Description
Bone sialoprotein (BSP) is a phosphorylated glycoprotein that comprises approximately 10% of the total non-collagenous proteins in bone.
BSP is thought to be involved in bone mineralisation and remodelling. BSP is synthesised mainly by skeletal-associated cell types, including fibroblasts, hypertrophic chondrocytes, osteoblasts, osteocytes, osteoclasts, as well as trophoblasts. BSP is overexpressed and underglycosylated in human primary breast and prostate cancers that metastasise to the bone, whereby BSP expression correlates with the development of microcalcifications. Underglycosylated BSP is also expressed by other tumours, such as lung cancer, thyroid cancer, multiple myeloma, and neuroblastoma, that predominantly metastasise to bones.
