title: [Hydrogen peroxide inhibits arsenic trioxide-induced apoptosis of Burkitt lymphoma cells].
abstract: OBJECTIVE
  To examine the effects of hydrogen peroxide (H2O2) on arsenic trioxide (As2O3)-induced apoptosis of human Burkitt lymphoma cells and evaluate the value of fluorescence microscope in analyzing cellular apoptosis.
  
  
  METHODS
  As2O3 was used to induce apoptosis in human Burkitt lymphoma cells BJAB, and the cellular changes were analyzed quantitatively using transmission electron microscope and fluorescence microscope after staining with Hoechst 33342/ propidium iodide (PI).
  
  
  RESULTS
  Under fluorescence microscope and electron microscope, BJAB cells displayed chromatin aggregation, nuclear margination and fragmentation in response to As2O3 treatment. In the presence of relatively low levels of H2O2 (200 micromol/L), the cell death resulting from apoptosis was inhibited with pyknosis and necrosis becoming the major pathway, while As2O3 failed to induce cell apoptosis. The cells showed none of the typical markers of apoptosis nor any characteristic necrotic changes, and the nuclei exhibited condensation instead of swelling. In addition, the rate of cell death induced by As2O3 was decreased in the presence of H2O2.
  
  
  CONCLUSIONS
  Low levels of H2O2 (200 micromol/L) inhibits As2O3-induced (at clinically achievable concentrations) apoptosis of the human malignant lymphoma cells. Fluorescence microscopy makes possible quantitative analysis of apoptosis, capable of distinguishing not only cell apoptosis from necrosis, but also membrane-intact from membrane-permeable apoptotic cells.
authors.affiliation: Department of Cell Biology, First Military Medical University, Guangzhou 510515, China. ludi2004@hotmail.com
authors.forename: Di
authors.initials: D
authors.lastname: Lu
authors.forename: Xiao-chun
authors.initials: XC
authors.lastname: Bai
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Xiu-mei
authors.initials: XM
authors.lastname: Li
authors.forename: Fan
authors.initials: F
authors.lastname: Deng
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Bao-luan
authors.initials: BL
authors.lastname: Cheng
authors.forename: Shen-qiu
authors.initials: SQ
authors.lastname: Luo
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000037:antagonists & inhibitors*; D002051:Burkitt Lymphoma / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D010087:Oxides / Q000037:antagonists & inhibitors*
chemical_list: D001152:Arsenicals; D010087:Oxides; D006861:Hydrogen Peroxide; D000077237:Arsenic Trioxide