title: [Transfection of the tumor metastasis suppressor gene nm23-H1 can targetly suppress the activity of extracellular signal-regulated protein kinase (ERK) in human high-metastasis large cell lung cancer cell line L9981].
abstract: BACKGROUND
  To investigate the influence of the tumor metastasis suppressor gene nm23 H1 on the activity of extracellular signal-regulated protein kinase (ERK) in human high metastasis large cell lung cancer cell line L9981.
  
  
  METHODS
  The levels of total ERK1/2 and phospho-pERK1/2 were determined with p44/42 MAP kinase antibody and dually phosphospecific phospho-44/42 MAP kinase antibody in human high-metastasis large cell lung cancer cell lines L9981 (cell line with nm23-H1 gene deletion), L9981-nm23-H1 (cell line with nm23-H1 transfected ) and L9981-PLXSN (cell line with vector transfected) by Western blot method, respectively. The activity of phospho-ERK1/2 was determined with an ERK1/2 assay kit by immunopreciptation and Western blot analysis.
  
  
  RESULTS
  The expression levels of phospho-ERK1/2 kinase and the activity of phospho-ERK1/2 in the lung cancer cell line L9981-nm23-H1 were remarkably higher than those of the L9981 cell line and L9981-PLXSN cell line ( P < 0.01), but no significant difference in both the phospho-ERK1/2 expression and phospho-ERK1/2 activity was observed between the L9981 and L9981-PLXSN cell lines ( P > 0.05). There was no significant difference in the total ERK1/2 level among the three cell lines.
  
  
  CONCLUSIONS
  nm23-H1 gene can obviously targetly suppress the activity of ERK1/2 in human high metastasis large cell lung cancer cell line L9981. This suggest that the mechanisms of nm23-H1 gene as a tumor metastasis suppressor gene may be related to its suppression to the MAPK/ERK signal transduction pathway.
authors.affiliation: Key Laboratory of Lung Cancer Molecular Biology of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R.China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Li
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Zhou
authors.forename: Zhilin
authors.initials: Z
authors.lastname: Sun
authors.forename: Yang
authors.initials: Y
authors.lastname: Qin
authors.forename: Wen
authors.initials: W
authors.lastname: Zhu
authors.forename: Yanping
authors.initials: Y
authors.lastname: Wang
authors.forename: Lunxu
authors.initials: L
authors.lastname: Liu
authors.forename: Xiaohe
authors.initials: X
authors.lastname: Chen
authors.forename: Zefang
authors.initials: Z
authors.lastname: Sun