Syndecan-1 (SDC1) (SDC1)

Syndecan-1 (SDC1), also known as CD138, is a type I transmembrane heparan sulfate proteoglycan (HSPG) that serves as a critical co-receptor on the cell surface (UniProt P18827). The functional complex consists of a core protein covalently modified with heparan sulfate (HS) glycosaminoglycan chains, which enable the molecule to bind and sequester various growth factors, chemokines, and extracellular matrix components (PMID: 21639171). These interactions facilitate essential biological processes such as cell-matrix adhesion, migration, and the modulation of signaling pathways like Wnt and TGF-beta (PMID: 30111901). In clinical pathology, SDC1 is highly overexpressed in multiple myeloma and several solid tumors, where it promotes tumor cell survival, angiogenesis, and metastasis (PMID: 25633481). The extracellular domain of SDC1 can be proteolytically shed from the cell surface, producing a soluble form (sCD138) that acts as a potent biomarker for disease progression and poor prognosis in hematological malignancies. Therapeutic strategies targeting the SDC1 complex include antibody-drug conjugates (ADCs) like indatuximab ravtansine and immunocytokines like modakafusp alfa, which leverage the high expression of CD138 to deliver cytotoxic or immune-modulating payloads directly to the tumor microenvironment.

Other names

CD138SYND1Syndecan proteoglycan 1Heparan sulfate proteoglycan 1

Antibody-drug conjugate (ADC) mediated delivery of cytotoxic agents and immunocytokine-mediated activation of immune signaling.