title: Effects of radical oxygen species and NO: formation of intracellular hypoxia and activation of matrix metalloproteinases in tumor tissues.
abstract: OBJECTIVE
  To establish the association between the radical oxygen species (ROS) and NO levels in the tumor cells mitochondria, between cell hypoxia development and activation of matrix metalloproteinases-2 and -9.
  
  
  METHODS
  Electron paramagnetic resonance (EPR) at room temperature and at the temperature of liquid nitrogen (77 degrees K), spin traps technology, enzymography in polyacrylamide gel were applied.
  
  
  RESULTS
  Redox-centers in the respiration cascade of mitochondria have been revealed, multiple oxidative damage of which in breast and liver cancer tissues of experimental animals as well as in tumor tissue from patients with gastric cancer promote the development of cell hypoxia. Involvement of ROS and NO in activation of latent forms of matrix metalloproteinases in gastric tumor tissues has been shown.
  
  
  CONCLUSIONS
  We hypothesize that superoxide radical-anions participate in development of cell hypoxia in tumors and surrounding normal tissues inducing activation of latent forms of matrix metalloproteinases.
authors.affiliation: RE Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology, Kiev, Ukraine.
authors.forename: A P
authors.initials: AP
authors.lastname: Burlaka
authors.forename: E P
authors.initials: EP
authors.lastname: Sidorik
authors.forename: I I
authors.initials: II
authors.lastname: Ganusevich
authors.forename: S P
authors.initials: SP
authors.lastname: Osinsky
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D015687:Cell Hypoxia / Q000187:drug effects / Q000502:physiology*; D004195:Disease Models, Animal; D004578:Electron Spin Resonance Spectroscopy; D004789:Enzyme Activation; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D051381:Rats; D017382:Reactive Oxygen Species / Q000494:pharmacology*; D013274:Stomach Neoplasms / Q000473:pathology
chemical_list: D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D015127:9,10-Dimethyl-1,2-benzanthracene; D020782:Matrix Metalloproteinases