title: Cathepsin B in infiltrated lymph nodes is of prognostic significance for patients with nonsmall cell lung carcinoma.
abstract: BACKGROUND
  Tumor cells require specific proteolytic enzymes for invasion and metastasis, including lysosomal peptidases--cathepsins. Cathepsin B is a lysosomal cysteine peptidase, which appears to play a major role in invasion and metastasis of human tumors. In this study, the authors focused on the possible role of cathepsin B in lymphogenic metastasis by investigating the enzyme localization and its activity in lung tumors and corresponding tumor-infiltrated lymph nodes.
  
  
  METHODS
  Cathepsin B activity was determined in lung tumors, lung parenchyma, and tumor cell-infiltrated and noninfiltrated regional lymph nodes of the same patient. The authors investigated 35 cancer patients suffering from nonsmall cell lung carcinoma. Cathepsin B throughout activity was measured by cleavage of the fluorogenic substrate Z-Arg-Arg-AMC at pH 6.0.
  
  
  RESULTS
  The median specific cathepsin B activity was highest in tumors, followed by the infiltrated lymph nodes, noninfiltrated lymph nodes, and lung parenchyma. The authors showed a significant 1.8-fold increase in cathepsin B activity in tumor-infiltrated lymph nodes compared with noninfiltrated regional lymph nodes and a 4.5-fold increase in lung tumor tissue compared with lung parenchyma. High cathepsin B activity, both in tumors and tumor cell-infiltrated lymph nodes, indicated poor prognosis for overall survival. Immunohistochemical analysis showed the presence of cathepsin B in histiocytes and tumor cells but not in lymphocytes of lymph node tissue.
  
  
  CONCLUSIONS
  The authors' findings on higher cathepsin B levels in tumor cell-infiltrated lymph nodes show that increased level of cathepsin B activity is characteristic of the invasive tumor cell phenotype. This corroborates the hypothesis, that tumor cell associated cathepsin B may play a role in lymphogenic metastasis. The authors' results support the use of lymph node associated cathepsin B as a prognostic factor for survival of patients with lung carcinoma.
authors.affiliation: Thoraxklinik Heidelberg gGmbH, Department of Clinical Chemistry and Bacteriology, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Werle
authors.forename: C
authors.initials: C
authors.lastname: Kraft
authors.forename: T T
authors.initials: TT
authors.lastname: Lah
authors.forename: J
authors.initials: J
authors.lastname: Kos
authors.forename: U
authors.initials: U
authors.lastname: Schanzenbächer
authors.forename: K
authors.initials: K
authors.lastname: Kayser
authors.forename: W
authors.initials: W
authors.lastname: Ebert
authors.forename: E
authors.initials: E
authors.lastname: Spiess
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology* / Q000473:pathology; D002401:Cathepsin B / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008168:Lung / Q000201:enzymology; D008175:Lung Neoplasms / Q000201:enzymology* / Q000473:pathology; D008198:Lymph Nodes / Q000201:enzymology* / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016019:Survival Analysis
chemical_list: D002401:Cathepsin B