Cathepsin B: a potential prognostic marker for inflammatory breast cancer

J Transl Med. 2011 Jan 3;9:1. doi: 10.1186/1479-5876-9-1.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biomarkers, Tumor* / analysis
  • Biomarkers, Tumor* / metabolism
  • Breast Neoplasms / diagnosis*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Carcinoma / diagnosis*
  • Carcinoma / metabolism
  • Carcinoma / pathology
  • Cathepsin B / analysis
  • Cathepsin B / metabolism
  • Cathepsin B / physiology*
  • Caveolin 1 / metabolism
  • Female
  • Humans
  • Inflammatory Breast Neoplasms / diagnosis*
  • Inflammatory Breast Neoplasms / metabolism
  • Inflammatory Breast Neoplasms / pathology
  • Lymphatic Metastasis
  • Metabolic Networks and Pathways / physiology
  • Middle Aged
  • Neoplasm Invasiveness
  • Prognosis


  • Biomarkers, Tumor
  • Caveolin 1
  • Cathepsin B