Various studies revealed that elevated expression of CD97 in carcinomas is associated with the dedifferentiation, aggressiveness and metastasis of tumour.
Expression of CD97(EGF) in the margins showed a marked difference between the depth of tumor invasion T1 and T2, 3 and 4, and stages I and II/III/IV of gastric carcinomas (P<0.05).
CD97, a membrane protein expressed at high levels on inflammatory cells and some carcinomas, is a member of the adhesion G protein-coupled receptor family, whose members have bipartite structures consisting of an extracellular peptide containing adhesion motifs noncovalently coupled to a class B 7-transmembrane domain.
Our results suggest that CD97(stalk) is probably involved in the growth, invasion and aggressiveness of gastric carcinomas by binding its cellular ligand CD55.
Carcinomas with more strongly CD97-stained scattered tumor cells showed a poorer clinical stage as well as increased lymph vessel invasion compared to cases with uniform CD97 staining.
Taken together, significant numbers of gastric, esophageal, and pancreatic carcinomas are CD97+, whereas its homolog, EMR2, does not have any role in such tumors.