Optical Imaging of Mammaglobin Expression in Breast Cancer

摘要

Mammaglobin (MMG) is a breast-specific glycoprotein that is over- expressed in nearly 80% of primary and metastatic breast cancers. The exact biological function of this secreted protein is not known. An important step towards understanding the role of MMG in breast carcinogenesis is to monitor its expression in MMG-expressing tumors. Toward these goals, we prepared 4 truncated MMG peptide analogues, seven MMG-avid peptides, native MMG, and anti- MMG antibodies. These molecules were labeled with near infrared and radioactive probes and evaluated in vivo and in vitro. In vitro assays show that one of these compounds are not cytotoxic, do not induce cell proliferation, and internalized i cells. The in vivo fluorescence imaging and positron emission tomography show similar biodistribution of the probes in mice. Two of the MMG- avid peptides were retained in MMG-positive tumors at higher levels relative to other compounds. These data suggest the feasibility of targeting MMG or its putative receptors for early detection of breast cancer.