title: [Effects of genistein on apoptosis in HCT-116 human colon cancer cells and its mechanism].
abstract: OBJECTIVE
  To investigate the effects of genistein on cell proliferation and apoptosis in HCT-116 human colon cancer cells and its possible mechanism.
  
  
  METHODS
  After treatment with genistein, cell proliferation was determined by MTT assay. Cell cycle, cell apoptosis, intracellular reactive oxygen species ( ROS) and mitochondrial membrane potential were determined by flow cytometry. Furthermore, ultrastructural change was observed using transmission electron microscopy (TEM).
  
  
  RESULTS
  Genistein inhibited cell proliferation in a dose- and time-dependent manner. Genistein treatment in 0 - 100 micromol/L resulted in G2/M cell cycle arrest. The ratio of Sub-G1 increased from (1.63 +/- 0.44)% to (8.33 -1.51)% (P < 0.01). The ratio of early apoptosis increased from (1.93 +/- 0.32)% to (7.25 +/- 0.86)% (P < 0.01). Genistein caused characteristic apoptotic changes in TEM observation. Genistein treatment in 100 micromol/L increased intracellular ROS level to a peak at 2 h [2 h, (15.53 +/- 1.55)% vs. 0 h, (8.57 +/- 0.35)%, P < 0.01] and decreased mitochondrial membrane potential to a bottom at 1 h [1 h, (0.82 +/- 0.02)% vs. 0 h, (6.70 +/- 0.21)%, P < 0.01).
  
  
  CONCLUSIONS
  Our findings indicated that genistein inhibits cell proliferation, induces G2/M cell cycle arrest and apoptosis in colon cancer cell line HCT-116, with the increase of intracellular ROS level and decrease of mitochondrial membrane potential.
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou 215123, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou 215123, China.
authors.forename: Jiaying
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou 215123, China.
authors.forename: Shufen
authors.initials: S
authors.lastname: Han
authors.affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou 215123, China.
authors.forename: Liqiang
authors.initials: L
authors.lastname: Qin
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D019833:Genistein / Q000494:pharmacology*; D045325:HCT116 Cells; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D019833:Genistein