Isolation and characterization of nanobodies against epithelial cell adhesion molecule as novel theranostic agents for cancer therapy

Epithelial cell adhesion molecule (EpCAM) plays an important role in tumorigenesis. Camelids produce functional antibodies composed of heavy chains only that bind to their antigens via a single domain variable fragment known as nanobody. Nanobodies show multiple advantages over traditional monoclonal antibodies. Isolation anti-EpCAM nanobodies (Nbs) was the main aim this study. An immune nanobody library containing 108 members constructed previously. Anti -EpCAM were isolated from camel using phage display. Four consecutive rounds biopanning performed on immobilized EpCAM. (Nb4, Nb5, Nb22, and Nb23) with highest signal intensity ELISA selected. Affinity these selected for EpCAM nanomolar range. Selected significantly inhibited proliferation MCF-7 cells. The vivo study revealed significant reduction tumor size occurred when treated Nb4 after 14 days monitoring. Our data Nb5 could be considered attractive theranostic agents overexpressing cancers.