Tumor-Associated Adhesion G Protein-Coupled Receptors

Abstract

With more than 800 members in the human genome, G protein-coupled receptors (GPCRs) constitute the largest family of cell surface proteins and are involved in almost every aspect of cellular functions. Among the different groups of GPCRs, the adhesion-class GPCRs (adhesion-GPCRs) are uniquely characterized by a large extracellular domain containing multiple cell-adhesion protein motifs. Adhesion-GPCRs hence play a dual cell adhesion and signaling function. Normally expressed in cells of the central nervous, immune, and reproductive systems, aberrant or unregulated adhesion-GPCR expression has been found in many tumor cell types. Tumor-associated adhesion-GPCRs are thought to be involved in tumorigenesis by affecting the proliferation/survival, migration, invasion and metastasis of tumor cells and angiogenesis, either positively or negatively. Moreover, some adhesion-GPCRs are thought as possible markers of specific tumor cells. Here, we summarize the current development regarding the functional characteristics of the tumor-associated adhesion-GPCRs.