Role of c-Src in human MCF7 breast cancer cell tumorigenesis.
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.
González
Lorena
L
Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain.
Agulló-Ortuño
María Teresa
MT
Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain.
García-Martínez
José Manuel
JM
Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain.
Calcabrini
Annarica
A
Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy.
Gamallo
Carlos
C
Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain.
Palacios
José
J
Centro Nacional de Investigaciones Oncológicas, Melchor Fernández Almagro 3, 28029 Madrid, Spain.
Aranda
Ana
A
Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain.
Martín-Pérez
Jorge
J
Instituto de Investigaciones Biomédicas Alberto Sols (CSIC/UAM), Arturo Duperier 4, 28029 Madrid, Spain. Electronic address: jmartin@iib.uam.es.
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
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