The Role of Anti-LeY Antibody in the Downregulation of MAPKs/COX-2 Pathway in Gastric Cancer

Monoclonal antibody-based treatments of cancer which serve as magic `bullets' have been established as one of the most successful therapeutic strategies. A variety of antigens has been investigated as targets for the mAb therapy of gastric cancer, including the carbohydrate type 2 blood group antigen. Lewis Y (LeY) is overexpressed on tumor cells surface either as glycoproteins or glycolipids. LeY is difucosylated oligosaccharide with the chemical structure [Fuc alpha 1,2Gal beta 1(Fuc alpha 1,3)GlcNAc beta 1 -> R], which is catalyzed by fucosyltransferases, such as FUT1 (alpha 1,2) and FUT4 (alpha 1,3). The role of LeY antigen in cancer treatment and prevention has been extensively studied. Moreover, the cyclooxygenase-2 (COX-2) is an early event protein, highly expressed in H. pylori-related gastric cancer. COX-2 may play a pivotal part in the maintenance of tumor viability, growth, and metastasis. The COX-2 is upregulated in a variety of cancers, including gastric cancer. However, its inhibition may prevent or reverse gastric carcinogenesis. H. pylori mediated alteration of COX-2 through MAPKs pathway is one of the mechanisms that is implicated in gastric cancer. We have found COX-2 and LeY to be correlative sources of specific gastric biomarkers in gastric cancer, which is upregulated in the gastric cancer through MAPKs pathway. In addition, the anti-LeY antibody significantly downregulated the COX-2 expression through MAPKs pathway, helpful to the treatment of gastric cancer. In this review, we summarize the therapeutic effect of anti-LeY antibody, including the crucial role of COX-2 and LeY antigen in gastric cancer and discuss the COX-2 inhibition by anti-LeY antibody through MAPKs pathway.