Cathepsin b: a potential prognostic marker for inflammatory breast cancer

• Main Authors: Cavallo-Medved Dora, Shaalan Mohamed A, El-Shinawi Mohamed, Mohamed Mona M, Nouh Mohamed A, Khaled Hussein M, Sloane Bonnie F
• Format: Article
• Language: English
• Published: BMC 2011-01-01
• Series: Journal of Translational Medicine
• Online Access: http://www.translational-medicine.com/content/9/1/1

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>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.</p> <p>Results</p> <p>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.</p> <p>Conclusions</p> <p>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.</p>