title: Role of Δ133p53 in Tumor Necrosis Factor-induced survival of p53 functions in MKN45 gastric cancer cell line.
abstract: OBJECTIVE
  To explore the role of Δ133p53 in the effect of recombinant mutant human Tumor Necrosis Factor (rmhTNF) on two gastric cancer cell lines.
  
  
  METHODS
  MKN45 (with Δ133p53 expression) or SGC7901 (without Δ133p53 expression) cells were treated with rmhTNF of different concentrations only or combined with fluorouracil (5-FU), and the growth inhibition rate was detected by a cell counting kit, and apoptosis by flow cytometry. The mRNA of Δ133p53, p53, Gadd45α, MDM2, PTEN and Bax was measured by reverse transcription PCR (RT-PCR) or Nested PCR (nPCR).
  
  
  RESULTS
  On Δ133p53-positive MKN-45 cells, the effect of rmhTNF was significant in growth inhibition test (t = -9.558, p < 0.01); also, the effect of 5-FU was improved by rmhTNF with remarkable time- and dose-effect (F = 82.742, p < 0.01; F = 128.583, p < 0.01). However, on Δ133p53-negative SGC-7901 cells, no growth inhibition was showed by rmhTNF only (t = -0.121, p > 0.05). In apoptosis test, the effect of rmhTNF was significant on MKN45 cells, and the effect of 5-FU was improved significantly by rmhTNF (F = 123.931, p < 0.05). In mRNA measurement, rmhTNF-induced up-regulation of p53 accompanied with down-regulation of Δ133p53, which correlated significantly to the change of p53 downstream molecules, including MDM2, PTEN, Gadd45α, and Bax.
  
  
  CONCLUSIONS
  The results in these experiments suggested that Δ133p53 play a pivotal role in rmhTNF-induced survival of p53 functions in Δ133p53-positive MKN-45 cells.
authors.affiliation: Department of Oncology, People's Hospital of Weifang Traditional Chinese Medicine,Weifang, P.R. China. ljcwfyxy@126.com.
authors.forename: Z-M
authors.initials: ZM
authors.lastname: Shang
authors.forename: J-D
authors.initials: JD
authors.lastname: Tang
authors.forename: Q-Q
authors.initials: QQ
authors.lastname: Jiang
authors.forename: A
authors.initials: A
authors.lastname: Guo
authors.forename: N
authors.initials: N
authors.lastname: Zhang
authors.forename: Z-X
authors.initials: ZX
authors.lastname: Gao
authors.forename: W-S
authors.initials: WS
authors.lastname: Ji
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005472:Fluorouracil / Q000494:pharmacology; D016158:Genes, p53 / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D011994:Recombinant Proteins / Q000494:pharmacology; D013274:Stomach Neoplasms / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D011994:Recombinant Proteins; C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha; D005472:Fluorouracil