Abstract

Although several molecular markers for human breast cancer exist, their versatility is limited. Here we demonstrate, through a differential proteome analysis utilizing the fluorogenic derivatization-liquid chromatography/tandem mass spectrometry (FD-LC-MS/MS) method between seven cancer cells and one normal cell, that the presence of cooperatively expressed annexin-2 and galectin-1 without tropomyosin-1 in a tissue could be used to diagnose metastatic breast cancer. Interestingly, in a metastatic cancer cell, the expression of the former two together with highly expressed cofilin-1 activates the Rho signal pathway to aggressively form disorganized actin filaments. Despite the excess expression of annexin-2 and galectin-1 in the normal cell, the highly expressed tropomyosin-1 counteracted the activity of cofilin-1 and stabilized the filaments, resulting in the restoration of the disorganization. This phenomenon suggests that enhancement of tropomyosin-1 should be used as therapy for metastatic breast cancer.