The Expression, Regulation, and Biomarker Potential of Glypican-1 in Cancer

Abstract

Glypican-1 (GPC-1) and other glypicans are a family of heparan sulfate proteoglycans. These proteins are highly expressed on the cell membrane and in the extracellular matrix, functioning mainly as modulators of growth factor signaling. Some of them are abnormally expressed in cancer, possibly involved in tumorigenesis, and detectable in blood as potential clinical biomarkers. GPC-1 is another glypican member that has been found to be associated with some cancers, and has increasingly interested the cancer field. Here we provide a brief review about GPC-1 in its expression, signaling and potential as a cancer biomarker.

Keywords: GPC-1; biomarker; cancer; glypican; heparan sulfate proteoglycan.

Figure 1

GPC-1 modulates signaling pathways in cancer progression. The HS side chains of GPC-1 bind both growth factors (such as VEGF-A, FGF-2, and TGF-β) and their receptors, to facilitate their assembly for enhanced signaling in PI3K/AKT, MAPK, Smad pathways. GPC-1 can be cleaved by Notum and then released into the extracellular space, which can compete with the GPC-1 anchored on the cell membrane to inhibit its function.