title: Morphine and cancer progression: hydrogen peroxide points to need for more research.
abstract: BACKGROUND
  Morphine is widely used in the management of intractable cancer pain. However, conflicting views exist on two suspected nonanalgesic properties of morphine: suppression of immune function and inhibition of cancer progression.
  
  
  METHODS
  In vitro measurement of the tumor growth-inhibiting signaling molecule, hydrogen peroxide (H2O2), released from the cultured acute monocytic leukemia cell line, THP-1, in the presence or absence of morphine.
  
  
  RESULTS
  Morphine at concentrations of 10(-8) M significantly reduced H2O2 release from THP-1 cells.
  
  
  CONCLUSIONS
  These results provide a proof of concept for morphine's ability to inhibit H2O2 production and release in a leukemia cell system and point to a possible and as yet unrecognized tumor-promoting effect of morphine. More research is needed to systematically examine this suspected morphine-associated tumor-promoting effect.
authors.forename: Herbert
authors.initials: H
authors.lastname: Bosshart
mesh_terms: D045744:Cell Line, Tumor; D018450:Disease Progression; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000502:physiology; D009020:Morphine / Q000494:pharmacology*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000502:physiology; D009369:Neoplasms / Q000209:etiology* / Q000378:metabolism
chemical_list: D008562:Membrane Glycoproteins; D009020:Morphine; D006861:Hydrogen Peroxide; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases