Development of a Novel Anti-EpCAM Monoclonal Antibody for Various Applications
Guanjie Li, Hiroyuki Suzuki, Hiroyuki Suzuki, Teizo Asano, Tomohiro Tanaka, Hiroyoshi Suzuki, Hiroyoshi Suzuki, Mika K. Kaneko, Yukinari Kato
Abstract
The epithelial cell adhesion molecule (EpCAM) is a cell surface glycoprotein, which is widely expressed on normal and cancer cells. EpCAM is involved in cell adhesion, proliferation, survival, stemness, and tumorigenesis. Therefore, EpCAM is thought to be a promising target for cancer diagnosis and therapy. In this study, we established anti-EpCAM monoclonal antibodies (mAbs) using the Cell-Based Immunization and Screening (CBIS) method. We characterized them using flow cytometry, Western blotting, and immunohistochemistry. One of the established recombinant anti-EpCAM mAbs, recEpMab-37 (mouse IgG1, kappa), reacted with EpCAM-overexpressed Chinese hamster ovary-K1 cells (CHO/EpCAM) or a colorectal carcinoma cell line (Caco-2). In contrast, recEpMab-37 did not react with EpCAM-knocked out Caco-2 cells. The KD of recEpMab-37 for CHO/EpCAM and Caco-2 was 2.0 × 10−8 M and 3.2 × 10−8 M, respectively. We observed that EpCAM amino acids between 144 to 164 are involved in recEpMab-37 binding. In Western blot analysis, recEpMab-37 detected the EpCAM of CHO/EpCAM and Caco-2 cells. Furthermore, recEpMab-37 could stain formalin-fixed paraffin-embedded colorectal carcinoma tissues by immunohistochemistry. Taken together, recEpMab-37, established by the CBIS method, is useful for detecting EpCAM in various applications.