Osteopontin (SPP1) (SPP1)

Osteopontin (SPP1) is a multifunctional, highly phosphorylated matricellular glycoprotein that plays a critical role in bone remodeling, immune response, and tissue repair (UniProt P10451). It is secreted by various cell types, including osteoblasts, macrophages, and activated T-cells, and functions by binding to several integrin receptors and CD44 (NCBI Gene 6696). In the context of disease, SPP1 is significantly upregulated in many cancers, where it promotes tumor progression, metastasis, and an immunosuppressive microenvironment by recruiting myeloid-derived suppressor cells (PMID: 31110139). It also serves as a potent pro-inflammatory cytokine in chronic inflammatory conditions like rheumatoid arthritis and atherosclerosis (PMID: 29410824). Therapeutically, SPP1 is being explored as a target for monoclonal antibodies and aptamers designed to block its interaction with cell surface receptors, thereby inhibiting its pathological signaling. Its levels in biofluids are frequently used as a biomarker for disease severity and prognosis across multiple clinical indications (PMID: 31110139).

Other names

Secreted phosphoprotein 1Bone sialoprotein 1Early T-lymphocyte activation 1Eta-1NephropontinUropontinBNSPOPN

Neutralization of secreted SPP1 to prevent binding to integrin receptors (such as αvβ3, αvβ5, and αvβ1) and CD44, thereby inhibiting downstream signaling pathways like PI3K/Akt and MAPK that drive tumor progression and inflammation (PMID: 31110139).