Monoclonal Antibodies Recognizing Unique Native Structure of PRSS14/Epithin showed Strong Specificity on PRSS14/Epithin

초록

PRSS14/Epithin is a type II transmembrane serine protease and upregulated widely in epithelial type cancers. It is involved in angiogenesis, epithelial mesenchymal transition, transendothelial migration, and metastasis. PRSS14/Epithin is a better prognosis marker than HER2 for ER- breast cancer and a potentially useful therapeutic target for the triple negative breast cancer with poor survival. In order to generate antibody exclusively reacting to PRSS14/Epithin protein, we designed peptide antigen based on the antigenicity, evolutionary conservation, and structural modeling. The chosen epitope of PRSS14/Epithin dose not appear in any other proteins. Five independent monoclonal antibodies were produced using hybridoma technique, and their specificities were verified by competition in ELISA and flow cytometry. These antibodies showed strong specificity on native PRSS14/Epithin protein in various breast cancer cell lines and recombinant PRSS14/Epithin expressed HEK293T cell tested by immunoprecipitation and flow cytometry. The three CDR loops of several antibodies show the nice binding pockets for the designed antigenic epitope in structure modeling. None of the antibodies interfere cell survival or taxol induced cell death of MCF7 cell. More functional studies with cells and animals are currently investigated.