title: [Study on p53, mdm-2 and p21WAF1 protein expression in ER-positive and ER-negative human breast cancer cell lines and its relation to biological features].
abstract: OBJECTIVE
  To study p53, mdm-2 and p21WAF1 protein expression levels in ER-positive and ER-negative human breast cancer cell lines and their relations to biological features.
  
  
  METHODS
  Using cell culture, DNA stable transfection and immunohistochemical methods, the protein expression levels of p53, mdm-2 and WAF1 genes in ER-positive expressing wtp53 MCF-7 cells, ER-negative expressing mtp53 MDA-MB-231 cells and ER-transfected MDA-MB-231 cells were determined, and then, their relation to biological features were compared.
  
  
  RESULTS
  (1) The function and expression of p53 protein of MCF-7 and MDA-MB-231 cells were obviously different. The expression levels of mdm-2 and p21WAF1 proteins in MCF-7 cells were higher than those of MDA-MB-231 cells (P < 0.05), The biological features of the former were more favorable than those of the latter. (2) The ER-transfected MDA-MB-231 cells showed lower expression of mtp53 and higher expression of mdm-2 protein (P < 0.05), but no significant difference from that of p21WAF1 protein (P > 0.05). Meanwhile, biological features leading to favorable prognosis were manifested.
  
  
  CONCLUSIONS
  The ER status of breast cancer cell lines is related to the expression level of p53 and mdm-2 proteins and the biological features.
authors.affiliation: Department of Surgery, Cancer Hospital, Shanghai Medical University.
authors.forename: M
authors.initials: M
authors.lastname: Jiang
authors.forename: Z
authors.initials: Z
authors.lastname: Shao
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D001943:Breast Neoplasms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis*; D006801:Humans; D009363:Neoplasm Proteins / Q000096:biosynthesis; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D051736:Proto-Oncogene Proteins c-mdm2; D011960:Receptors, Estrogen / Q000032:analysis*; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D011960:Receptors, Estrogen; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2