title: Inhibition of harringtonine-induced apoptosis by tetradecanoylphorbol acetate in human leukemia HL-60 cells.
abstract: OBJECTIVE
  To study the changes of the apoptosis induced by camptothecin (Cam) or harringtonine (Har) in human leukemia HL-60 cells after the cells were preincubated with tetradecanoylphorbol acetate (TA).
  
  
  METHODS
  Chromatin condensation observation, flow cytometry, DNA agarose gel electrophoresis, and Dot blot hybridization.
  
  
  RESULTS
  After the HL-60 cells were preincubated with TA 200 nmol.L-1 for 6 h, the apoptosis induced by Har 0.1 mg.L-1 for 3 h was drastically inhibited, and the apoptosis by Cam 0.2 mg.L-1 for 3 h was partly inhibited. On the other hand, the expression level of c-myc gene in HL-60 cells decreased apparently after the preincubation of TA.
  
  
  CONCLUSIONS
  TA preincubation inhibited the apoptosis induced by Har obviously or by Cam partly in human leukemia HL-60 cells, and the expression of c-myc gene decreased drastically in the preincubated cells, which might result in the inhibition of apoptosis.
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000037:antagonists & inhibitors*; D017209:Apoptosis / Q000187:drug effects*; D002166:Camptothecin / Q000037:antagonists & inhibitors; D002273:Carcinogens / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D016259:Genes, myc; D018922:HL-60 Cells / Q000187:drug effects; D006248:Harringtonines / Q000037:antagonists & inhibitors*; D006801:Humans; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*