SPARC (Secreted Protein Acidic and Rich in Cysteine), also known as osteonectin or BM-40. is a multifunctional glycoprotein involved in regulating cell-matrix interactions. It is a key component of the extracellular matrix (ECM) and modulates cellular processes such as proliferation, migration, differentiation, and apoptosis by interacting with structural proteins (e.g., collagen) and growth factors (e.g., TGF-β, VEGF). SPARC is highly expressed in tissues undergoing remodeling, including bone, cartilage, and injured or diseased organs, and is implicated in fibrosis, inflammation, angiogenesis, and tumor progression.
SPARC antibodies are tools used to detect and study the protein's expression, localization, and function in both physiological and pathological contexts. In cancer research, SPARC antibodies help assess its dual role as a tumor suppressor (inhibiting cell cycle progression) or tumor promoter (enhancing metastasis via ECM remodeling), depending on cancer type and microenvironment. They are also employed in fibrosis studies (e.g., liver, kidney) and metabolic disorders (e.g., diabetes), where SPARC overexpression correlates with tissue stiffness and dysfunction.
Therapeutically, SPARC antibodies are explored for targeted drug delivery due to SPARC's affinity for albumin and nanoparticles, potentially improving chemotherapy efficacy. However, challenges like off-target effects and variable expression levels across tissues limit clinical applications. Research continues to clarify SPARC's context-dependent mechanisms and optimize antibody-based strategies for diagnostics and treatments.