title: [Blocking TrkB-BDNF signal pathway decreases the livability of neuroblastoma cells].
abstract: OBJECTIVE
  Brain-derived neurotrophic factor (BDNF) and its specific tryrosin kinase receptor-B (TrkB) are highly correlated to the chemoresistance of neuroblastoma (NB) cells and poor prognosis. This study observed the changes of the sensibility of NB cells to chemotherapy drug cisplatin (CDDP) before and after blockage of TrkB-BDNF signal pathway by specific tyrosin kinase inhibitor K252a.
  
  
  METHODS
  Human NB cell line SH-SY5Y (SY5Y) was routinely cultured. Expression of TrkB was induced with nM all trans-retinoid acid (ATRA). Then BDNF, CDDP or K252a were added to the cultured SY5Y cells. Cell livability was assessed by methyl thiazolyl tetrazolium (MTT) assay. TrkB autophosphorylation was determined by Western blot analysis. Cell apoptosis rate was detected by flow cytometry (FCM). The conformation of apoptosis cells was observed by transmission electron microscopy (TEM).
  
  
  RESULTS
  The livability and apoptosis rate in SY5Y cells treated with ATRA, BDNF and CDDP were not different from the blank control group. However, after K252a together with ATRA, BDNF and CDDP treatment, the sensibility of SY5Y cells to chemotherapy drug CDDP increased, the livability decreased and the apoptosis rate increased in SY5Y cells when compared with the blank control group (P <0.01). K252a treatment resulted in blockage of TrkB autophosphorylation.
  
  
  CONCLUSIONS
  The blockage of TrkB-BDNF signal pathway by K252a use can increase sensibility of NB cells to chemotherapy and thus decrease the livability of NB cells.
authors.affiliation: Laboratory of Hematology, Second Affiliated Hospital of China Medical University, Shenyang 110004. zhangjihong_cmu@sina.com
authors.forename: Ji-Hong
authors.initials: JH
authors.lastname: Zhang
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Li
authors.forename: Song
authors.initials: S
authors.lastname: Chen
authors.forename: Hai-Xia
authors.initials: HX
authors.lastname: Tong
authors.forename: Ke-Ren
authors.initials: KR
authors.lastname: Zhang
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Zhang
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D019208:Brain-Derived Neurotrophic Factor / Q000037:antagonists & inhibitors*; D002227:Carbazoles / Q000494:pharmacology; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology; D006801:Humans; D026121:Indole Alkaloids / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D009447:Neuroblastoma / Q000188:drug therapy* / Q000473:pathology; D020813:Receptor, trkB / Q000037:antagonists & inhibitors*; D015398:Signal Transduction / Q000187:drug effects*; D014212:Tretinoin / Q000494:pharmacology
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D002227:Carbazoles; D026121:Indole Alkaloids; D014212:Tretinoin; C049985:staurosporine aglycone; D020813:Receptor, trkB; D002945:Cisplatin