GPC1

Glypican-1 (GPC1) is a cell-surface heparan sulfate proteoglycan that belongs to the glypican family. The protein is anchored to the outer leaflet of the plasma membrane by a glycosylphosphatidylinositol (GPI) anchor and carries heparan sulfate chains capable of binding various signaling molecules. The GPC1 gene encodes this protein in humans.

Glypicans modulate signaling pathways by presenting growth factors to their receptors and by shaping the extracellular environment. GPC1, like other glypicans, can influence pathways such as Wnt, Hedgehog, fibroblast growth factor, and vascular endothelial growth factor signaling. Through these interactions, GPC1 participates in processes including cell proliferation, differentiation, migration, and tissue patterning during development, with notable roles in neural and limb formation. It is broadly expressed across tissues, with higher expression in certain developing structures.

In disease, GPC1 is studied for its role in cancer. Some cancers show altered GPC1 expression, and research has examined GPC1-positive exosomes as a potential blood-based biomarker for pancreatic ductal adenocarcinoma. Initial reports suggested high diagnostic accuracy, but subsequent studies produced mixed results, and the clinical utility remains under investigation. Ongoing research aims to clarify the reliability and limitations of GPC1 as a biomarker and to understand its contributions to tumor biology.

Detection and study of GPC1 typically involve antibody-based assays to measure the protein on the cell surface or on isolated exosomes, often after exosome enrichment and characterization. Overall, GPC1 is a developmentally important proteoglycan with potential clinical relevance in oncology, though its utility as a diagnostic tool is not yet established.