Designing antibodies to prevent metastasis using epitopes derived from a membrane protease

초록

A member of type Ⅱ transmembrane serine protease (TTSP), epithin, cleaves ECM proteins and activates many well known tumor associated proteins such as PAR-2, pro-HGF, pro-uPA, pro-MMP3. We showed earlier that it is involved in angiogenesis, TGF induced EMT, and metastasis of epithelial cancers. In addition, epithin can modulate epithelial cancer cells to transmigrate through endothelial cells by proteolytically modulating Tie2, an endothelial cell specific membrane tyr kinase. We now selected the epitopes of high antigenicity present from mouse epithin and human ortholog sequences. They were tested in prevention of metastasis using the two breast cancer cell lines and their immunocompetent syngenic mouse hosts, Balb/c (Th2 type) and C57BL6 (Th1 type). Injecting cancer cells into tail veins after Immunization of conjugated peptides in adjuvants reduced metastasis significantly in the sequence specific fashion. Reduction of metastasis was extremely efficient, to the levels of epithin KD cancer cells. Antibody produced by immunization of chosen antigen was mostly Th2 types with alum adjuvant and can block transendothelial migration of 4T1 cancer cells carried with mouse endothelial cell line in transwell plate in vitro.