title: Cathepsin B: a potential prognostic marker for inflammatory breast cancer.
abstract: BACKGROUND
  Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer. In non-IBC, the cysteine protease cathepsin B (CTSB) is known to be involved in cancer progression and invasion; however, very little is known about its role in IBC.
  
  
  METHODS
  In this study, we enrolled 23 IBC and 27 non-IBC patients. All patient tissues used for analysis were from untreated patients. Using immunohistochemistry and immunoblotting, we assessed the levels of expression of CTSB in IBC versus non-IBC patient tissues. Previously, we found that CTSB is localized to caveolar membrane microdomains in cancer cell lines including IBC, and therefore, we also examined the expression of caveolin-1 (cav-1), a structural protein of caveolae in IBC versus non-IBC tissues. In addition, we tested the correlation between the expression of CTSB and cav-1 and the number of positive metastatic lymph nodes in both patient groups.
  
  
  RESULTS
  Our results revealed that CTSB and cav-1 were overexpressed in IBC as compared to non-IBC tissues. Moreover, there was a significant positive correlation between the expression of CTSB and the number of positive metastatic lymph nodes in IBC.
  
  
  CONCLUSIONS
  CTSB may initiate proteolytic pathways crucial for IBC invasion. Thus, our data demonstrate that CTSB may be a potential prognostic marker for lymph node metastasis in IBC.
authors.affiliation: Department of Pathology, National Cancer Institute, Cairo University, Giza 12613 Egypt.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Nouh
authors.forename: Mona M
authors.initials: MM
authors.lastname: Mohamed
authors.forename: Mohamed
authors.initials: M
authors.lastname: El-Shinawi
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Shaalan
authors.forename: Dora
authors.initials: D
authors.lastname: Cavallo-Medved
authors.forename: Hussein M
authors.initials: HM
authors.lastname: Khaled
authors.forename: Bonnie F
authors.initials: BF
authors.lastname: Sloane
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D002277:Carcinoma / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D002401:Cathepsin B / Q000032:analysis / Q000378:metabolism / Q000502:physiology*; D051242:Caveolin 1 / Q000378:metabolism; D005260:Female; D006801:Humans; D058922:Inflammatory Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D008207:Lymphatic Metastasis; D053858:Metabolic Networks and Pathways / Q000502:physiology; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis
chemical_list: D014408:Biomarkers, Tumor; D051242:Caveolin 1; D002401:Cathepsin B