title: Activity of cysteine protease inhibitors in human brain tumors.
abstract: BACKGROUND
  Cysteine proteases (mainly cathepsins B and L) are thought to play an important role in the progress of cancer, including brain tumors. Together with other proteases, they hydrolyze the extracellular matrix and basement membrane proteins, thus enabling the tumor to grow and spread. Therefore cysteine protease inhibitors are regarded as protective factors, able to prevent tumor growth and dissemination.
  
  
  METHODS
  In this study, the activity of cysteine protease inhibitors (CPIs) was investigated in material derived from patients with brain tumors (astrocytoma and meningioma). The activity of CPIs was measured as antipapain activity in tissue homogenates, cerebrospinal fluid, and serum, with N-benzoyl-DL-arginine-2-naphthylamide hydrochloride (BANA) as a substrate, according to Barret's method.
  
  
  RESULTS
  Tumorous tissues showed higher activity of cysteine protease inhibitors than control tissues, but this difference proved to be statistically insignificant. The activity of CPIs was lower in cerebrospinal fluid and serum from patients with brain tumors.
  
  
  CONCLUSIONS
  The activity of CPIs measured in brain tumor tissue cannot be taken as a marker of any type of tumor, whereas CPI activity in cerebrospinal fluid and serum may be considered a marker of meningioma. In meningioma patients the level of CPIs may be too low to prevent the host tissues from the growing tumor.
authors: Department of Medical Biochemistry, Medical University, Wroclaw, Poland. iza@bioch.am.wroc.pl
authors: I
authors: I
authors: Berdowska
authors: M
authors: M
authors: Siewiński
authors: A
authors: A
authors: Zarzycki-Reich
authors: J
authors: J
authors: Jarmułowicz
authors: L
authors: L
authors: Noga
mesh_terms: D001254:Astrocytoma / Q000378:metabolism*; D001932:Brain Neoplasms / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000134:cerebrospinal fluid / Q000378:metabolism*; D006801:Humans; D008579:Meningioma / Q000378:metabolism*
chemical_list: D015853:Cysteine Proteinase Inhibitors