title: Raf-1 activation in gastrointestinal carcinoid cells decreases tumor cell adhesion.
abstract: BACKGROUND
  Gastrointestinal carcinoid tumors are highly metastatic. Activation of the Raf-1 signaling pathway in carcinoid cells results in morphologic changes. These Raf-1-induced structural changes may affect cellular adhesion, thereby altering metastatic potential.
  
  
  METHODS
  An estrogen-inducible Raf-1 cell line (BON-raf) was used to study the effects of Raf-1 on cellular adhesion. Cell adhesion was measured before and after Raf-1 induction. Western blot analysis was used to confirm Raf-1 activation and measure levels of an essential adhesion regulator, beta-catenin.
  
  
  RESULTS
  Estrogen treatment of BON-raf cells resulted in Raf-1 activation and a marked decrease (68%) in cell adhesion. In the absence of Raf-1 induction, carcinoid cells expressed high levels of beta-catenin. Raf-1 activation led to decreased expression of beta-catenin.
  
  
  CONCLUSIONS
  Raf-1 induction in carcinoid cells results in a significant decrease in adhesion. Furthermore, the important adhesion regulator, beta-catenin, is decreased in activated BON-raf cells. These Raf-1-related changes in adhesion may alter the metastatic phenotype of carcinoid cells.
authors.affiliation: Endocrine Surgery Research Laboratories, Section of Endocrine Surgery, Department of Surgery, University of Wisconsin, H4/750 Clinical Science Center, 600 Highland Ave., Madison, WI 53792, USA.
authors.forename: David Yü
authors.initials: DY
authors.lastname: Greenblatt
authors.forename: Muthusamy
authors.initials: M
authors.lastname: Kunnimalaiyaan
authors.forename: Herbert
authors.initials: H
authors.lastname: Chen
mesh_terms: D002276:Carcinoid Tumor / Q000201:enzymology* / Q000473:pathology* / Q000556:secondary; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D005770:Gastrointestinal Neoplasms / Q000201:enzymology* / Q000473:pathology*; D006801:Humans; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism
chemical_list: D051176:beta Catenin; D019908:Proto-Oncogene Proteins c-raf