الفهرس | Only 14 pages are availabe for public view |
Abstract Inflammatory breast cancer (IBC) is the most aggressive and lethal form of breast cancer. It is characterized by a high metastatic potential. In spite of trials of scientists to identify new biomarkers and to understand the molecular mechanisms underlying IBC pathogenesis, the role and expression pattern of heparanase (HPSE) and cathepsin L (CTSL) is still unexplored. HPSE is the only mammalian endoglycosidase degrading heparan sulfate (HS), the main polysaccharide chain of extracellular matrix, facilitating the metastasis of tumor cells. Cathepsin L (CTSL), lysosomal cysteine proteinase belongs to the papain subfamily of cysteine proteases1, is responsible for activation of HPSE. Therefore, we characterized the mRNA expression levels of HPSE and its activator CTSL in IBC (n = 20) versus non-IBC (n = 20) using quantitative real-time PCR. Further, we immunostained HPSE protein in IBC (n = 20) vs. non-IBC (n = 20) patients using immunohistochemistry. Our data demonstrate that both HPSE and CTS LmRNA expression were up-regulated in IBC vs. non-IBC patients. According to BC molecular subtypes, HPSE expression was higher in TN than in non-TN of both IBC and non-IBC patients. CTSL mRNA expression was elevated in TN compared to non-TN non-IBC. However, this notion was not evident in TN IBC. Therefore, we suggest that overexpression of HPSE and CTSL may play an important role in the pathogenesis of IBC and their targeting could have therapeutic implications |