Tag Archives: Osteopontin

Osteopontin – a prognostic marker for cancer progression

Osteopontin (OPN) is a matrix protein that is expressed by osteoclasts, osteoblasts, dendritic cells, fibroblasts, hepatocytes, smooth and skeletal muscle cells, endothelial cells, and kidney cells. It interacts with many cell surface receptors including integrins and CD44. One of the major physiologic functions of OPN is the control of bone mineralization – by binding to specific apatitie crystal faces, it inhibits mineralization. But, OPN is also a pro-inflammatory cytokine that acts in many tissues to recruit monocytes and macrophages and induce cytokine secretion from leukocytes. As such, it has a critical role in tissue remodeling, inflammation, and tumorigenesis. Continue reading