title: [Roles of KLF5 in inhibition TNFα-induced SK-BR-3 breast cancer cell apoptosis].
abstract: OBJECTIVE
  To explore the expression levels and roles of Krüpple-like factor 5 (KLF5) in tumor necrosis factor α (TNFα)-induced SK-BR-3 breast cancer cells.
  
  
  METHODS
  SK-BR-3 breast cancer cells were stimulated by TNFα at different concentrations (0, 1, 5, 10, 20 µg/L) for specified durations (0, 6, 12, 24, 36 h). Western blot was performed to detect KLF5 protein levels. Then Western blot and quantitative real-time PCR (qRT-PCR) were used to detect the expression levels of apoptosis genes. Flow cytometry and qRT-PCR were used to observe the effects of exogenous KLF5 on TNFα-induced apoptosis of SK-BR-3 breast cancer cell.
  
  
  RESULTS
  KLF5 expression levels significantly decreased in TNFα-stimulated SK-BR-3 breast cancer cells in a concentration- and time-dependent manner. Quantitative RT-PCR results showed that TNFα up-regulate apoptosis gene caspase 3, caspase 9 and bax expression levels and down-regulate bcl-1 level in SK-BR-3 cells. Adenovirus expression vectors of pAd-GFP and pAd-GFP-KLF5 were constructed and used to infect SK-BR-3 breast cancer cells. Over-expression of GFP-KLF5 inhibited apoptosis in TNFα-stimulated SK-BR-3 breast cancer cells.
  
  
  CONCLUSIONS
  TNFα reduces KLF5 expression in SK-BR-3 breast cancer cells and KLF5 participates in TNFα-induced SK-BR-3 cell apoptosis.
authors.affiliation: Affiliated Hospital of Hebei University, Baoding 071000, China.
authors.forename: Jianhong
authors.initials: J
authors.lastname: Shi
authors.forename: Caiyun
authors.initials: C
authors.lastname: Liu
authors.forename: Anyi
authors.initials: A
authors.lastname: Zhang
authors.forename: Naipeng
authors.initials: N
authors.lastname: Cui
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.forename: Baoping
authors.initials: B
authors.lastname: Chen
authors.affiliation: Email: shijianhong1980@126.com.
authors.forename: Zhenfeng
authors.initials: Z
authors.lastname: Ma
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000037:antagonists & inhibitors*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: C492214:KLF5 protein, human; D051741:Kruppel-Like Transcription Factors; D014409:Tumor Necrosis Factor-alpha