title: [Study of mechanism of medroxyprogesterone 17-acetate on the cancer stem cell-like properties of human endometrial cancer].
abstract: OBJECTIVE
  To explore the mechanism resistance of medroxyprogesterone 17-acetate(MPA) on the endometrial cancer side-population(SP) cells.
  
  
  METHODS
  (1) Ishikawa-SP cells from endometrial cancer cell lines Ishikawa were be separated by Hoechst 33342 dyeing method and flow cytometry analysis. The clone formation efficiency between Ishikawa-SP cells and Ishikawa-non-SP cells were performed by clone formation assay. Breast cancer resistance protein (BCRP) was examined by immunocytochemistry method. (2) Ishikawa, Ishikawa-SP, Ishikawa-non-SP cells were treated with various concentrations of MPA at 5, 10, 15, 20 µmol/L. After cultured for 24, 48, and 72 hours, cells growth were measured by methanethiosulfomate (MTS) assay. (3) The groups of Ishikawa, Ishikawa-SP, Ishikawa-non-SP cells incubated with MPA at the half maximal inhibitory concentration (IC50) were selected for cell apoptosis assay by using flow cytometry. After MPA treatment, the expression of caspase-3 was examined by immunocytochemistry method.
  
  
  RESULTS
  (1) There were few proportion of Ishikawa-SP cells in Ishikawa endometrial carcinoma, which were 2.7%. There were stronger clone formation efficiency for Ishikawa-SP cells than that for Ishikawa-non-SP cells in Ishikawa [(6.02 ± 1.17)% vs.(0.53 ± 0.20)%, P = 0.001]. And there were higher level expression of BCRP (P = 0.001) and also more resistant Taxol and radiation between Ishikawa-SP cells and Ishikawa-non-SP cells. (2) The inhibitory effect of MPA was concentration-dependent and time-dependent. (3)After MPA treatment, the apoptosis rates of Ishikawa-SP, Ishikawa-non-SP,Ishikawa were (4.01 ± 0.43) %, (9.30 ± 0.67) %, and (4.64 ± 0.18) %, respectively(P < 0.05). The level expression of caspase-3 in Ishikawa group after MPA treated were higher than that in Ishikawa-SP group.
  
  
  CONCLUSIONS
  MPA may be inhibit the growth of endometrial cancer, Ishikawa-SP and Ishikawa-non-SP cells, while Ishikawa-SP may be more resistant to MPA than Ishikawa-non-SP, which mechanism of resistance on MPA may be related to the properties of cancer stem-like cells and cell apoptosis.
authors.affiliation: Department of Gynecology, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Bing-jie
authors.initials: BJ
authors.lastname: Liu
authors.affiliation: Department of Gynecology, Peking University People's Hospital, Beijing 100044, China. Email: xiaopingli@hotmail.com.
authors.forename: Xiao-ping
authors.initials: XP
authors.lastname: Li
authors.affiliation: Department of Gynecology, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Li-jun
authors.initials: LJ
authors.lastname: Zhao
authors.affiliation: Department of Gynecology, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Jian-liu
authors.initials: JL
authors.lastname: Wang
authors.affiliation: Department of Gynecology, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Li-hui
authors.initials: LH
authors.lastname: Wei
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002469:Cell Separation; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm; D016889:Endometrial Neoplasms / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage / Q000494:pharmacology*; D009363:Neoplasm Proteins / Q000378:metabolism; D014411:Neoplastic Stem Cells / Q000187:drug effects* / Q000378:metabolism; D014410:Tumor Stem Cell Assay
chemical_list: C116614:ABCG2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D009363:Neoplasm Proteins; D017258:Medroxyprogesterone Acetate; C505407:CASP3 protein, human; D053148:Caspase 3