title: Induction of apoptosis by deinoxanthin in human cancer cells.
abstract: BACKGROUND
  Deinoxanthin is unique carotenoid isolated from the radioresistant bacterium Deinococcus radiodurans. In the present study, the induction of apoptosis of cancer cells by deinoxanthin was investigated.
  
  
  METHODS
  Apoptotic effects were evaluated in HepG2, PC-3, and HT-29 cells, and were measured through cell viability, morphological changes, and a DNA fragmentation assay. Intracellular generation of reactive oxygen species (ROS) was measured using 5-(and 6-)-carboxy-2',7'-dichlorodihydrofluorescein diacetate (carboxy-H2DCF-DA). The expression of apoptotic and anti-apoptotic proteins was assayed by western blotting.
  
  
  RESULTS
  The half-maximal inhibitory concentration (IC50) values for deinoxanthin against the HepG2, HT-29, and PC-3 cell lines were 59 μM, 61 μM, and 77 μM, respectively. Deinoxanthin treatment caused an increase in ROS in all tested cells, suggesting possible pro-oxidant activity of deinoxanthin. Pro-caspase-3 was degraded in cancer cells by deinoxanthin treatment. Moreover, BCL2 expression decreased, but that of BAX increased.
  
  
  CONCLUSIONS
  The present findings demonstrate for the first time the novel functional property of deinoxanthin isolated from radioresistant bacteria as a potent inducer of apoptosis in cancer cells. These data suggest that deinoxanthin could be potentially useful as a chemopreventive agent.
authors.affiliation: Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju 500-757, South Korea. choiji01@jnu.ac.kr.
authors.forename: Yong-Ji
authors.initials: YJ
authors.lastname: Choi
authors.forename: Jung-Mu
authors.initials: JM
authors.lastname: Hur
authors.forename: Sangyong
authors.initials: S
authors.lastname: Lim
authors.forename: Minho
authors.initials: M
authors.lastname: Jo
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Kim
authors.forename: Jong-Il
authors.initials: JI
authors.lastname: Choi
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002338:Carotenoids / Q000494:pharmacology*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; C547822:deinoxanthin; D002338:Carotenoids; D053148:Caspase 3
keywords: Deinoxanthin; apoptosis; cancer cells; reactive oxygen species