Role of Novel Matrix-Degrading Metalloproteinase in Breast Cancer Invasion

: The objectives of the present proposal are to identify and clone the protein recognized by the anti-meprin antibody; to study its functional characteristics relevant to invasion; and to examine its prevalence in breast cancer patients. We hypothesized that breast cancer cells are capable of breaking down the extracellular matrix barrier and this plays an important role in breast cancer invasion and metastasis. This study is based on our previous observation that breast cancer tissue expresses a meprin-like protein, which can be identified by immunostaining of breast cancer tissue using anti-meprin antibody. During the first year, our research was focused on the expression of meprin alpha in bacteria and raising antibody to the recombinant protein in order to have a tool for the identification of the meprin-like protein in tissues and extracted proteins. We also performed irnmunohistology studies of human breast tumor and kidney tumor tissues, and produced data on experimental tumor growth with and without inhibition of meprin.