A Survey on the Role of Fetuin-A in Breast Cancer: A Review

Fetuin-A is a major 63-kDa plasma protein synthesized by liver cells and secreted to plasma. It has been suggested to be an extracellular adhesive molecule. In the presence of fetuin-A, breast tumor cells can join and propagate, but the mechanism is not clear. Fetuin-A mediates adhesion by calcium ions, while integrin mediates adhesion by divalent ion manganese and magnesium. Calcium-mediated adhesion is observed in metastatic or more aggressive breast tumor cell line, but not in benign or normal breast epithelial cells. Adhesion and propagation of tumor cells can be only mediated by cellular exosomes carrying histones and fetuin-A. In this article, we review fetuin A and its role in apoptosis and breast cancer.