title: Altered claudin-4 expression in progesterone-treated endometrial adenocarcinoma cell line Ishikawa.
abstract: OBJECTIVE
  To detect the expression change of claudin-4 in Ishikawa endometrial adenocarcinoma cell line in response to progesterone. To determine whether claudin-4 is involved in the anticancer effect of progesterone.
  
  
  METHODS
  3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine the 50% inhibitory concentration (IC50) of megestrol acetate (MA) in treating Ishikawa cells. After the Ishikawa cells were treated with MA at IC50, cell apoptosis was examined by flow cytometry and transmission electron microscopy. The messenger RNA and protein expression levels of claudin-4 were further quantified by real-time polymerase chain reaction and Western blot. The localization of claudin-4 was examined by immunofluorescent staining.
  
  
  RESULTS
  The IC50 of MA on Ishikawa cells was 15 mg/L incubated for 72 hours. Apoptosis percentage was elevated from 0.07% ± 0.02% to 3.93% ± 0.81% after MA treatment. The expression of claudin-4 at both protein and messenger RNA levels was significantly decreased after the treatment of MA (P < 0.05). The localization of claudin-4 transferred from cytomembrane to cytoplasm and nucleus.
  
  
  CONCLUSIONS
  Megestrol acetate can inhibit the growth of Ishikawa cells. It may work through decreasing claudin-4 expression and cell apoptosis. The localization change of claudin-4 may also be involved in the anticancer effect of progesterone.
authors.affiliation: Department of Obstetrics and Gynecology, China-Japan Friendship Hospital, Beijing, People's Republic of China. changpanxiaoyu@163.com
authors.forename: Pan
authors.initials: P
authors.lastname: Xiao-Yu
authors.forename: Jin
authors.initials: J
authors.lastname: Yan
authors.forename: Feng
authors.initials: F
authors.lastname: Cui-Ping
authors.forename: Wang
authors.initials: W
authors.lastname: Ya-Nan
authors.forename: Lin
authors.initials: L
authors.lastname: Hua
authors.forename: L
authors.initials: L
authors.lastname: Hua-Jun
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology / Q000648:ultrastructure; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects / Q000235:genetics; D062506:Claudin-4 / Q000235:genetics* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D004353:Drug Evaluation, Preclinical; D016889:Endometrial Neoplasms / Q000235:genetics* / Q000473:pathology / Q000648:ultrastructure; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D019290:Megestrol Acetate / Q000494:pharmacology; D011374:Progesterone / Q000494:pharmacology*
chemical_list: D018931:Antineoplastic Agents, Hormonal; C568157:CLDN4 protein, human; D062506:Claudin-4; D011374:Progesterone; D019290:Megestrol Acetate