title: Mitochondria-mediated and p53-associated apoptosis induced in human cancer cells by a novel selenophene derivative, D-501036.
abstract: D-501036 [2,5-bis(5-hydroxymethyl-2-selenienyl)-3-hydroxymethyl-N-methylpyrrol], a novel selenophene derivative, is a highly potent cytotoxic agent with broad spectrum antitumor activity. The present study was undertaken to explore the mechanism(s) through which D-501036 exerts its action mode on the cancer cell death. D-501036 was found to suppress the growth of KB and HepG(2) cells in an irreversible manner. The results of annexin-V assays and PARP cleavage studies were consistent with the D-501036-induced apoptosis. Findings provided a strong support for the induction of mitochondria-mediated apoptosis by this drug. The examination of two canonical pathways of initiation caspases, those for caspases -8 and -9, revealed that caspase-9 protein and the activities of caspases -9 and -3 were increased in a dose- and time-dependent manner. The concentrations of Fas/Fas-L and procaspase-8 and the activity of caspase-8 were not altered. Furthermore, the mitochondrial membrane potential permeability and the release of cytochrome c to the cytosol were both increased by D-501036. The concentrations of the pro-apoptotic protein Bax and translocation of Bax from the cytosol to the mitochondria were increased in response to D-501036, whereas the concentrations of the anti-apoptotic protein Bcl-2 were decreased. Two DNA damage-related pro-apoptotic proteins, Puma and Noxa, were upregulated in a dose- and time-dependent manner. These pro-apoptotic and anti-apoptotic proteins are downstream effectors of p53. Accordingly, the phosphorylated and total forms of p53 were induced and p53 was translocated from the cytosol to the mitochondria in response to D-501036 treatment. Collectively, we conclude that D-501036 induces cellular apoptosis through the p53-associated mitochondrial pathway.
authors.affiliation: Institute of Cancer Research, National Health Research Institutes, Taipei, Taiwan.
authors.forename: Her-Shyong
authors.initials: HS
authors.lastname: Shiah
authors.forename: Wan-Shu
authors.initials: WS
authors.lastname: Lee
authors.forename: Shin-Hun
authors.initials: SH
authors.lastname: Juang
authors.forename: Pao-Chiung
authors.initials: PC
authors.lastname: Hong
authors.forename: Chia-Chi
authors.initials: CC
authors.lastname: Lung
authors.forename: Ching-Jer
authors.initials: CJ
authors.lastname: Chang
authors.forename: Kai-Ming
authors.initials: KM
authors.lastname: Chou
authors.forename: Jang-Yang
authors.initials: JY
authors.lastname: Chang
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D045304:Cytochromes c / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008928:Mitochondria / Q000378:metabolism*; D015394:Molecular Structure; D016566:Organoselenium Compounds / Q000737:chemistry / Q000494:pharmacology*; D011758:Pyrroles / Q000737:chemistry / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: C517977:2,5-bis(5-hydroxymethyl-2-selenienyl)-3-hydroxymethyl-N-methylpyrrole; D000970:Antineoplastic Agents; D016566:Organoselenium Compounds; D011758:Pyrroles; D016159:Tumor Suppressor Protein p53; D045304:Cytochromes c; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9