title: PUMA overexpression induces reactive oxygen species generation and proteasome-mediated stathmin degradation in colorectal cancer cells.
abstract: Increased amounts of reactive oxygen species (ROS) induce apoptosis in mammalian cells. PUMA (P53 up-regulated modulator of apoptosis), a mitochondrial proapoptotic BH3-only protein, induces rapid apoptosis through a Bax- and mitochondria-dependent pathway. However, the molecular basis of PUMA-induced apoptosis is largely not understood. Using a combination of biophysical and biochemical methods and PUMA-inducible colorectal cells, DLD-1.PUMA, we showed that (a) PUMA-induced apoptosis is dose and time dependent; (b) PUMA-induced apoptosis is directly associated with ROS generation; (c) diphenyleneiodonium chloride, a ROS blocker, or BAX-inhibiting peptide, a suppressor of BAX translocation, decreased ROS generation and apoptosis in DLD-1.PUMA cells; (d) overexpression of PUMA induced up-regulation (>1.34-fold) of peroxiredoxin 1 and down-regulation (by 25%) of stathmin through proteasome-mediated degradation; and (e) hydrogen peroxide down-regulated stathmin and disrupted the cellular microtubule network. Our findings indicate that PUMA induces apoptosis, in part, through the BAX-dependent generation of superoxide and hydrogen peroxide. ROS overproduction and oxidative stress induce proteome-wise alterations, such as stathmin degradation and disorganization of the cell microtubule network, in apoptotic cells.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131-001, USA.
authors.forename: Zhihe
authors.initials: Z
authors.lastname: Liu
authors.forename: Huimei
authors.initials: H
authors.lastname: Lu
authors.forename: Honglian
authors.initials: H
authors.lastname: Shi
authors.forename: Yuchun
authors.initials: Y
authors.lastname: Du
authors.forename: Jian
authors.initials: J
authors.lastname: Yu
authors.forename: Sheng
authors.initials: S
authors.lastname: Gu
authors.forename: Xian
authors.initials: X
authors.lastname: Chen
authors.forename: Ke Jian
authors.initials: KJ
authors.lastname: Liu
authors.forename: Chien-An A
authors.initials: CA
authors.lastname: Hu
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D008868:Microtubule Proteins / Q000187:drug effects / Q000378:metabolism*; D008928:Mitochondria / Q000187:drug effects; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009861:Onium Compounds / Q000494:pharmacology; D010446:Peptide Fragments; D010544:Peroxidases / Q000378:metabolism; D054464:Peroxiredoxins; D010750:Phosphoproteins / Q000187:drug effects / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000037:antagonists & inhibitors; D017382:Reactive Oxygen Species / Q000378:metabolism*; D050777:Stathmin; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000172:deficiency / Q000378:metabolism*; D051028:bcl-2-Associated X Protein
chemical_list: D051017:Apoptosis Regulatory Proteins; C494826:BAX protein, human; C438378:BBC3 protein, human; D004791:Enzyme Inhibitors; D008868:Microtubule Proteins; D009861:Onium Compounds; D010446:Peptide Fragments; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; C493995:STMN1 protein, human; D050777:Stathmin; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; C007517:diphenyleneiodonium; D006861:Hydrogen Peroxide; D010544:Peroxidases; C515940:PRDX1 protein, human; D054464:Peroxiredoxins; D019001:Nitric Oxide Synthase; D046988:Proteasome Endopeptidase Complex