OPN/SPP1 His Tag Protein, Human

OPN is an integrin-binding glycoprotein alsoknown as secreted phosphoprotein 1 (SPP1). OPN is so named because it was firstdiscovered in osteoblasts and osteoclasts. The latter is developed from themacrophage lineage. OPN protein has a secreted form and an intracellular form.The secreted OPN has two integrin-binding domains which can adhere to integrinson the surfaces of macrophages, making it a potent chemoattractant as well asan activator of macrophages. In innate immunological cells such as dendriticcells, OPN can be activated upon infection. The OPN-integrin binding cantrigger downstream macrophage activities including TNF secretion, producing aninflammatory microenvironment. Poor prognosis of HCC was correlated withelevated OPN RNA, tissue OPN protein levels and pre-operative serum OPN proteinlevels. An anti-OPN antibody has been shown to defer the growth and metastasisof breast cancer in a mice model. As macrophages can also secret OPN, PTM andOPN form a vicious autocrine/paracrine cycle for the progression of cancer.Thus, in the future, novel strategies to break this cycle could bring to newanti-HCC treatments.