102PFunctional characterization of mammagliobin-1 isoform in breast cancer

Background: Since 2007, oncologists have been using the GeneSearchTM Breast Lymph Node (BLN) Assay for the detection of metastatic breast cancer. This test detects the presence of Mammaglobin-1 (MGB1) expression in lymph nodes of breast cancer patients. Although MGB1 is overexpressed in 90% of breast cancers, its aberrant expression and function in breast cancer tissue is still misunderstood. We have recently reported the first evidence for MGB1 as potent induction of breast cancer malignancy and disease progression. More precisely, loss of MGB1 expression correlates with a decrease of cell proliferation, spheroid formation, migration, and invasion capacities of breast cancer cells. Concomitantly, we also show that MGB1 expression activates pro-malignant signaling cascades leading to epithelial to mesenchymal transitioning (EMT). More interestingly, we have also discovered new MGB1 gene products that result from transcript editing. The objective of this research is to elucidate the role of MGB1 gene products in breast cancer, we set out to investigate and characterize MGB1 isoforms in breast cancer cell processes.