Novel CD9-targeted therapies in gastric cancer

Figure 1 Structural features of CD9. CD9 has four putative transmembrane domains, which provide the short N- and C-terminal cytoplasmic domains, a small intracellular loop, and two extracellular loops. C: Cysteine; G: Glycine.

Figure 2 CD9 signaling. CD9-EGFR and CD9-β1 integrin co-localize on the cell surface. CD9 enhances the internalization of EGFR and reduces EGF-EGFR-induced signals[11]. CD9 ligation induced apoptosis via the selective activation of JNK and p38 MAPK pathway as well as caspase-3 and the p46 Shc isoform[26]. CD9 modulates integrin-dependent cell motility, cell migration, adhesion strengthening, and spreading[5,11]. EGFR: Epidermal growth factor receptor; p38 MAPK: p38 mitogen-activated-protein kinase; JNK: c-Jun NH₂-terminal kinase; FAK: Focal adhesion kinase.