MG7 mimotope-based DNA vaccination for gastric cancer

Abstract

Gastric cancer is still one of the leading causes of cancer-related death worldwide. Prevention and treatment of gastric cancer through vaccination has been difficult owing to lack of a specific target and poor immunity. A number of vaccination strategies have been used to augment immune responses against gastric cancer and some progress has been made. In a series of studies, the authors have focused on gastric cancer vaccination approaches based on MG7 mimotopes, which are mimicry epitopes selected from phage-displayed oligopeptide libraries with a gastric cancer cell-specific monoclonal antibody, MG7-Ab. Strategies employed in these studies include viral or plasmid vectors in combination with carrier sequence or unmethylated CpG with synthetic peptides in nanoemulsion. The results demonstrated that MG7 mimotopes could effectively and specifically induce both cellular and humoral immune reactions and in vivo antitumor responses. In particular, a four-MG7 mimotope DNA vaccine was found to elicit much stronger antitumor immune responses in mice compared with its single-mimotope counterpart. These encouraging findings might pave the way for the development of novel MG7 antigen-based vaccination approaches for human gastric cancer. The review also discusses other immune-enhancing vaccination strategies for gastric cancer.