title: Beclin 1 augmented cis-diamminedichloroplatinum induced apoptosis via enhancing caspase-9 activity.
abstract: Beclin 1, identified as a Bcl-2-interacting protein, is known to enhance autophagy. However, the effect of Beclin 1 on apoptotic signaling has remained unclear. Here, we show that overexpression of Beclin 1 in MKN28 human gastric cancer cells augmented cis-diamminedichloroplatinum (CDDP)-induced apoptosis. Conversely, "knockdown" of Beclin 1 by a small inhibitory RNA in MKN 1 cells attenuated this cytotoxicity. Furthermore, not only caspase-3/7 activities, but also caspase-9 activity was increased in Beclin 1 gene transfectants treated with CDDP, and caspase-9 inhibitor completely abolished augmentation of CDDP-induced apoptosis by Beclin 1 as did a caspase-3 inhibitor. Thus, Beclin 1 augments CDDP-induced apoptosis through enhancing caspase-9 activity and functions as a pro-apoptotic molecule.
authors.affiliation: Department of Clinical Laboratory Medicine, Sapporo Medical University, School of Medicine, South-1, West-16, Chuo-ku, Sapporo 060-8543, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Furuya
authors.forename: Naoki
authors.initials: N
authors.lastname: Tsuji
authors.forename: Atsuhito
authors.initials: A
authors.lastname: Yagihashi
authors.forename: Naoki
authors.initials: N
authors.lastname: Watanabe
mesh_terms: D000970:Antineoplastic Agents / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D000071186:Beclin-1; D015153:Blotting, Western; D053148:Caspase 3; D053179:Caspase 7; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism*; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000633:toxicity*; D004789:Enzyme Activation / Q000187:drug effects; D004792:Enzyme Precursors / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006801:Humans; D008565:Membrane Proteins; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011233:Precipitin Tests; D011506:Proteins / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D013274:Stomach Neoplasms / Q000235:genetics / Q000473:pathology
chemical_list: D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; D004792:Enzyme Precursors; D008565:Membrane Proteins; D011506:Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D011065:Poly(ADP-ribose) Polymerases; C505407:CASP3 protein, human; C505520:CASP7 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053179:Caspase 7; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D002945:Cisplatin