title: Synergistic in vitro anti-tumor effect of letrozole and everolimus on human endometrial carcinoma Ishikawa cells.
abstract: OBJECTIVE
  To investigate the in vitro effect of the use of combination of letrozole and everolimus on the proliferation and apoptosis of human endometrial carcinoma Ishikawa cells.
  
  
  METHODS
  Different concentrations of letrozole alone or in combination with everolimus were added to Ishikawa cell cultures in vitro. Cell viability was assessed using MTT assay. Double staining with Annexin-V-FITC was used to detect the cell apoptosis by the flow cytometry (FCM). The expression of PTEN and 4E-BP1 proteins was analyzed with Western blotting.
  
  
  RESULTS
  Letrozole by itself inhibited cell viability and decreased the invasiveness of Ishikawa cells. The anti-tumor effect of letrozole in combination with everolimus was improved compared to letrozole alone.
  
  
  CONCLUSIONS
  Letrozole and everolimus synergistically inhibit the proliferation and induce cell apoptosis by inhibiting the cell signal pathway PI3K/Akt/mTOR and inducing cell apoptosis, thus showing a promising anti-tumor effectiveness.
authors.affiliation: Department of Gynecology and Obstetrics, Xuzhou Medical College Affiliated Hospital, Xuzhou, Jiangsu Province, China. xy_lu68@aliyun.com.
authors.forename: X-Y
authors.initials: XY
authors.lastname: Lu
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: H
authors.initials: H
authors.lastname: Xu
authors.forename: T
authors.initials: T
authors.lastname: Zeng
authors.forename: Z-Z
authors.initials: ZZ
authors.lastname: Zhang
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000970:Antineoplastic Agents / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D018797:Cell Cycle Proteins; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004357:Drug Synergism; D016889:Endometrial Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D000068338:Everolimus; D005260:Female; D006801:Humans; D000077289:Letrozole; D009570:Nitriles / Q000008:administration & dosage; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D020123:Sirolimus / Q000008:administration & dosage / Q000031:analogs & derivatives; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D014230:Triazoles / Q000008:administration & dosage
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000970:Antineoplastic Agents; D018797:Cell Cycle Proteins; D000068338:Everolimus; D000077289:Letrozole; D009570:Nitriles; D051059:PTEN Phosphohydrolase; D019869:Phosphatidylinositol 3-Kinases; D010750:Phosphoproteins; D051057:Proto-Oncogene Proteins c-akt; D020123:Sirolimus; D058570:TOR Serine-Threonine Kinases; D014230:Triazoles; C087000:EIF4EBP1 protein, human; C546842:MTOR protein, human; C494929:PTEN protein, human