title: [Effects of deguelin on proliferation and apoptosis of MCF-7 breast cancer cells by phosphatidylinositol 3-kinase/Akt signaling pathway].
abstract: OBJECTIVE
  To study the effects of deguelin on proliferation and apoptosis of human breast cancer cell line MCF-7 and on phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway.
  
  
  METHODS
  After treatment with 0, 1, 5, 10, 15 and 20 μmol/L of deguelin for 6, 24, 48 and 72 hours, the proliferation inhibition rate of MCF-7 cells was measured by cell counting kit-8 assay. Apoptosis rate of MCF-7 cells was detected with Annexin V-fluorescein isothiocyanate/propidium iodide double staining by flow cytometry and the apoptotic morphology was observed under a transmission electron microscope. After treatment with 0, 1 and 5 μmol/L of deguelin for 6 hours, 5 proteins involved in the PI3K/Akt signaling pathway were examined by Western blot analysis.
  
  
  RESULTS
  Deguelin at doses of 5, 10, 15 and 20 μmol/L inhibited the proliferation of MCF-7 cells at 6, 24, 48 and 72 hours. There was a significant difference in each group compared with the control group (P<0.01). The inhibitory effect was more marked with increasing concentration and duration of treatment. There were statistical differences (P<0.05) among 5, 10, 15 and 20 μmol/L groups. However, 1 μmol/L of deguelin had no obvious effects on the proliferation of MCF-7 cells at 6, 24, 48 and 72 hours, showing no significant difference compared with control group (P>0.05). Deguelin at doses of 5, 10, 15 and 20 μmol/L induced apoptosis of MCF-7 cells at 6 hours. There were significant differences (P<0.01) in the early and late apoptosis rate between the treated groups and the control group. The typical apoptotic MCF-7 cells were observed under the transmission electron microscopy. However, 1 μmol/L of deguelin had no apparent effect in inducing apoptosis of MCF-7 cells at 6 hours. After treatment with 5 μmol/L of deguelin for 6 hours the expression of phosphorylated phosphatase and tensin homologue deleted on chromosome 10 (PTEN) (Ser380), phosphorylated 3-phosphoinositide-dependent protein kinase 1 (PDK1) (Ser241), phosphorylated Akt (Thr308) and phosphorylated glycogen synthase kinase-3β (GSK-3β) (Ser9) proteins were significantly reduced in MCF-7 cells, while there was no significant change in the expression of total Akt protein. However, after treatment with 1 μmol/L of deguelin for 6 hours, there was no apparent change in the expression of these 5 proteins.
  
  
  CONCLUSIONS
  Deguelin can inhibit the phosphorylation of GSK-3β (Ser9) via inhibition of the phosphorylation of PTEN (Ser380) and PDK1 (Ser241) pathway, thus inducing apoptosis and inhibiting proliferation of MCF-7 cells.
authors.affiliation: Department of Oncology, Huashan Hospital, Fudan University, Shanghai 200040, China.
authors.forename: Zhao-hui
authors.initials: ZH
authors.lastname: Chu
authors.forename: Xiao-hua
authors.initials: XH
authors.lastname: Liang
authors.forename: Xin-li
authors.initials: XL
authors.lastname: Zhou
authors.forename: Ruo-fan
authors.initials: RF
authors.lastname: Huang
authors.forename: Qiong zhan
authors.initials: Qz
authors.lastname: Zhan
authors.forename: Jing-wei
authors.initials: JW
authors.lastname: Jiang
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000378:metabolism; D045744:Cell Line, Tumor / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D005260:Female; D006801:Humans; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012402:Rotenone / Q000031:analogs & derivatives* / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D012402:Rotenone; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; C107676:deguelin