title: Expression of extracellular signal-regulated kinase and its relationship with clinicopathological characteristics of breast cancer.
abstract: OBJECTIVE
  To investigate the expression of extracellular signal-regulated kinase (ERK) and its relationship with clinicopathological characteristics of breast cancer as well as the effect of preoperative chemotherapy on ERK expression.
  
  
  METHODS
  Expression of ERK-1 and ERK-2 protein was examined by Western blot in the breast cancer and normal breast (control) tissue of 48 patients, of whom 8 had received preoperative chemotherapy of 5'-deoxy-5-fluorouridine (5'-DFUR), with distribution of ERKs protein detected by immunohistochemical method.
  
  
  RESULTS
  Expression of ERK-1 and ERK-2 protein was increased in tumor specimen as compared with control tissue (P < 0.01). A positive correlation was observed between ERK-1 and ERK-2 (r = 0.457, P < 0.01). Protein level of ERK-1 and ERK-2 was higher in stage III patients than in stage I and stage II patients (P < 0.05). Expression of both ERK-1 and ERK-2 in the carcinoma tissue was decreased in patients who had received preoperative chemotherapy of 5'-DFUR. ERK-1 and ERK-2 proteins were mainly located in the cytoplasm.
  
  
  CONCLUSIONS
  The hyperexpression of ERK may play an important role in the initiation and development of human breast cancer. Preoperative chemotherapy of 5'-DFUR is able to partially inhibit ERK expression.
authors.affiliation: Department II of Surgery and Laboratory of Surgical Oncology, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Zhongzhao
authors.initials: Z
authors.lastname: Wang
authors.forename: Shan
authors.initials: S
authors.lastname: Wang
authors.forename: Fengxue
authors.initials: F
authors.lastname: Zhu
authors.forename: Yingjiang
authors.initials: Y
authors.lastname: Ye
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Yu
authors.forename: Xinmin
authors.initials: X
authors.lastname: Qiao
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000145:classification / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D005260:Female; D005467:Floxuridine / Q000627:therapeutic use; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000096:biosynthesis*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000096:biosynthesis*; D009367:Neoplasm Staging
chemical_list: D000964:Antimetabolites, Antineoplastic; D005467:Floxuridine; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; C025034:doxifluridine