title: Current status of the molecular mechanisms of anticancer drug-induced apoptosis. The contribution of molecular-level analysis to cancer chemotherapy.
abstract: Apoptosis is an important phenomenon in cytotoxicity induced by anticancer drugs. Here, we review the current status of the molecular mechanisms of anticancer drug-induced apoptosis in order to assess the contribution of molecular-level analysis to cancer chemotherapy. It is apparent that the molecular mechanisms by which anticancer drugs induce apoptosis are mediated by death receptor-dependent and -independent pathways, which are related to the release of cytochrome c through voltage-dependent anion channels in the mitochondrial inner membrane. The release of cytochrome c is the central gate in turning on/off apoptosis, and is regulated by the interaction of proapoptotic proteins, including Bid, Bax and Bak, and antiapoptotic proteins including Bcl-2 and Bcl-X(L), and a specific class of inhibitors of apoptosis proteins (IAPs) including Akt, survivin, and heat-shock proteins. The caspase cascade is activated by the release of cytochrome c, which is initiated by the formation of apoptosomes consisting of procaspase-9, Apaf-1 and cytochrome c in the presence of dATP, and results in the activation of caspase-9 and caspase-3, thereby leading to apoptosis. Drug sensitivity can be enhanced by the introduction of proapoptotic genes and the inhibition of antiapoptotic proteins. The latter process is mediated by antisense oligonucleotides and is associated with apoptosis. The signal transduction pathways that are triggered by the central gate in mitochondria play a critical role in anticancer drug-induced apoptosis. The modulation of signal transduction pathways targeting the proteins involved in these signal transduction pathways using antisense IAPs, and growth factor antibodies may be a good strategy for enhancing therapeutic efficacy of anticancer drugs in cancer chemotherapy.
authors.affiliation: International Radiation Information Center, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Japan. rkim@hiroshima-u.ac.jp
authors.forename: Ryungsa
authors.initials: R
authors.lastname: Kim
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Tanabe
authors.forename: Yoko
authors.initials: Y
authors.lastname: Uchida
authors.forename: Manabu
authors.initials: M
authors.lastname: Emi
authors.forename: Hideki
authors.initials: H
authors.lastname: Inoue
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Toge
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D001692:Biological Transport / Q000187:drug effects; D003574:Cytochrome c Group / Q000378:metabolism; D015195:Drug Design; D005544:Forecasting; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D007473:Ion Channels / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D009363:Neoplasm Proteins / Q000235:genetics / Q000502:physiology; D009369:Neoplasms / Q000188:drug therapy / Q000473:pathology; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D018124:Receptors, Tumor Necrosis Factor / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D003574:Cytochrome c Group; D007473:Ion Channels; D009363:Neoplasm Proteins; D016376:Oligonucleotides, Antisense; D018124:Receptors, Tumor Necrosis Factor