title: Glial cell line-derived neurotrophic factor promotes β-catenin phosphorylation and nuclear translocation in glioma cells.
abstract: OBJECTIVE
  Glial cell line-derived neurotrophic factor (GDNF) and N-cadherin interact to transduce intracellular signals. However, the specific molecular mechanisms of this interaction are unclear. This study attempted to detect changes in GDNF-induced β-catenin phosphorylation and nuclear translocation in C6 glioma cells.
  
  
  METHODS
  C6 glioma cells were treated with GDNF (70 ng/mL) and membrane and cytoplasmic proteins were extracted. A N-cadherin antibody was used for co-immunoprecipitation (co-IP). Western blot analysis using the co-IP protein was completed using antibodies for β-catenin, Src and β-actin. Immunocytochemistry was conducted with the same antibodies. To determine if Src induced phosphorylation of β-catenin Tyr-654, Western blot analysis was also performed on nuclear proteins from C6 cells treated with tyrosine kinase inhibitor PP2 using then p- β-catenin antibody.
  
  
  RESULTS
  After induced by GDNF, C6 cell membrane β-catenin was phosphorylated at Tyr-654 and subsequently separated from the N-cadherin/β-catenin complex. Further study confirmed that the induction by GDNF significantly increased cytoplasmic and nuclear expression of phospho-β-catenin (Tyr-654) in C6 glioma cells. There was also an increase in the binding of non-receptor protein kinase Src with N-cadherin on the inner cell membrane surface. Src induced phosphorylation of β-catenin Tyr-654 induced by GDNF decreased significantly.
  
  
  CONCLUSIONS
  The results of our study demonstrate that GDNF increases the intracellular phosphorylation level of β-catenin through N-cadherin/Src signaling, which subsequently stimulates the nuclear translocation of β-catenin. This study provides a theoretical basis for us to reveal the role of biological mechanisms on glioma cell by GDNF.
authors.affiliation: Department of Neurosurgery, Nanjing General Hospital of Nanjing Military Command, Nanjing, Jiangsu, PR China - gaodianshuai@sohu.com.
authors.forename: D
authors.initials: D
authors.lastname: Qu
authors.forename: C
authors.initials: C
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: L
authors.initials: L
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Xiong
authors.forename: D
authors.initials: D
authors.lastname: Gao
mesh_terms: D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000378:metabolism* / Q000494:pharmacology; D005910:Glioma / Q000378:metabolism*; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D010766:Phosphorylation; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D051176:beta Catenin / Q000378:metabolism*
chemical_list: C495270:CTNNB1 protein, human; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051176:beta Catenin