Membrane type-1 matrix metalloproteinase (MT1-MMP) correlates with the expression and activation of matrix metalloproteinase-2 (MMP-2) in inflammatory breast cancer.

Inflammatory breast cancer (IBC) represents the most aggressive form of breast cancer, characterized by rapid progression, involvement of dermal lymphatic emboli and extensive metastatic lymph nodes. Matrix metalloproteinases (MMPs) are proteolytic enzymes that play an important role in cancer invasion and metastasis. Although the role of MMPs in non-IBC is well studied, little is known about its role in IBC. Thus the goal of the present study was to 1) investigate the expression and activity levels of membrane type matrix metalloproteinase-1 (MT1-MMP) and matrix metalloproteinase-2 and-9 (MMP-2 and MMP-9) in IBC versus non-IBC tissue samples and; 2) test correlation between expression of MT1-MMP and pro- and active forms of MMP-2 and MMP-9. We enrolled 51 breast cancer patients, 21 were diagnosed as IBC and 30 as non-IBC. Level of expression of MT1-MMP in carcinoma tissue was assessed by immunoblot and immunohistochemistry techniques. The expression and activation of MMP-2 and MMP-9 was measured by gelatin zymography. Our results revealed that MT1-MMP, pro-MMP-2, pro-MMP-9 and active MMP-2 were more expressed in IBC tissue versus non-IBC. Furthermore, we found that MT1-MMP expression correlates with expression of pro-MMP-2, pro-MMP-9 and active MMP-2 in IBC tissue samples and with MMP-9 in non-IBC tissue sample. In conclusion, our study suggests a role of MT1-MMP in inflammatory breast cancer disease progression.