title: Lycium barbarum polysaccharide stimulates proliferation of MCF-7 cells by the ERK pathway.
abstract: OBJECTIVE
  The aim of this study was to investigate the anti-proliferative effect of Lycium barbarum polysaccharide (LBP) on MCF-7 cells.
  
  
  METHODS
  MCF-7 cells were treated with 0, 10, 30, 100, and 300 μg/ml LBP for 24 h. The cell cycle distribution was analyzed by flow cytometry. MEK inhibitor, U1206 also was added in MCF-7 cells to deal with LBP (300 μg/ml) for different times (0, 2, 4, 6, 8, 16, 24 h). Western blotting was used to indicate changes in the levels of ERK (extracellular signal-regulated protein kinase) and phosphorylation-ERK (p-ERK) to compare the relationship between ERK activity and LBP. The expressions of p53, p-p53 and p21 were observed by western blotting to analyze the relationship between p53 and ERK which was under the treatment of LBP.
  
  
  RESULTS
  The MCF-7 cell cycle was arrested in S phase with the treatment of LBP. The LBP can also activate ERK, which may be associated with p53 pathway. There was a dose-dependent increase in the relation between the degree of ERK activation and LBP.
  
  
  CONCLUSIONS
  LBP induces the anti-proliferation of MCF-7 cells by activating ERK.
authors.affiliation: Department of Pharmacy, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, PR China. woodshen2000@yahoo.com.cn
authors.forename: Lingling
authors.initials: L
authors.lastname: Shen
authors.forename: Guang
authors.initials: G
authors.lastname: Du
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000494:pharmacology*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D059807:S Phase Cell Cycle Checkpoints / Q000187:drug effects; D013997:Time Factors; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D050759:Cyclin-Dependent Kinase Inhibitor p21; D004365:Drugs, Chinese Herbal; D047428:Protein Kinase Inhibitors; D016159:Tumor Suppressor Protein p53; C500223:lycium barbarum polysaccharide