title: Beauvericin induces cytotoxic effects in human acute lymphoblastic leukemia cells through cytochrome c release, caspase 3 activation: the causative role of calcium.
abstract: Beauvericin (BEA), a cyclic hexadepsipeptide, induces cell death in human leukemia cells (CCRF-CEM) and the process of BEA-induced cell death has been speculated to undergo an apoptotic pathway. In the present study, several well-characterized factors, known to play important roles in apoptotic pathway, were investigated in BEA-induced CCRF-CEM cell death. CCRF-CEM cells were treated with BEA at concentrations from 1 to 10 microM for up to 24 h. The incidence of nuclear fragmentation and apoptotic body formation in the cells, cytosolic caspase-3 activity, mitochondrial membrane potential, and release of cytochrome c (Cyt c) from mitochondria in BEA-treated cells were determined and compared with that in untreated cells. Moreover, to investigate the role of intracellular Ca++ in this cell death process, CCRF-CEM cells were primed with 3 microM of BAPTA/AM, a Ca++ chelator, to exclude intracellular Ca++ prior to the BEA treatment. The data revealed that BEA-induced cell death in CCRF-CEM cells exhibited a dose- and time-dependent manner. The incidence of nuclear fragmentation and apoptotic body formation was significantly increased in CCRF-CEM cells treated with BEA at concentrations of 1 microM or greater. Increase of cytosolic caspase-3 activity was also observed in BEA-treated cells with a dose-dependent manner. In addition, increased release of Cyt c from mitochondria was also observed in the cells treated with 10 microM BEA in a time-dependent pattern. The BAPTA/AM pretreatment partially blocked BEA-induced cell death in CCRF-CEM cells, indicating that intracellular Ca++ plays an important role, maybe as a mediator in cell death signaling, in this cell death pathway. The results support the notion that BEA-induced cell death in CCRF-CEM cells likely undergo through an apoptotic pathway on the basis of increase of release of Cyt c from mitochondria, increase of caspase-3 activity, and some observed typical apoptotic cellular changes in morphology.
authors.affiliation: School of Medicine, Fu Jen Catholic University, 510, Chung-Cheng Road, Hsin-Chuang, Taipei Hsien 242, Taiwan. nurs1019@mails.fju.edu.tw
authors.forename: Guey-Mei
authors.initials: GM
authors.lastname: Jow
authors.forename: Cheng-Jen
authors.initials: CJ
authors.lastname: Chou
authors.forename: Bing-Fang
authors.initials: BF
authors.lastname: Chen
authors.forename: Jia-Huei
authors.initials: JH
authors.lastname: Tsai
mesh_terms: D017209:Apoptosis; D002118:Calcium / Q000378:metabolism*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D016923:Cell Death; D045744:Cell Line, Tumor; D002614:Chelating Agents / Q000494:pharmacology; D045304:Cytochromes c / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D047630:Depsipeptides / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D009025:Morpholines / Q000494:pharmacology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma
chemical_list: D002614:Chelating Agents; D047630:Depsipeptides; D009025:Morpholines; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; C004456:beauvericin; D004533:Egtazic Acid; C085610:lateritin; D045304:Cytochromes c; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D002118:Calcium