title: [Effect of caffeine on camptothecin-induced apoptosis of Molt-4 cells].
abstract: OBJECTIVE
  Caffeine could act on cell cycle checkpoints and affect the progression of cell cycle, but its impact on apoptosis of tumor cells is in debate. This study was carried out to investigate the effects of caffeine on camptothecin-induced apoptosis and cell cycle checkpoints of leukemia cell line Molt-4.
  
  
  METHODS
  The cell apoptosis was induced by camptothecin, and caffeine was used to interfere with cell cycle checkpoints. The apoptosis rate and cell cycle during apoptosis were analyzed using sub-G1 method and Annexin V-propidium iodide (Annexin V/PI) staining.
  
  
  RESULTS
  Caffeine (2.0-20.0 mmon/L) had no effect on proliferation of Molt-4 cells in exponentially growth phase. Camptothecin selectively induced apoptosis of Molt-4 cells in S phase; when induced with camptothecin (0.15 micromol/L) for 4 or 6 h, the apoptosis rates were (23.69+/-2.26)% and (36.99+/-1.42)%. This cell cycle-specific apoptosis were inhibited obviously by caffeine with the apoptosis rates of (4.79+/-0.64)% and (2.69+/-0.56)%. When caffeine was removed, the apoptosis rates increased obviously to (46.23+/-0.21)% and (55.81+/-0.41)%, and still mainly happened in S phase.
  
  
  CONCLUSIONS
  Caffeine could inhibit camptothecin-induced apoptosis of Molt-4 cells. As a drug acting on cell cycle checkpoints, caffeine could transiently shield the surveillance of checkpoints to damaged cells and inhibit cell apoptosis. The effect may be reversed when caffeine is removed away.
authors.affiliation: Molecular Medicine Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P. R. China.
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Tan
authors.forename: Yong-Dong
authors.initials: YD
authors.lastname: Feng
authors.forename: De-Ding
authors.initials: DD
authors.lastname: Tao
authors.forename: Hui
authors.initials: H
authors.lastname: Xiao
authors.forename: Da-Xing
authors.initials: DX
authors.lastname: Xie
authors.forename: Cong-Nian
authors.initials: CN
authors.lastname: Yu
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Gong
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D002110:Caffeine / Q000494:pharmacology*; D002166:Camptothecin / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D015458:Leukemia, T-Cell / Q000473:pathology*; D016196:S Phase
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D002110:Caffeine; D002166:Camptothecin