Osteopontin (MD270R]

Osteopontin, also known as Phosphoprotein 1 (SPP1), is an acidic, calcium-binding glycol-phosphoprotein of 44 to 66 kDa, depending on species and cell type. Osteopontin interacts with integrins and CD44. It has been shown to be multifunctional in cell migration, cell survival, inhibition of calcification, regulation of immune cell function, development and regeneration of skeletal muscle, and control of tumor cell phenotype. Osteopontin is found in all body fluids and secreted by osteoclasts, macrophages, cardiac fibroblasts, and activated T cells. Immunohistochemical analysis shows that Osteopontin is widely expressed in many types of cells including epithelial cells of the gastrointestinal tract, gall bladder, pancreas, urinary and reproductive tracts, lung, breast, salivary glands, and sweat glands. Osteopontin is overexpressed in a variety of human malignancies, including breast, lung, ovarian, gastric, hepatocellular, and prostate carcinomas, mesothelioma, and melanoma. It was proposed to be a potential prognostic marker in ovary cancer, prostate cancer, mesothelioma, and melanoma. In addition, Osteopontin is considered to be a potential marker for atypical teratoid/rhabdoid tumor, a highly malignant central nervous system tumor, commonly seen in infancy and childhood.