title: [Insulin-like growth factor receptor I signaling in a breast cancer cell line].
abstract: BACKGROUND
  In vitro studies strongly suggest that proliferation, migration and cell survival of breast cancer cell lines are significantly affected by activation of the IGF type 1 receptor (IGF-IR).
  
  
  OBJECTIVE
  The phosphorylation by IGF-I of IGF-IR and the intracellular signaling molecules Akt (PI-3K pathway) and Erk1/2 (MAPK pathway) was characterized in a human breast cancer cell lines.
  
  
  METHODS
  The study compared a standard breast adenocarcinoma line (MCF-7) cell line with a line (CSC 1595) derived from an infiltrating ductal breast cancer in a Colombian patient. The CSC 1595 and MCF-7 cell lines were cultured in DMEM supplemented with 10% fetal bovine serum, 2 mM glutamine, 100 U/ml penicillin, and 100 µg/ml streptomycin and grown at 37 °C in 5% CO₂ atmosphere and 95% humidity. Cell extracts were prepared, followed by immunoprecipitation and immunoblotting with specific anti-pIGF-IR, anti-pERK1/2 and anti-pAkt antibodies.
  
  
  RESULTS
  After 5 minute stimulation with IGF-I, 70% of the IGF-IR was phosphorylated in the cell line CSC 1595 and 25% in MCF-7. In addition, Akt (oncogene protein v-akt) and ERK1/2 (extracellular signal-regulated MAP kinases) were phosphorylated. Basal and stimulated levels of phosphorylated ERK1/2 were substantially higher compared to those in the MCF-7 cell line.
  
  
  CONCLUSIONS
  The IGF-IR and MAPK kinase pathway involving proteins ERK1/2 showed more significant phosphorylation in the 1,595 cells compared to the observed in the MCF-7 cell line. Since the IGF-IR is the major activator of this pathway it may play an important role in ductal infiltrating breast cancer tumor growth and metastases.
authors.affiliation: Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, D.C, Colombia. wmejia@javeriana.edu.co
authors.forename: Wilson
authors.initials: W
authors.lastname: Mejía
authors.forename: Carlos
authors.initials: C
authors.lastname: Castro
authors.forename: Adriana
authors.initials: A
authors.lastname: Umaña
authors.forename: Clemencia
authors.initials: C
authors.lastname: de Castro
authors.forename: Tulia
authors.initials: T
authors.lastname: Riveros
authors.forename: Myriam
authors.initials: M
authors.lastname: Sánchez-Gómez
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000503:physiopathology*; D045744:Cell Line, Tumor; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005260:Female; D006801:Humans; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D019869:Phosphatidylinositol 3-Kinases; D017526:Receptor, IGF Type 1; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases