title: Regulation of bcl-2 family in hydrogen peroxide-induced apoptosis in human leukemia HL-60 cells.
abstract: Numerous types of cells have been shown to undergo apoptosis when exposed to oxidant agent such as hydrogen peroxide. In order to understand the functional relationship between the anti- and pro-apoptotic regulatory proteins in the cells under oxidant stress, we have studied the level of expression of apoptosis regulatory proteins, bcl-2 and bax, in human leukemia HL-60 cells. The exposure of HL-60 cells to different concentrations of H2O2 for 6 h resulted in a typical apoptosis of the cells as characterized by flow cytometry, cell cycle analysis, and DNA fragmantation. There was a block in G1 to S transition and apoptotic cells were mainly derived from S and G2 cells. Kinetic study demonstrated that the levels of both bcl-2-mRNA and -protein expression were decreased with the progression of cellular apoptosis whereas the level of bax-mRNA was unchanged but the expressed bax-protein was not detectable. Cycloheximide, a nonspecific translation inhibitor, did not prevent the hydrogen peroxide-mediated apoptosis in HL-60 cells. These results suggest that the regulation of bcl-2, but not of bax are important factor in the oxidative stress-induced apoptosis in HL-60 cells.
authors.affiliation: Department of Pediatrics, Korea University, Seoul.
authors.forename: J E
authors.initials: JE
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Sohn
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.forename: K C
authors.initials: KC
authors.lastname: Lee
authors.forename: C S
authors.initials: CS
authors.lastname: Son
authors.forename: Y C
authors.initials: YC
authors.lastname: Tockgo
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D003513:Cycloheximide / Q000494:pharmacology; D053938:DNA Fragmentation; D004273:DNA, Neoplasm / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D018922:HL-60 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D016877:Oxidants / Q000494:pharmacology*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D051028:bcl-2-Associated X Protein
chemical_list: C494826:BAX protein, human; D004273:DNA, Neoplasm; D016877:Oxidants; D011500:Protein Synthesis Inhibitors; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein; D003513:Cycloheximide; D006861:Hydrogen Peroxide