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Gamallo
authors.affiliation: Centro Nacional de Investigaciones Oncológicas, Melchor Fernández Almagro 3, 28029 Madrid, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Palacios
authors.affiliation: Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Aranda
authors.affiliation: Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain. Electronic address: jmartin@iib.uam.es.
authors.forename: Jorge
authors.initials: J
authors.lastname: Martín-Pérez
mesh_terms: D000818:Animals; D000081247:CSK Tyrosine-Protein Kinase; D045744:Cell Line, Tumor; D050719:Crk-Associated Substrate Protein / Q000378:metabolism; D005260:Female; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D005799:Genes, Dominant; D006801:Humans; D019394:Ki-67 Antigen / Q000096:biosynthesis; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D019061:src-Family Kinases
chemical_list: D000081247:CSK Tyrosine-Protein Kinase; D050719:Crk-Associated Substrate Protein; D051417:Focal Adhesion Kinase 1; D019394:Ki-67 Antigen; D019869:Phosphatidylinositol 3-Kinases; D011505:Protein-Tyrosine Kinases; D019061:src-Family Kinases; C496050:PTK2 protein, human; C000631346:CSK protein, human