title: [Effect of forced E-cadherin expression on adhesion and proliferation of human breast carcinoma cells].
abstract: OBJECTIVE
  To investigate the role that E-cadherin (E-cad) plays on cell adhesion and proliferation of human breast carcinoma.
  
  
  METHODS
  E-cad expression vector was transfected into an E-cad-negative human breast carcinoma MDA-MB-231 cells. G418 was used to screen positive clones. E-cad, β-catenin (β-cat) and cyclin D1 expressions of these clones were confirmed by Western blot. Their cell-cell and cell-matrix adhesion abilities were detected. E-cad/β-catenin interaction was confirmed by immunoprecipitation. Cell proliferation was evaluated by MTT. Cell apoptosis was analyzed by flow cytometry. Direct two-step immunocytochemistry was used to detect the localization of β-cat.
  
  
  RESULTS
  E-cad(+) cell strains Ecad-231-7 and Ecad-231-9 were established. When cultured in ultra-low-binding dishes Ecad-231 cells grow in suspension while Ecad-231-7 and Ecad-231-9 cells grow in large clamps. When co-cultured with HCT116 cells, the average adhesion rates at 30 min are 39.0%, 60.0% and 59.5% for MDA-MB-231, Ecad-231-7 and Ecad-231-9 respectively. The average detachment rates by EDTA for 5 min are 37.4%, 4.2% and 7.4% respectively. So E-cad expression enhanced hemotypic and heterotypic cell-cell adhesion and cell-matrix adhesion. Forced exogenously expressed E-cad could combine with endogenous β-cat, whereas down stream cyclin D1 expression was significantly decreased, as evidenced by Western blot. The rates of cell apoptosis of MDA-MB-231, Ecad-231-7 and Ecad-231-9 were 1.8%, 2.0% and 2.1%. Expression of E-cad had no obvious effect on the apoptosis of tumor cells with regular culture. β-cat increased in the cytoplasma.
  
  
  CONCLUSIONS
  Two monoclonal tumor cell strains (Ecad-231-7 and Ecad-231-9) stably expressing E-cad were successfully established. E-cad could enhance adhesion and inhibit proliferation of human breast carcinoma cells through a pathway involving β-cat and cyclin D1.
authors.affiliation: Department of Pathology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing 100005, China.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Yang
authors.forename: Yu-Qin
authors.initials: YQ
authors.lastname: Liu
authors.forename: Bei
authors.initials: B
authors.lastname: Gu
authors.forename: Xiao-Cui
authors.initials: XC
authors.lastname: Bian
authors.forename: Hai-Liang
authors.initials: HL
authors.lastname: Feng
authors.forename: Zhen-Li
authors.initials: ZL
authors.lastname: Yang
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Liu
mesh_terms: D017209:Apoptosis; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D015820:Cadherins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000378:metabolism; D005260:Female; D005822:Genetic Vectors; D006801:Humans; D010957:Plasmids; D014162:Transfection; D051176:beta Catenin / Q000378:metabolism
chemical_list: D015820:Cadherins; D051176:beta Catenin; D019938:Cyclin D1